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Department of Commerce
Patent and Trademark Office
[Docket No. 950531144-5304-02]
RIN 0651-XX02

            Examination Guidelines for Computer-Related Inventions

Agency: Patent and Trademark Office, Commerce.
Action: Notice.
Summary: The Patent and Trademark Office (“Office”) is publishing the
final version of the guidelines to be used in examination of
computer-related inventions.
Effective Date: March 29, 1996.
For Further Information Contact: Karen A. Buchanan by telephone at (703)
305-8607, by facsimile at (703) 305-9373, by electronic mail at
buchanan@uspto.gov, or by mail marked to her attention addressed to
Office of the Solicitor, P.O. Box 15667, Arlington, Va. 22215.
Supplementary Information:

A. Discussion of Public Comments

The Office received forty-six comments in response to the “Request
for Public Comment on the Proposed Examination Guidelines for
Computer-Implemented Inventions” published on June 2, 1995 (60 FR 28778)
and the supporting legal analysis issued on October 3, 1995. The Office
has carefully considered all of the comments, and a number of changes
have been made in response
These changes include: (1) merging the guidelines and the legal
analysis in support of the guidelines into a single document, (2)
changing the subject title of the document from “computer-implemented”
inventions to “computer-related” inventions, (3) clarifying the legal
requirements for statutory subject matter, (4) segmenting the guidelines
into separate statutory requirements for patentability, and (5) ensuring
that the guidelines treated computer-related inventions in the same
manner as inventions in other technologies to avoid creation of an
artificial distinction between hardware-implemented and
software-implemented inventions
Several suggestions have not been adopted. These include: (1)
determining that claims for data structures per se and computer programs
per se are statutory subject matter, (2) determining that claims for
non-functional descriptive material embodied on computer-readable media
are statutory subject matter, and (3) treating claims that infer
functional descriptive material is embodied on computer-readable medium
as claims limited to computer-readable medium embodying the functional
descriptive material. The first two suggestions are addressed in detail
in Section IV.B.1(a)-(c) and the last suggestion is addressed in detail
in Section IV.B.2(d).
Several commentors encouraged the Office to improve its ability to
conduct effective prior art searches. Such encouragement is consistent
with the current Office plan to use automated search tools to
effectively conduct such prior art searches

B. Examination Guidelines for Computer-Related Inventions

I. Introduction

These “Examination Guidelines for Computer-Related Inventions”1
(“Guidelines”) are to assist Office personnel in the examination of
applications drawn to computer-related inventions.2 The Guidelines are
based on the Office’s current understanding of the law and are believed
to be fully consistent with binding precedent of the Supreme Court, the
Federal Circuit and the Federal Circuit’s predecessor courts.
These Guidelines do not constitute substantive rulemaking and hence
do not have the force and effect of law. These Guidelines have been
designed to assist Office personnel in analyzing claimed subject matter
for compliance with substantive law. Rejections will be based upon the
substantive law and it is these rejections which are appealable.
Consequently, any failure by Office personnel to follow the Guidelines
is neither appealable nor petitionable.
The Guidelines alter the procedures Office personnel will follow when
examining applications drawn to computer-related inventions and are
equally applicable to claimed inventions implemented in either hardware
or software. The Guidelines also clarify the Office’s position on
certain patentability standards related to this field of technology.
Office personnel are to rely on these Guidelines in the event of any
inconsistent treatment of issues between these Guidelines and any
earlier provided guidance from the Office.
The Freeman-Walter-Abele3 test may additionally be relied upon in
analyzing claims directed solely to a process for solving a mathematical
Office personnel have had difficulty in properly treating claims
directed to methods of doing business. Claims should not be categorized
as methods of doing business. Instead, such claims should be treated
like any other process claims, pursuant to these Guidelines when
The appendix includes a flow chart of the process Office personnel
will follow in conducting examinations for computer-related inventions.

II. Determine What Applicant Has Invented and Is Seeking to Patent

It is essential that patent applicants obtain a prompt yet complete
examination of their applications. Under the principles of compact
prosecution, each claim should be reviewed for compliance with every
statutory requirement for patentability in the initial review of the
application, even if one or more claims are found to be deficient with
respect to some statutory requirement. Thus, Office personnel should
state all reasons and bases for rejecting claims in the first Office
action. Deficiencies should be explained clearly, particularly when they
serve as a basis for a rejection. Whenever practicable, Office personnel
should indicate how rejections may be overcome and how problems may be
resolved. A failure to follow this approach can lead to unnecessary
delays in the prosecution of the application.
Prior to focusing on specific statutory requirements, Office
personnel must begin examination by determining what, precisely, the
applicant has invented and is seeking to patent,5 and how the claims
relate to and define that invention. Consequently, Office personnel will
no longer begin examination by determining if a claim recites a
“mathematical algorithm.” Rather, they will review the complete
specification, including the detailed description of the invention, any
specific embodiments that have been disclosed, the claims and any
specific utilities that have been asserted for the invention.

A. Identify and Understand Any Practical Application Asserted for the

The subject matter sought to be patented must be a “useful” process,
machine, manufacture or composition of matter, i.e., it must have a
practical application. The purpose of this requirement is to limit
patent protection to inventions that possess a certain level of “real
world” value, as opposed to subject matter that represents nothing more
than an idea or concept, or is simply a starting point for future
investigation or research.6 Accordingly, a complete disclosure should
contain some indication of the practical application for the claimed
invention, i.e., why the applicant believes the claimed invention is
The utility of an invention must be within the “technological” arts.7
A computer-related invention is within the technological arts. A
practical application of a computer-related invention is statutory
subject matter. This requirement can be discerned from the variously
phrased prohibitions against the patenting of abstract ideas, laws of
nature or natural phenomena. An invention that has a practical
application in the technological arts satisfies the utility requirement.8
The applicant is in the best position to explain why an invention is
believed useful. Office personnel should therefore focus their efforts
on pointing out statements made in the specification that identify all
practical applications for the invention. Office personnel should rely
on such statements throughout the examination when assessing the
invention for compliance with all statutory criteria. An applicant may
assert more than one practical application, but only one is necessary to
satisfy the utility requirement. Office personnel should review the
entire disclosure to determine the features necessary to accomplish at
least one asserted practical application.

B. Review the Detailed Disclosure and Specific Embodiments of the
Invention to Determine What the Applicant Has Invented

The written description will provide the clearest explanation of the
applicant’s invention, by exemplifying the invention, explaining how it
relates to the prior art and explaining the relative significance of
various features of the invention. Accordingly, Office personnel should
begin their evaluation of a computer-related invention as follows:

— determine what the programmed computer does when it performs the
processes dictated by the software (i.e., the functionality of the
programmed computer);9

— determine how the computer is to be configured to provide that
functionality (i.e., what elements constitute the programmed computer
and how those elements are configured and interrelated to provide the
specified functionality); and

— if applicable, determine the relationship of the programmed computer
to other subject matter outside the computer that constitutes the
invention (e.g., machines, devices, materials, or process steps other
than those that are part of or performed by the programmed computer).10

Patent applicants can assist the Office by preparing applications
that clearly set forth these aspects of a computer-related invention.

C. Review the Claims

The claims define the property rights provided by a patent, and thus
require careful scrutiny. The goal of claim analysis is to identify the
boundaries of the protection sought by the applicant and to understand
how the claims relate to and define what the applicant has indicated is
the invention. Office personnel must thoroughly analyze the language of
a claim before determining if the claim complies with each statutory
requirement for patentability.
Office personnel should begin claim analysis by identifying and
evaluating each claim limitation. For processes, the claim limitations
will define steps or acts to be performed. For products11, the claim
limitations will define discrete physical structures. The discrete
physical structures may be comprised of hardware or a combination of
hardware and software.
Office personnel are to correlate each claim limitation to all
portions of the disclosure that describe the claim limitation. This is
to be done in all cases, i.e., whether or not the claimed invention is
defined using means or step plus function language. The correlation step
will ensure that Office personnel correctly interpret each claim
The subject matter of a properly construed claim is defined by the
terms that limit its scope. It is this subject matter that must be
examined. As a general matter, the grammar and intended meaning of terms
used in a claim will dictate whether the language limits the claim
scope. Language that suggests or makes optional but does not require
steps to be performed or does not limit a claim to a particular
structure does not limit the scope of a claim or claim limitation.12
Office personnel must rely on the applicant’s disclosure to properly
determine the meaning of terms used in the claims.13 An applicant is
entitled to be his or her own lexicographer, and in many instances will
provide an explicit definition for certain terms used in the claims.
Where an explicit definition is provided by the applicant for a term,
that definition will control interpretation of the term as it is used in
the claim. Office personnel should determine if the original disclosure
provides a definition consistent with any assertions made by
applicant.14 If an applicant does not define a term in the
specification, that term will be given its “common meaning.”15
If the applicant asserts that a term has a meaning that conflicts
with the term’s art-accepted meaning, Office personnel should encourage
the applicant to amend the claim to better reflect what applicant
intends to claim as the invention. If the application becomes a patent,
it becomes prior art against subsequent applications. Therefore, it is
important for later search purposes to have the patentee employ commonly
accepted terminology, particularly for searching text-searchable
Office personnel must always remember to use the perspective of one
of ordinary skill in the art. Claims and disclosures are not to be
evaluated in a vacuum. If elements of an invention are well known in the
art, the applicant does not have to provide a disclosure that describes
those elements. In such a case the elements will be construed as
encompassing any and every art-recognized hardware or combination of
hardware and software technique for implementing the defined requisite
Office personnel are to give claims their broadest reasonable
interpretation in light of the supporting disclosure.16 Where means plus
function language is used to define the characteristics of a machine or
manufacture invention, claim limitations must be interpreted to read on
only the structures or materials disclosed in the specification and
“equivalents thereof.”17 Disclosure may be express, implicit or
inherent. Thus, at the outset, Office personnel must attempt to
correlate claimed means to elements set forth in the written
description. The written description includes the specification and the
drawings. Office personnel are to give the claimed means plus function
limitations their broadest reasonable interpretation consistent with all
corresponding structures or materials described in the specification and
their equivalents. Further guidance in interpreting the scope of
equivalents is provided in the “Examination Guidelines For Claims
Reciting A Means or Step Plus Function Limitation In Accordance With 35
U.S.C. 112, 6th Paragraph” (“Means Plus Function Guidelines”).18
While it is appropriate to use the specification to determine what
applicant intends a term to mean, a positive limitation from the
specification cannot be read into a claim that does not impose that
limitation. A broad interpretation of a claim by Office personnel will
reduce the possibility that the claim, when issued, will be interpreted
more broadly than is justified or intended. An applicant can always
amend a claim during prosecution to better reflect the intended scope of
the claim.
Finally, when evaluating the scope of a claim, every limitation in
the claim must be considered.19 Office personnel may not dissect a
claimed invention into discrete elements and then evaluate the elements
in isolation. Instead, the claim as a whole must be considered.

III. Conduct a Thorough Search of the Prior Art

Prior to classifying the claimed invention under    101, Office
personnel are expected to conduct a thorough search of the prior art.
Generally, a thorough search involves reviewing both U.S. and foreign
patents and non-patent literature. In many cases, the result of such a
search will contribute to Office personnel’s understanding of the
invention. Both claimed and unclaimed aspects of the invention described
in the specification should be searched if there is a reasonable
expectation that the unclaimed aspects may be later claimed. A search
must take into account any structure or material described in the
specification and its equivalents which correspond to the claimed means
plus function limitation, in accordance with 35 U.S.C.    112, sixth
paragraph and the Means Plus Function Guidelines.20

IV. Determine Whether the Claimed Invention Complies with 35 U.S.C.

A. Consider the Breadth of 35 U.S.C.    101 Under Controlling Law

As the Supreme Court has held, Congress chose the expansive language
of    101 so as to include “anything under the sun that is made by
man.”21 Accordingly,    101 of title 35, United States Code, provides:

Whoever invents or discovers any new and useful process, machine,
manufacture, or composition of matter, or any new and useful improvement
thereof, may obtain a patent therefor, subject to the conditions and
requirements of this title.22

As cast,    101 defines four categories of inventions that Congress
deemed to be the appropriate subject matter of a patent; namely,
processes, machines, manufactures and compositions of matter. The latter
three categories define “things” while the first category defines
“actions” (i.e., inventions that consist of a series of steps or acts to
be performed).23
Federal courts have held that    101 does have certain limits. First,
the phrase “anything under the sun that is made by man” is limited by
the text of    101, meaning that one may only patent something that is a
machine, manufacture, composition of matter or a process.24 Second,
101 requires that the subject matter sought to be patented be a “useful”
invention. Accordingly, a complete definition of the scope of    101,
reflecting Congressional intent, is that any new and useful process,
machine, manufacture or composition of matter under the sun that is made
by man is the proper subject matter of a patent. Subject matter not
within one of the four statutory invention categories or which is not
“useful” in a patent sense is, accordingly, not eligible to be patented.
The subject matter courts have found to be outside the four statutory
categories of invention is limited to abstract ideas, laws of nature and
natural phenomena. While this is easily stated, determining whether an
applicant is seeking to patent an abstract idea, a law of nature or a
natural phenomenon has proven to be challenging. These three exclusions
recognize that subject matter that is not a practical application or use
of an idea, a law of nature or a natural phenomenon is not patentable.25
Courts have expressed a concern over “preemption” of ideas, laws of
nature or natural phenomena.26 The concern over preemption serves to
bolster and justify the prohibition against the patenting of such
subject matter. In fact, such concerns are only relevant to claiming a
scientific truth or principle. Thus, a claim to an “abstract idea” is
non-statutory because it does not represent a practical application of
the idea, not because it would preempt the idea.

B. Classify the Claimed Invention as to Its Proper Statutory Category

To properly determine whether a claimed invention complies with the
statutory invention requirements of    101, Office personnel should
classify each claim into one or more statutory or non-statutory
categories. If the claim falls into a non-statutory category, that
should not preclude complete examination of the application for
satisfaction of all other conditions of patentability. This
classification is only an initial finding at this point in the
examination process that will be again assessed after the examination
for compliance with      102, 103 and 112 is completed and before
issuance of any Office action on the merits.
If the invention as set forth in the written description is
statutory, but the claims define subject matter that is not, the
deficiency can be corrected by an appropriate amendment of the claims.
In such a case, Office personnel should reject the claims drawn to
non-statutory subject matter under    101, but identify the features of
the invention that would render the claimed subject matter statutory if
recited in the claim.

1. Non-Statutory Subject Matter

Claims to computer-related inventions that are clearly non-statutory
fall into the same general categories as non-statutory claims in other
arts, namely natural phenomena such as magnetism, and abstract ideas or
laws of nature which constitute “descriptive material.” Descriptive
material can be characterized as either “functional descriptive
material” or “non-functional descriptive material.” In this context,
“functional descriptive material” consists of data structures27 and
computer programs which impart functionality when encoded on a
computer-readable medium. “Non-functional descriptive material” includes
but is not limited to music, literary works and a compilation or mere
arrangement of data.
Both types of “descriptive material” are non-statutory when claimed
as descriptive material per se. When functional descriptive material is
recorded on some computer-readable medium it becomes structurally and
functionally interrelated to the medium and will be statutory in most
cases.28 When non-functional descriptive material is recorded on some
computer-readable medium, it is not structurally and functionally
interrelated to the medium but is merely carried by the medium. Merely
claiming non-functional descriptive material stored in a
computer-readable medium does not make it statutory. Such a result would
exalt form over substance.29 Thus, non-statutory music does not become
statutory by merely recording it on a compact disk. Protection for this
type of work is provided under the copyright law.
Claims to processes that do nothing more than solve mathematical
problems or manipulate abstract ideas or concepts are more complex to
analyze and are addressed below. See sections IV.B.2(d) and IV.B.2(e).

(a) Functional Descriptive Material: “Data Structures” Representing
Descriptive Material Per Se or Computer Programs Representing Computer
Listings Per Se

Data structures not claimed as embodied in computer-readable media
are descriptive material per se and are not statutory because they are
neither physical “things” nor statutory processes.30 Such claimed data
structures do not define any structural and functional
interrelationships between the data structure and other claimed aspects
of the invention which permit the data structure’s functionality to be
realized. In contrast, a claimed computer-readable medium encoded with a
data structure defines structural and functional interrelationships
between the data structure and the medium which permit the data
structure’s functionality to be realized, and is thus statutory.
Similarly, computer programs claimed as computer listings per se,
i.e., the descriptions or expressions of the programs, are not physical
“things,” nor are they statutory processes, as they are not “acts” being
performed. Such claimed computer programs do not define any structural
and functional interrelationships between the computer program and other
claimed aspects of the invention which permit the computer program’s
functionality to be realized. In contrast, a claimed computer-readable
medium encoded with a computer program defines structural and functional
interrelationships between the computer program and the medium which
permit the computer program’s functionality to be realized, and is thus
statutory. Accordingly, it is important to distinguish claims that
define descriptive material per se from claims that define statutory
Computer programs are often recited as part of a claim. Office
personnel should determine whether the computer program is being claimed
as part of an otherwise statutory manufacture or machine. In such a
case, the claim remains statutory irrespective of the fact that a
computer program is included in the claim. The same result occurs when a
computer program is used in a computerized process where the computer
executes the instructions set forth in the computer program. Only when
the claimed invention taken as a whole is directed to a mere program
listing, i.e., to only its description or expression, is it descriptive
material per se and hence non-statutory.
Since a computer program is merely a set of instructions capable of
being executed by a computer, the computer program itself is not a
process and Office personnel should treat a claim for a computer
program, without the computer-readable medium needed to realize the
computer program’s functionality, as non-statutory functional
descriptive material. When a computer program is claimed in a process
where the computer is executing the computer program’s instructions,
Office personnel should treat the claim as a process claim. See Sections
IV.B.2(b)-(e).When a computer program is recited in conjunction with a
physical structure, such as a computer memory, Office personnel should
treat the claim as a product claim. See Section IV.B.2(a).

(b) Non-Functional Descriptive Material

Descriptive material that cannot exhibit any functional
interrelationship with the way in which computing processes are
performed does not constitute a statutory process, machine, manufacture
or composition of matter and should be rejected under    101. Thus,
Office personnel should consider the claimed invention as a whole to
determine whether the necessary functional interrelationship is provided.
Where certain types of descriptive material, such as music,
literature, art, photographs and mere arrangements or compilations of
facts or data,31 are merely stored so as to be read or outputted by a
computer without creating any functional interrelationship, either as
part of the stored data or as part of the computing processes performed
by the computer, then such descriptive material alone does not impart
functionality either to the data as so structured, or to the computer.
Such “descriptive material” is not a process, machine, manufacture or
composition of matter.
The policy that precludes the patenting of non-functional descriptive
material would be easily frustrated if the same descriptive material
could be patented when claimed as an article of manufacture.32 For
example, music is commonly sold to consumers in the format of a compact
disc. In such cases, the known compact disc acts as nothing more than a
carrier for non-functional descriptive material. The purely
non-functional descriptive material cannot alone provide the practical
application for the manufacture.
Office personnel should be prudent in applying the foregoing
guidance. Non-functional descriptive material may be claimed in
combination with other functional descriptive material on a
computer-readable medium to provide the necessary functional and
structural interrelationship to satisfy the requirements of    101. The
presence of the claimed non-functional descriptive material is not
necessarily determinative of non-statutory subject matter. For example,
a computer that recognizes a particular grouping of musical notes read
from memory and upon recognizing that particular sequence, causes
another defined series of notes to be played, defines a functional
interrelationship among that data and the computing processes performed
when utilizing that data, and as such is statutory because it implements
a statutory process.

(c) Natural Phenomena Such as Electricity and Magnetism

Claims that recite nothing but the physical characteristics of a form
of energy, such as a frequency, voltage, or the strength of a magnetic
field, define energy or magnetism, per se, and as such are non-statutory
natural phenomena.33 However, a claim directed to a practical
application of a natural phenomenon such as energy or magnetism is

2. Statutory Subject Matter

(a) Statutory Product Claims35

If a claim defines a useful machine or manufacture by identifying the
physical structure of the machine or manufacture in terms of its
hardware or hardware and software combination, it defines a statutory
A machine or manufacture claim may be one of two types: (1) a claim
that encompasses any and every machine for performing the underlying
process or any and every manufacture that can cause a computer to
perform the underlying process, or (2) a claim that defines a specific
machine or manufacture. When a claim is of the first type, Office
personnel are to evaluate the underlying process the computer will
perform in order to determine the patentability of the product.

(i) Claims that Encompass Any Machine or Manufacture Embodiment of a

Office personnel must treat each claim as a whole. The mere fact that
a hardware element is recited in a claim does not necessarily limit the
claim to a specific machine or manufacture.37 If a product claim
encompasses any and every computer implementation of a process, when
read in light of the specification, it should be examined on the basis
of the underlying process. Such a claim can be recognized as it will:

— define the physical characteristics of a computer or computer
component exclusively as functions or steps to be performed on or by a
computer, and

— encompass any and every product in the stated class (e.g., computer,
computer-readable memory) configured in any manner to perform that

Office personnel are reminded that finding a product claim to encompass
any and every product embodiment of a process invention simply means
that the Office will presume that the product claim encompasses any and
every hardware or hardware platform and associated software
implementation that performs the specified set of claimed functions.
Because this is interpretive and nothing more, it does not provide any
information as to the patentability of the applicant’s underlying
process or the product claim.
When Office personnel have reviewed the claim as a whole and found
that it is not limited to a specific machine or manufacture, they shall
identify how each claim limitation has been treated and set forth their
reasons in support of their conclusion that the claim encompasses any
and every machine or manufacture embodiment of a process. This will
shift the burden to applicant to demonstrate why the claimed invention
should be limited to a specific machine or manufacture.
If a claim is found to encompass any and every product embodiment of
the underlying process, and if the underlying process is statutory, the
product claim should be classified as a statutory product. By the same
token, if the underlying process invention is found to be non-statutory,
Office personnel should classify the “product” claim as a “non-statutory
product.” If the product claim is classified as being a non-statutory
product on the basis of the underlying process, Office personnel should
emphasize that they have considered all claim limitations and are basing
their finding on the analysis of the underlying process.

(ii) Product Claims–Claims Directed to Specific Machines and

If a product claim does not encompass any and every
computer-implementation of a process, then it must be treated as a
specific machine or manufacture. Claims that define a computer-related
invention as a specific machine or specific article of manufacture must
define the physical structure of the machine or manufacture in terms of
its hardware or hardware and “specific software.”38 The applicant may
define the physical structure of a programmed computer or its hardware
or software components in any manner that can be clearly understood by a
person skilled in the relevant art. Generally a claim drawn to a
particular programmed computer should identify the elements of the
computer and indicate how those elements are configured in either
hardware or a combination of hardware and specific software.
To adequately define a specific computer memory, the claim must
identify a general or specific memory and the specific software which
provides the functionality stored in the memory.
A claim limited to a specific machine or manufacture, which has a
practical application in the technological arts, is statutory. In most
cases, a claim to a specific machine or manufacture will have a
practical application in the technological arts.

(iii) Hypothetical Machine Claims Which Illustrate Claims of the Types
Described in Sections IV.B.2(a)(i) and (ii)

Two applicants present a claim to the following process:

A process for determining and displaying the structure of a chemical
compound comprising:

(a) solving the wavefunction parameters for the compound to determine
the structure of a compound; and
(b) displaying the structure of the compound determined in step (a).

Each applicant also presents a claim to the following apparatus:

A computer system for determining the three dimensional structure of
a chemical compound comprising:

(a) means for determining the three dimensional structure of a compound;
(b) means for creating and displaying an image representing a
three-dimensional perspective of the compound.

In addition, each applicant provides the noted disclosures to support
the claims:

Applicant A                     Applicant B

Disclosure      The disclosure describes        The disclosure states
specific software, i.e.,        that it would be a
specific program code           matter of routine skill
segments, that are to           to select an appropriate
be employed to configure a      conventional computer
general purpose                 system and implement the
microprocessor to create        claimed process on that
specific logic circuits.        computer system. The
These circuits are indicated    disclosure does not have
to be the “means”               specific disclosure that
corresponding to the claimed    corresponds to the
means limitations.              two “means” limitations
recited in the claim
(i.e., no specific
software or logic
circuit). The disclosure
does have an explanation
of how to solve the
wavefunction equations
of a chemical
compound, and
indicates that the
solutions of those
wavefunction equations
can be employed to
the physical structure
of the corresponding

Result          Claim defines specific          Claim encompasses any
computer, patentability         computer embodiment
stands independently            of process claim;
from process claim.             patentability stands
or falls with process

Explanation     Disclosure identifies the       Disclosure does not
specific machine                provide any
capable of                      information to
performing the                  distinguish the
indicated functions.            “implementation”
of the process on a
computer from the factors
that will govern
the patentability
determination of the
process per se. As
such, the
patentability of this
apparatus claim will
stand or fall with
that of the process

(b) Statutory Process Claims

A claim that requires one or more acts to be performed defines a
process. However, not all processes are statutory under    101. To be
statutory, a claimed computer-related process must either: (1) result in
a physical transformation outside the computer for which a practical
application in the technological arts is either disclosed in the
specification or would have been known to a skilled artisan (discussed
in (i) below),39 or (2) be limited by the language in the claim to a
practical application within the technological arts (discussed in (ii)
below).40 The claimed practical application must be a further limitation
upon the claimed subject matter if the process is confined to the
internal operations of the computer. If a physical transformation occurs
outside the computer, it is not necessary to claim the practical
application. A disclosure that permits a skilled artisan to practice the
claimed invention, i.e., to put it to a practical use, is sufficient. On
the other hand, it is necessary to claim the practical application if
there is no physical transformation or if the process merely manipulates
concepts or converts one set of numbers into another.
A claimed process is clearly statutory if it results in a physical
transformation outside the computer, i.e., falls into one or both of the
following specific categories (“safe harbors”).

(i) Safe Harbors

— Independent Physical Acts (Post-Computer Process Activity)

A process is statutory if it requires physical acts to be performed
outside the computer independent of and following the steps to be
performed by a programmed computer, where those acts involve the
manipulation of tangible physical objects and result in the object
having a different physical attribute or structure.41 Thus, if a process
claim includes one or more post- computer process steps that result in a
physical transformation outside the computer (beyond merely conveying
the direct result of the computer operation, see Section
IV.B.2(d)(iii)), the claim is clearly statutory.

Examples of this type of statutory process include the following:

— A method of curing rubber in a mold which relies upon updating
process parameters, using a computer processor to determine a time
period for curing the rubber, using the computer processor to determine
when the time period has been reached in the curing process and then
opening the mold at that stage.
— A method of controlling a mechanical robot which relies upon storing
data in a computer that represents various types of mechanical movements
of the robot, using a computer processor to calculate positioning of the
robot in relation to given tasks to be performed by the robot, and
controlling the robot’s movement and position based on the calculated

— Manipulation of Data Representing Physical Objects or Activities
(Pre-Computer Process Activity)

Another statutory process is one that requires the measurements of
physical objects or activities to be transformed outside of the computer
into computer data,42 where the data comprises signals corresponding to
physical objects or activities external to the computer system, and
where the process causes a physical transformation of the signals which
are intangible representations of the physical objects or activities.43

Examples of this type of claimed statutory process include the

— A method of using a computer processor to analyze electrical signals
and data representative of human cardiac activity by converting the
signals to time segments, applying the time segments in reverse order to
a high pass filter means, using the computer processor to determine the
amplitude of the high pass filter’s output, and using the computer
processor to compare the value to a predetermined value. In this example
the data is an intangible representation of physical activity, i.e.,
human cardiac activity. The transformation occurs when heart activity is
measured and an electrical signal is produced. This process has real
world value in predicting vulnerability to ventricular tachycardia
immediately after a heart attack.
— A method of using a computer processor to receive data representing
Computerized Axial Tomography (“CAT”) scan images of a patient,
performing a calculation to determine the difference between a local
value at a data point and an average value of the data in a region
surrounding the point, and displaying the difference as a gray scale for
each point in the image, and displaying the resulting image. In this
example the data is an intangible representation of a physical object,
i.e., portions of the anatomy of a patient. The transformation occurs
when the condition of the human body is measured with X-rays and the
X-rays are converted into electrical digital signals that represent the
condition of the human body. The real world value of the invention lies
in creating a new CAT scan image of body tissue without the presence of
— A method of using a computer processor to conduct seismic
exploration, by imparting spherical seismic energy waves into the earth
from a seismic source, generating a plurality of reflected signals in
response to the seismic energy waves at a set of receiver positions in
an array, and summing the reflection signals to produce a signal
simulating the reflection response of the earth to the seismic energy.
In this example, the electrical signals processed by the computer
represent reflected seismic energy. The transformation occurs by
converting the spherical seismic energy waves into electrical signals
which provide a geophysical representation of formations below the
earth’s surface. Geophysical exploration of formations below the surface
of the earth has real world value.
If a claim does not clearly fall into one or both of the safe
harbors, the claim may still be statutory if it is limited by the
language in the claim to a practical application in the technological

(ii) Computer-Related Processes Limited to a Practical Application in
the Technological Arts

There is always some form of physical transformation within a
computer because a computer acts on signals and transforms them during
its operation and changes the state of its components during the
execution of a process. Even though such a physical transformation
occurs within a computer, such activity is not determinative of whether
the process is statutory because such transformation alone does not
distinguish a statutory computer process from a non-statutory computer
process. What is determinative is not how the computer performs the
process, but what the computer does to achieve a practical application.44
A process that merely manipulates an abstract idea or performs a
purely mathematical algorithm is non-statutory despite the fact that it
might inherently have some usefulness.45 For such subject matter to be
statutory, the claimed process must be limited to a practical
application of the abstract idea or mathematical algorithm in the
technological arts.46 For example, a computer process that simply
calculates a mathematical algorithm that models noise is non-statutory.
However, a claimed process for digitally filtering noise employing the
mathematical algorithm is statutory.

Examples of this type of claimed statutory process include the

— A computerized method of optimally controlling transfer, storage and
retrieval of data between cache and hard disk storage devices such that
the most frequently used data is readily available.
— A method of controlling parallel processors to accomplish
multi-tasking of several computing tasks to maximize computing
— A method of making a word processor by storing an executable word
processing application program in a general purpose digital computer’s
memory, and executing the stored program to impart word processing
functionality to the general purpose digital computer by changing the
state of the computer’s arithmetic logic unit when program instructions
of the word processing program are executed.
— A digital filtering process for removing noise from a digital signal
comprising the steps of calculating a mathematical algorithm to produce
a correction signal and subtracting the correction signal from the
digital signal to remove the noise.

(c) Non-Statutory Process Claims

If the “acts” of a claimed process manipulate only numbers, abstract
concepts or ideas, or signals representing any of the foregoing, the
acts are not being applied to appropriate subject matter. Thus, a
process consisting solely of mathematical operations, i.e., converting
one set of numbers into another set of numbers, does not manipulate
appropriate subject matter and thus cannot constitute a statutory

In practical terms, claims define non-statutory processes if they:

— consist solely of mathematical operations without some claimed
practical application (i.e., executing a “mathematical algorithm”); or
— simply manipulate abstract ideas, e.g., a bid48 or a bubble
hierarchy,49 without some claimed practical application.

A claimed process that consists solely of mathematical operations is
non-statutory whether or not it is performed on a computer. Courts have
recognized a distinction between types of mathematical algorithms,
namely, some define a “law of nature” in mathematical terms and others
merely describe an “abstract idea.”50
Certain mathematical algorithms have been held to be non-statutory
because they represent a mathematical definition of a law of nature or a
natural phenomenon. For example, a mathematical algorithm representing
the formula E=mc2 is a “law of nature”–it defines a “fundamental
scientific truth” (i.e., the relationship between energy and mass). To
comprehend how the law of nature relates to any object, one invariably
has to perform certain steps (e.g., multiplying a number representing
the mass of an object by the square of a number representing the speed
of light). In such a case, a claimed process which consists solely of
the steps that one must follow to solve the mathematical representation
of E=mc2 is indistinguishable from the law of nature and would “preempt”
the law of nature. A patent cannot be granted on such a process.
Other mathematical algorithms have been held to be non-statutory
because they merely describe an abstract idea. An “abstract idea” may
simply be any sequence of mathematical operations that are combined to
solve a mathematical problem. The concern addressed by holding such
subject matter non-statutory is that the mathematical operations merely
describe an idea and do not define a process that represents a practical
application of the idea.
Accordingly, when a claim reciting a mathematical algorithm is found
to define non-statutory subject matter the basis of the    101 rejection
must be that, when taken as a whole, the claim recites a law of nature,
a natural phenomenon, or an abstract idea.

(d) Certain Claim Language Related to Mathematical Operation Steps of a

(i) Intended Use or Field of Use Statements

Claim language that simply specifies an intended use or field of use
for the invention generally will not limit the scope of a claim,
particularly when only presented in the claim preamble. Thus, Office
personnel should be careful to properly interpret such language.51 When
such language is treated as non-limiting, Office personnel should
expressly identify in the Office action the claim language that
constitutes the intended use or field of use statements and provide the
basis for their findings. This will shift the burden to applicant to
demonstrate why the language is to be treated as a claim limitation.

(ii) Necessary Antecedent Step to Performance of a Mathematical
Operation or Independent Limitation on a Claimed Process

In some situations, certain acts of “collecting” or “selecting” data
for use in a process consisting of one or more mathematical operations
will not further limit a claim beyond the specified mathematical
operation step(s). Such acts merely determine values for the variables
used in the mathematical formulae used in making the calculations.52 In
other words, the acts are dictated by nothing other than the performance
of a mathematical operation.53
If a claim requires acts to be performed to create data that will
then be used in a process representing a practical application of one or
more mathematical operations, those acts must be treated as further
limiting the claim beyond the mathematical operation(s) per se. Such
acts are data gathering steps not dictated by the algorithm but by other
limitations which require certain antecedent steps and as such
constitute an independent limitation on the claim.

Examples of acts that independently limit a claimed process involving
mathematical operations include:

— a method of conducting seismic exploration which requires generating
and manipulating signals from seismic energy waves before “summing” the
values represented by the signals;54 and
— a method of displaying X-ray attenuation data as a signed gray scale
signal in a “field” using a particular algorithm, where the antecedent
steps require generating the data using a particular machine (e.g., a
computer tomography scanner).55

Examples of steps that do not independently limit one or more
mathematical operation steps include:

— “perturbing” the values of a set of process inputs, where the subject
matter “perturbed” was a number and the act of “perturbing” consists of
substituting the numerical values of variables;56 and
— selecting a set of arbitrary measurement point values.57

Such steps do not impose independent limitations on the scope of the
claim beyond those required by the mathematical operation limitation.

(iii) Post-Mathematical Operation Step Using Solution or Merely
Conveying Result of Operation

In some instances, certain kinds of post-solution “acts” will not
further limit a process claim beyond the performance of the preceding
mathematical operation step even if the acts are recited in the body of
a claim. If, however, the claimed acts represent some “significant use”
of the solution, those acts will invariably impose an independent
limitation on the claim. A “significant use” is any activity which is
more than merely outputting the direct result of the mathematical
operation. Office personnel are reminded to rely on the applicant’s
characterization of the significance of the acts being assessed to
resolve questions related to their relationship to the mathematical
operations recited in the claim and the invention as a whole.58 Thus, if
a claim requires that the direct result of a mathematical operation be
evaluated and transformed into something else, Office personnel cannot
treat the subsequent steps as being indistinguishable from the
performance of the mathematical operation and thus not further limiting
on the claim. For example, acts that require the conversion of a series
of numbers representing values of a wavefunction equation for a chemical
compound into values representing an image that conveys information
about the three-dimensional structure of the compound and the displaying
of the three-dimensional structure cannot be treated as being part of
the mathematical operations.
Office personnel should be especially careful when reviewing claim
language that requires the performance of “post-solution” steps to
ensure that claim limitations are not ignored.

Examples of steps found not to independently limit a process
involving one or more mathematical operation steps include:

— step of “updating alarm limits” found to constitute changing the
number value of a variable to represent the result of the calculation;59
— final step of magnetically recording the result of a calculation;60
— final step of “equating” the process outputs to the values of the
last set of process inputs found to constitute storing the result of
— final step of displaying result of a calculation “as a shade of gray
rather than as simply a number” found to not constitute distinct step
where the data were numerical values that did not represent anything;62
— step of “transmitting electrical signals representing” the result of

(e) Manipulation of Abstract Ideas Without a Claimed Practical

A process that consists solely of the manipulation of an abstract
idea without any limitation to a practical application is
non-statutory.64 Office personnel have the burden to establish a prima
facie case that the claimed invention taken as a whole is directed to
the manipulation of abstract ideas without a practical application.
In order to determine whether the claim is limited to a practical
application of an abstract idea, Office personnel must analyze the claim
as a whole, in light of the specification, to understand what subject
matter is being manipulated and how it is being manipulated. During this
procedure, Office personnel must evaluate any statements of intended use
or field of use, any data gathering step and any post-manipulation
activity. See section IV.B.2(d) above for how to treat various types of
claim language. Only when the claim is devoid of any limitation to a
practical application in the technological arts should it be rejected
under    101. Further, when such a rejection is made, Office personnel
must expressly state how the language of the claims has been interpreted
to support the rejection.

V. Evaluate Application for Compliance with 35 U.S.C.    112

Office personnel should begin their evaluation of an application’s
compliance with    112 by considering the requirements of    112, second
paragraph. The second paragraph contains two separate and distinct
requirements: (1) that the claim(s) set forth the subject matter
applicants regard as the invention, and (2) that the claim(s)
particularly point out and distinctly claim the invention. An
application will be deficient under    112, second paragraph when (1)
evidence including admissions, other than in the application as filed,
shows applicant has stated that he or she regards the invention to be
different from what is claimed, or when (2) the scope of the claims is
After evaluation of the application for compliance with    112,
second paragraph, Office personnel should then evaluate the application
for compliance with the requirements of    112, first paragraph. The
first paragraph contains three separate and distinct requirements: (1)
adequate written description, (2) enablement, and (3) best mode. An
application will be deficient under    112, first paragraph when the
written description is not adequate to identify what the applicant has
invented, or when the disclosure does not enable one skilled in the art
to make and use the invention as claimed without undue experimentation.
Deficiencies related to disclosure of the best mode for carrying out the
claimed invention are not usually encountered during examination of an
application because evidence to support such a deficiency is seldom in
the record.
If deficiencies are discovered with respect to    112, Office
personnel must be careful to apply the appropriate paragraph of    112.

A. Determine Whether the Claimed Invention Complies with 35 U.S.C.
112, Second Paragraph Requirements

1. Claims Setting Forth the Subject Matter Applicant Regards as Invention

Applicant’s specification must conclude with claim(s) that set forth
the subject matter which the applicant regards as the invention. The
invention set forth in the claims is presumed to be that which applicant
regards as the invention, unless applicant considers the invention to be
something different from what has been claimed as shown by evidence,
including admissions, outside the application as filed. An applicant may
change what he or she regards as the invention during the prosecution of
the application.

2. Claims Particularly Pointing Out and Distinctly Claiming the Invention

Office personnel shall determine whether the claims set out and
circumscribe the invention with a reasonable degree of precision and
particularity. In this regard, the definiteness of the language must be
analyzed, not in a vacuum, but always in light of the teachings of the
disclosure as it would be interpreted by one of ordinary skill in the
art. Applicant’s claims, interpreted in light of the disclosure, must
reasonably apprise a person of ordinary skill in the art of the
invention. However, the applicant need not explicitly recite in the
claims every feature of the invention. For example, if an applicant
indicates that the invention is a particular computer, the claims do not
have to recite every element or feature of the computer. In fact, it is
preferable for claims to be drafted in a form that emphasizes what the
applicant has invented (i.e., what is new rather than old).
A means plus function limitation is distinctly claimed if the
description makes it clear that the means corresponds to well-defined
structure of a computer or computer component implemented in either
hardware or software and its associated hardware platform. Such means
may be defined as:

— a programmed computer with a particular functionality implemented in
hardware or hardware and software;
— a logic circuit or other component of a programmed computer that
performs a series of specifically identified operations dictated by a
computer program; or
— a computer memory encoded with executable instructions representing a
computer program that can cause a computer to function in a particular

The scope of a “means” limitation is defined as the corresponding
structure or material (e.g., a specific logic circuit) set forth in the
written description and equivalents.65 Thus, a claim using means plus
function limitations without corresponding disclosure of specific
structures or materials that are not well-known fails to particularly
point out and distinctly claim the invention. For example, if the
applicant discloses only the functions to be performed and provides no
express, implied or inherent disclosure of hardware or a combination of
hardware and software that performs the functions, the application has
not disclosed any “structure” which corresponds to the claimed means.
Office personnel should reject such claims under    112, second
paragraph. The rejection shifts the burden to the applicant to describe
at least one specific structure or material that corresponds to the
claimed means in question, and to identify the precise location or
locations in the specification where a description of at least one
embodiment of that claimed means can be found. In contrast, if the
corresponding structure is disclosed to be a memory or logic circuit
that has been configured in some manner to perform that function (e.g.,
using a defined computer program), the application has disclosed
“structure” which corresponds to the claimed means.
When a claim or part of a claim is defined in computer program code,
whether in source or object code format, a person of skill in the art
must be able to ascertain the metes and bounds of the claimed invention.
In certain circumstances, as where self-documenting programming code is
employed, use of programming language in a claim would be permissible
because such program source code presents “sufficiently high-level
language and descriptive identifiers” to make it universally understood
to others in the art without the programmer having to insert any
comments.66 Applicants should be encouraged to functionally define the
steps the computer will perform rather than simply reciting source or
object code instructions.

B. Determine Whether the Claimed Invention Complies with 35 U.S.C.
112, First Paragraph Requirements

1. Adequate Written Description

The satisfaction of the enablement requirement does not satisfy the
written description requirement.67 For the written description
requirement, an applicant’s specification must reasonably convey to
those skilled in the art that the applicant was in possession of the
claimed invention as of the date of invention. The claimed invention
subject matter need not be described literally, i.e., using the same
terms, in order for the disclosure to satisfy the description

2. Enabling Disclosure

An applicant’s specification must enable a person skilled in the art
to make and use the claimed invention without undue experimentation. The
fact that experimentation is complex, however, will not make it undue if
a person of skill in the art typically engages in such complex
experimentation. For a computer-related invention, the disclosure must
enable a skilled artisan to configure the computer to possess the
requisite functionality, and, where applicable, interrelate the computer
with other elements to yield the claimed invention, without the exercise
of undue experimentation. The specification should disclose how to
configure a computer to possess the requisite functionality or how to
integrate the programmed computer with other elements of the invention,
unless a skilled artisan would know how to do so without such
For many computer-related inventions, it is not unusual for the
claimed invention to involve more than one field of technology. For such
inventions, the disclosure must satisfy the enablement standard for each
aspect of the invention.69 As such, the disclosure must teach a person
skilled in each art how to make and use the relevant aspect of the
invention without undue experimentation. For example, to enable a claim
to a programmed computer that determines and displays the
three-dimensional structure of a chemical compound, the disclosure must

— enable a person skilled in the art of molecular modeling to
understand and practice the underlying molecular modeling processes; and
— enable a person skilled in the art of computer programming to create
a program that directs a computer to create and display the image
representing the three-dimensional structure of the compound.

In other words, the disclosure corresponding to each aspect of the
invention must be enabling to a person skilled in each respective art.
In many instances, an applicant will describe a programmed computer
by outlining the significant elements of the programmed computer using a
functional block diagram. Office personnel should review the
specification to ensure that along with the functional block diagram the
disclosure provides information that adequately describes each “element”
in hardware or hardware and its associated software and how such
elements are interrelated.70

VI. Determine Whether the Claimed Invention Complies with 35 U.S.C.
102 and 103

As is the case for inventions in any field of technology, assessment
of a claimed computer-related invention for compliance with    102 and
103 begins with a comparison of the claimed subject matter to what is
known in the prior art. If no differences are found between the claimed
invention and the prior art, the claimed invention lacks novelty and is
to be rejected by Office personnel under    102. Once distinctions are
identified between the claimed invention and the prior art, those
distinctions must be assessed and resolved in light of the knowledge
possessed by a person of ordinary skill in the art. Against this
backdrop, one must determine whether the invention would have been
obvious at the time the invention was made. If not, the claimed
invention satisfies    103. Factors and considerations dictated by law
governing    103 apply without modification to computer-related
If the difference between the prior art and the claimed invention is
limited to descriptive material stored on or employed by a machine,
Office personnel must determine whether the descriptive material is
functional descriptive material or non-functional descriptive material,
as described supra in Section IV. Functional descriptive material is a
limitation in the claim and must be considered and addressed in
assessing patentability under    103. Thus, a rejection of the claim as
a whole under    103 is inappropriate unless the functional descriptive
material would have been suggested by the prior art. Non-functional
descriptive material cannot render non-obvious an invention that would
have otherwise been obvious.71

Common situations involving non-functional descriptive material are:

— a computer-readable storage medium that differs from the prior art
solely with respect to non-functional descriptive material, such as
music or a literary work, encoded on the medium,
— a computer that differs from the prior art solely with respect to
non-functional descriptive material that cannot alter how the machine
functions (i.e., the descriptive material does not reconfigure the
computer), or
— a process that differs from the prior art only with respect to
non-functional descriptive material that cannot alter how the process
steps are to be performed to achieve the utility of the invention.

Thus, if the prior art suggests storing a song on a disk, merely
choosing a particular song to store on the disk would be presumed to be
well within the level of ordinary skill in the art at the time the
invention was made. The difference between the prior art and the claimed
invention is simply a rearrangement of non-functional descriptive

VII. Clearly Communicate Findings, Conclusions and Their Bases

Once Office personnel have concluded the above analyses of the
claimed invention under all the statutory provisions, including
101, 112, 102 and 103, they should review all the proposed rejections
and their bases to confirm their correctness. Only then should any
rejection be imposed in an Office action. The Office action should
clearly communicate the findings, conclusions and reasons which support

1 These Guidelines are final and replace the “Proposed Examination
Guidelines for Computer-Implemented Inventions,” 60 FR 28,778 (June 2,
1995) and the supporting legal analysis issued on October 3, 1995.

2 “Computer-related inventions” include inventions implemented in a
computer and inventions employing computer-readable media.

3 In re Abele, 684 F.2d 902, 905-07, 214 USPQ 682, 685-87 (CCPA
1982); In re Walter, 618 F.2d 758, 767, 205 USPQ 397, 406-07 (CCPA
1980); In re Freeman, 573 F.2d 1237, 1245, 197 USPQ 464, 471 (CCPA 1978).

4 See, e.g., In re Toma, 575 F.2d 872, 877-78, 197 USPQ 852, 857
(CCPA 1978); In re Musgrave, 431 F.2d 882, 893, 167 USPQ 280, 289-90
(CCPA 1970). See also In re Schrader, 22 F.3d 290, 297-98, 30 USPQ2d
1455, 1461-62 (Fed. Cir. 1994) (Newman, J., dissenting); Paine, Webber,
Jackson & Curtis, Inc. v. Merrill Lynch, Pierce, Fenner & Smith, Inc.,
564 F. Supp. 1358, 1368-69, 218 USPQ 212, 220 (D. Del. 1983).

5 As the courts have repeatedly reminded the Office: “The goal is to
answer the question “`What did applicants invent?'” Abele, 684 F.2d at
907, 214 USPQ at 687. Accord, e.g., Arrhythmia Research Tech. v.
Corazonix Corp., 958 F.2d 1053, 1059, 22 USPQ2d 1033, 1038 (Fed. Cir.

6 Brenner v. Manson, 383 U.S. 519, 528-36, 148 USPQ 689, 693-96
(1966); In re Ziegler, 992 F.2d 1197, 1200-03, 26 USPQ2d 1600, 1603-06
(Fed. Cir. 1993).

7 See, e.g., Musgrave, 431 F.2d at 893, 167 USPQ at 289-90, cited
with approval in Schrader, 22 F.3d at 297, 30 USPQ2d at 1461 (Newman,
J., dissenting). The definition of “technology” is the “application of
science and engineering to the development of machines and procedures in
order to enhance or improve human conditions, or at least to improve
human efficiency in some respect.” Computer Dictionary 384 (Microsoft
Press, 2d ed. 1994).

8 E.g., In re Alappat, 33 F.3d 1526, 1543, 31 USPQ2d 1545, 1556-57
(Fed. Cir. 1994) (in banc) (quoting Diamond v. Diehr, 450 U.S. 175, 192,
209 USPQ 1, 10 (1981)). See also id. at 1569, 31 USPQ2d at 1578-79
(Newman, J., concurring) (“unpatentability of the principle does not
defeat patentability of its practical applications”) (citing O’Reilly v.
Morse, 56 U.S. (15 How.) 62, 114-19 (1854)); Arrhythmia, 958 F.2d at
1056, 22 USPQ2d at 1036; Musgrave, 431 F.2d at 893, 167 USPQ at 289-90
(“All that is necessary, in our view, to make a sequence of operational
steps a statutory `process’ within 35 U.S.C. 101 is that it be in the
technological arts so as to be in consonance with the Constitutional
purpose to promote the progress of `useful arts.’ Const. Art. 1, sec.

9 Arrhythmia, 958 F.2d at 1057, 22 USPQ2d at 1036:
It is of course true that a modern digital computer manipulates data,
usually in binary form, by performing mathematical operations, such as
addition, subtraction, multiplication, division, or bit shifting, on the
data. But this is only how the computer does what it does. Of importance
is the significance of the data and their manipulation in the real
world, i.e., what the computer is doing.

10 Many computer-related inventions do not consist solely of a
computer. Thus, Office personnel should identify those claimed elements
of the computer-related invention that are not part of the programmed
computer, and determine how those elements relate to the programmed
computer. Office personnel should look for specific information that
explains the role of the programmed computer in the overall process or
machine and how the programmed computer is to be integrated with the
other elements of the apparatus or used in the process.

11 Products may be either machines, manufactures or compositions of
matter. Product claims are claims that are directed to either machines,
manufactures or compositions of matter.

12 Examples of language that may raise a question as to the limiting
effect of the language in a claim:

(a) statements of intended use or field of use,
(b) “adapted to” or “adapted for” clauses,
(c) “wherein” clauses, or
(d) “whereby” clauses.

This list of examples is not intended to be exhaustive.

13 Markman v. Westview Instruments, 52 F.3d 967, 980, 34 USPQ2d 1321,
1330 (Fed. Cir.) (in banc), cert. granted, 116 S. Ct. 40 (1995).

14 See, e.g., In re Paulsen, 30 F.3d 1475, 1480, 31 USPQ2d 1671, 1674
(Fed. Cir. 1994) (inventor may define specific terms used to describe
invention, but must do so “with reasonable clarity, deliberateness, and
precision” and, if done, must “`set out his uncommon definition in some
manner within the patent disclosure’ so as to give one of ordinary skill
in the art notice of the change” in meaning) (quoting Intellicall, Inc.
v. Phonometrics, Inc., 952 F.2d 1384, 1387-88, 21 USPQ2d 1383, 1386
(Fed. Cir. 1992)).

15 Id. at 1480, 31 USPQ2d at 1674.

16 See, e.g., In re Zletz, 893 F.2d 319, 321-22, 13 USPQ2d 1320, 1322
(Fed. Cir. 1989) (“During patent examination the pending claims must be
interpreted as broadly as their terms reasonably allow . . . The reason
is simply that during patent prosecution when claims can be amended,
ambiguities should be recognized, scope and breadth of language
explored, and clarification imposed . . . An essential purpose of patent
examination is to fashion claims that are precise, clear, correct, and
unambiguous. Only in this way can uncertainties of claim scope be
removed, as much as possible, during the administrative process.”).

17 Two in banc decisions of the Federal Circuit have made clear that
the Office is to interpret means plus function language according to 35
U.S.C.    112, sixth paragraph. In the first, In re Donaldson, 16 F.3d
1189, 1193, 29 USPQ2d 1845, 1848 (Fed. Cir. 1994), the court held:

The plain and unambiguous meaning of paragraph six is that one
construing means-plus-function language in a claim must look to the
specification and interpret that language in light of the corresponding
structure, material, or acts described therein, and equivalents thereof,
to the extent that the specification provides such disclosure. Paragraph
six does not state or even suggest that the PTO is exempt from this
mandate, and there is no legislative history indicating that Congress
intended that the PTO should be. Thus, this court must accept the plain
and precise language of paragraph six.

Consistent with Donaldson, in the second decision, Alappat, 33 F.3d
at 1540, 31 USPQ2d at 1554, the Federal Circuit held:

Given Alappat’s disclosure, it was error for the Board majority to
interpret each of the means clauses in claim 15 so broadly as to “read
on any and every means for performing the function” recited, as it said
it was doing, and then to conclude that claim 15 is nothing more than a
process claim wherein each means clause represents a step in that
process. Contrary to suggestions by the Commissioner, this court’s
precedents do not support the Board’s view that the particular apparatus
claims at issue in this case may be viewed as nothing more than process

18 1162 O.G. 59 (May 17, 1994).

19 See, e.g., Diamond v. Diehr, 450 U.S. at 188-89, 209 USPQ at 9
(“In determining the eligibility of respondents’ claimed process for
patent protection under    101, their claims must be considered as a
whole. It is inappropriate to dissect the claims into old and new
elements and then to ignore the presence of the old elements in the
analysis. This is particularly true in a process claim because a new
combination of steps in a process may be patentable even though all the
constituents of the combination were well known and in common use before
the combination was made.”).

20 See supra note 18 and accompanying text.

21 Diamond v. Chakrabarty, 447 U.S. 303, 308-09, 206 USPQ 193, 197

In choosing such expansive terms as “manufacture” and “composition of
matter,” modified by the comprehensive “any,” Congress plainly
contemplated that the patent laws would be given wide scope. The
relevant legislative history also supports a broad construction. The
Patent Act of 1793, authored by Thomas Jefferson, defined statutory
subject matter as “any new and useful art, machine, manufacture, or
composition of matter, or any new or useful improvement [thereof].” Act
of Feb. 21, 1793,    1, 1 Stat. 319. The Act embodied Jefferson’s
philosophy that “ingenuity should receive a liberal encouragement.” 5
Writings of Thomas Jefferson 75-76 (Washington ed. 1871). See Graham v.
John Deere Co., 383 U.S. 1, 7-10 (1966). Subsequent patent statutes in
1836, 1870, and 1874 employed this same broad language. In 1952, when
the patent laws were recodified, Congress replaced the word “art” with
“process,” but otherwise left Jefferson’s language intact. The Committee
Reports accompanying the 1952 Act inform us that Congress intended
statutory subject matter to “include anything under the sun that is made
by man.” S. Rep. No. 1979, 82d Cong., 2d Sess. 5 (1952); H.R. Rep. No.
1923, 82d Cong., 2d Sess. 6 (1952).

This perspective has been embraced by the Federal Circuit:

The plain and unambiguous meaning of    101 is that any new and
useful process, machine, manufacture, or composition of matter, or any
new and useful improvement thereof, may be patented if it meets the
requirements for patentability set forth in Title 35, such as those
found in      102, 103, and 112. The use of the expansive term “any” in
101 represents Congress’s intent not to place any restrictions on the
subject matter for which a patent may be obtained beyond those
specifically recited in    101 and the other parts of Title 35 . . .
Thus, it is improper to read into    101 limitations as to the subject
matter that may be patented where the legislative history does not
indicate that Congress clearly intended such limitations. [Alappat, 33
F.3d at 1542, 31 USPQ2d at 1556.]

22 35 U.S.C.    101 (1994).

23 See 35 U.S.C.    100(b) (“The term `process’ means process, art,
or method, and includes a new use of a known process, machine,
manufacture, composition of matter, or material.”).

24 E.g., Alappat, 33 F.3d at 1542, 31 USPQ2d at 1556; In re
Warmerdam, 33 F.3d 1354, 1358, 31 USPQ2d 1754, 1757 (Fed. Cir. 1994).

25 See, e.g., Rubber-Tip Pencil Co. v. Howard, 87 U.S. 498, 507
(1874) (“idea of itself is not patentable, but a new device by which it
may be made practically useful is”); Mackay Radio & Telegraph Co. v.
Radio Corp. of America, 306 U.S. 86, 94 (1939) (“While a scientific
truth, or the mathematical expression of it, is not patentable
invention, a novel and useful structure created with the aid of
knowledge of scientific truth may be.”); Warmerdam, 33 F.3d at 1360, 31
USPQ2d at 1759 (“steps of `locating’ a medial axis, and `creating’ a
bubble hierarchy . . . describe nothing more than the manipulation of
basic mathematical constructs, the paradigmatic `abstract idea'”).

26 The concern over preemption was expressed as early as 1852. See Le
Roy v. Tatham, 55 U.S. 156, 175 (1852) (“A principle, in the abstract,
is a fundamental truth; an original cause; a motive; these cannot be
patented, as no one can claim in either of them an exclusive right.”);
Funk Brothers Seed Co. v. Kalo Inoculant Co., 333 U.S. 127, 132, USPQ
280, 282 (1948) (combination of six species of bacteria held to be
non-statutory subject matter).

27 The definition of “data structure” is “a physical or logical
relationship among data elements, designed to support specific data
manipulation functions.” The New IEEE Standard Dictionary of Electrical
and Electronics Terms 308 (5th ed. 1993).

28 Compare In re Lowry, 32 F.3d 1579, 1583-84, 32 USPQ2d 1031, 1035
(Fed. Cir. 1994) (claim to data structure that increases computer
efficiency held statutory) and Warmerdam, 33 F.3d at 1360-61, 31 USPQ2d
at 1759 (claim to computer having specific memory held statutory
product-by-process claim) with Warmerdam, 33 F.3d at 1361, 31 USPQ2d at
(claim to a data structure per se held non-statutory).

29 In re Sarkar, 588 F.2d 1330, 1333, 200 USPQ 132, 137 (CCPA 1978):

[E]ach invention must be evaluated as claimed; yet semantogenic
considerations preclude a determination based solely on words appearing
in the claims. In the final analysis under    101, the claimed
invention, as a whole, must be evaluated for what it is.
Quoted with approval in Abele, 684 F.2d at 907, 214 USPQ at 687. See
also In re Johnson, 589 F.2d 1070, 1077, 200 USPQ 199, 206 (CCPA 1978)
(“form of the claim is often an exercise in drafting”).

30 See, e.g., Warmerdam, 33 F.3d at 1361, 31 USPQ2d at 1760 (claim to
a data structure per se held non-statutory).

31 Computer Dictionary 210 (Microsoft Press, 2d ed. 1994):

Data consists of facts, which become information when they are seen
in context and convey meaning to people. Computers process data without
any understanding of what that data represents.

32 See supra note 29.

33 O’Reilly v. Morse, 56 U.S. (15 How.) at 112-14.

34 Id. at 114-19.

35 Products may be either machines, manufactures or compositions of

A machine is:

a concrete thing, consisting of parts or of certain devices and
combinations of devices.

Burr v. Duryee, 68 U.S. (1 Wall.) 531, 570 (1863).

A manufacture is:

the production of articles for use from raw or prepared materials by
giving to these materials new forms, qualities, properties or
combinations, whether by hand-labor or by machinery.

Diamond v. Chakrabarty, 447 U.S. at 308, 206 USPQ at 196-97 (quoting
American Fruit Growers, Inc. v. Brogdex Co., 283 U.S. 1, 11 (1931).

A composition of matter is:

a composition[] of two or more substances [or] . . . a[] composite
article[], whether . . . [it] be the result of chemical union, or of
mechanical mixture, whether . . . [it] be [a] gas[], fluid[], powder[],
or solid[].

Diamond v. Chakrabarty, 447 U.S. at 308, 206 USPQ at 197 (quoting Shell
Development Co. v. Watson, 149 F. Supp. 279, 280, 113 USPQ 265, 266
(D.D.C. 1957), aff’d per curiam, 252 F.2d 861, 116 USPQ 428 (D.C. Cir.

36 See, e.g., Lowry, 32 F.3d at 1583, 32 USPQ2d at 1034-35;
Warmerdam, 33 F.3d at 1361-62, 31 USPQ2d at 1760.

37 Cf. In re Iwahashi, 888 F.2d 1370, 1374-75, 12 USPQ2d 1908,
1911-12 (Fed. Cir. 1989), cited with approval in Alappat, 33 F.3d at
1544 n.24, 31 USPQ2d at 1558 n.24.

38 “Specific software” is defined as a set of instructions
implemented in a specific program code segment. See Computer Dictionary
78 (Microsoft Press, 2d ed. 1994) for definition of “code segment.”

39 See Diamond v. Diehr, 450 U.S. at 183-84, 209 USPQ at 6 (quoting
Cochrane v. Deener, 94 U.S. 780, 787-88 (1877) (“A [statutory] process
is a mode of treatment of certain materials to produce a given result.
It is an act, or a series of acts, performed upon the subject-matter to
be transformed and reduced to a different state or thing . . . . The
process requires that certain things should be done certain substances,
and in a certain order; but the tools to be used in doing this may be of
secondary consequence.”).

40 See Alappat, 33 F.3d at 1543, 31 USPQ2d at 1556-57 (quoting
Diamond v. Diehr, 450 U.S. at 192, 209 USPQ at 10). see also id. at
1569, 31 USPQ2d at 1578-79 (Newman, J., concurring) (“unpatentability of
the principle does not defeat patentability of its practical
applications”) (citing O’Reilly v. Morse, 56 U.S. (15 How.) at 114-19).

41 Diamond v. Diehr, 450 U.S. at 187, 209 USPQ at 8.

42 See In re Gelnovatch, 595 F.2d 32, 41 n.7, 201 USPQ 136, 145 n.7
(CCPA 1979) (data-gathering step did not measure physical phenomenon).

43 Schrader, 22 F.3d at 294, 30 USPQ2d at 1459 citing with approval
Arrhythmia, 958 F.2d at 1058-59, 22 USPQ2d at 7-38; Abele, 684 F.2d at
909, 214 USPQ at 688; In re Taner, 681 F.2d 787, 790, 214 USPQ 678, 681
(CCPA 1982).

44 See supra note 9.

45 In Sarkar, 588 F.2d at 1335, 200 USPQ at 139, the court explained
why this approach must be followed:

No mathematical equation can be used, as a practical matter, without
establishing and substituting values for the variables expressed
therein. Substitution of values dictated by the formula has thus been
viewed as a form of mathematical step. If the steps of gathering and
substituting values were alone sufficient, every mathematical equation,
formula, or algorithm having any practical use would be per se subject
to parenting as a “process” under    101. Consideration of whether the
substitution of specific values is enough to convert the disembodied
ideas present in the formula into an embodiment of those ideas, or into
an application of the formula, is foreclosed by the current state of the

46 See supra note 40.

47 See, e.g., In re Bernhart, 417 F.2d 1395, 1400, 163 USPQ 611, 616
(CCPA 1969).

48 Schrader, 22 F.3d at 293-94, 30 USPQ2d at 1458-59.

49 Warmerdam, 33 F.3d at 1360, 31 USPQ2d at 1759.

50 See, e.g., In re Meyer, 688 F.2d 789, 794-95, 215 USPQ 193, 197
(CCPA 1982) (“Scientific principles, such as the relationship between
mass and energy, and laws of nature, such as the acceleration of
gravity, namely, a=32 ft./sec.2, can be represented in mathematical
format. However, some mathematical algorithms and formulae do not
represent scientific principles or laws of nature; they represent ideas
or mental processes and are simply logical vehicles for communicating
possible solutions to complex problems. The presence of a mathematical
algorithm or formula in a claim is merely an indication that a
scientific principle, law of nature, idea or mental process may be the
subject matter claimed and, thus, justify a rejection of that claim
under 35 USC    101; but the presence of a mathematical algorithm or
formula is only a signpost for further analysis.”). Cf. Alappat, 33 F.3d
at 1543 n.19, 31 USPQ2d at 1556 n.19 in which the Federal Circuit
recognized the confusion:

The Supreme Court has not been clear . . . as to whether such subject
matter is excluded from the scope of    101 because it represents laws
of nature, natural phenomena, or abstract ideas. See Diehr, 450 U.S. at
186 (viewed mathematical algorithm as a law of nature); Benson, 409 U.S.
at 71-72 (treated mathematical algorithm as an “idea”). The Supreme
Court also has not been clear as to exactly what kind of mathematical
subject matter may not be patented. The Supreme Court has used, among
others, the terms “mathematical algorithm,” “mathematical formula,” and
“mathematical equation” to describe types of mathematical subject matter
not entitled to patent protection standing alone. The Supreme Court has
not set forth, however, any consistent or clear explanation of what it
intended by such terms or how these terms are related, if at all.

51 Walter, 618 F.2d at 769, 205 USPQ at 409 (Because none of the
claimed steps were explicitly or implicitly limited to their application
in seismic prospecting activities, the court held that “[a]lthough the
claim preambles relate the claimed invention to the art of seismic
prospecting, the claims themselves are not drawn to methods of or
apparatus for seismic prospecting; they are drawn to improved
mathematical methods for interpreting the results of seismic
prospecting.”). Cf. Alappat, 33 F.3d at 1544, 31 USPQ2d at 1558.

52 Walter, 618 F.2d at 769-70, 205 USPQ at 409.

53 See supra note 45.

54 Taner, 681 F.2d at 788, 214 USPQ at 679.

55 Abele, 684 F.2d at 908, 214 USPQ at 687 (“The specification
indicates that such attenuation data is available only when an X-ray
beam is produced by a CAT scanner, passed through an object, and
detected upon its exit. Only after these steps have been completed is
the algorithm performed, and the resultant modified data displayed in
the required format.”).

56 Gelnovatch, 595 F.2d at 41 n.7, 201 USPQ at 145 n.7 (“Appellants’
claimed step of perturbing the values of a set of process inputs (step
3), in addition to being a mathematical operation, appears to be a
data-gathering step of the type we have held insufficient to change a
nonstatutory method of calculation into a statutory process . . . In
this instance, the perturbed process inputs are not even measured values
of physical phenomena, but are instead derived by numerically changing
the values in the previous set of process inputs.”).

57 Sarkar, 588 F.2d at 1331, 200 USPQ at 135.

58 See Sarkar, 588 F.2d at 1332 n.6, 200 USPQ at 136 n.6
(“post-solution” construction that was being modeled by the mathematical
process not considered in deciding    101 question because applicant
indicated that such construction was not a material element of the

59 Parker v. Flook, 437 U.S. 584, 585, 198 USPQ 193, 195 (1978).

60 Walter, 618 F.2d at 770, 205 USPQ at 409 (“If    101 could be
satisfied by the mere recordation of the results of a nonstatutory
process on some record medium, even the most unskilled patent draftsman
could provide for such a step.”).

61 Gelnovatch, 595 F.2d at 41 n.7, 201 USPQ at 145 n.7.

62 Abele, 684 F.2d at 909, 214 USPQ at 688 (“This claim presents no
more than the calculation of a number and display of the result, albeit
in a particular format. The specification provides no greater meaning to
`data in a field’ than a matrix of numbers regardless of by what method
generated. Thus, the algorithm is neither explicitly nor implicitly
applied to any certain process. Moreover, that the result is displayed
as a shade of gray rather than as simply a number provides no greater or
better information, considering the broad range of applications
encompassed by the claim.”).

63 In re De Castelet, 562 F.2d 1236, 1244, 195 USPQ 439, 446 (CCPA
1977) (“That the computer is instructed to transmit electrical signals,
representing the results of its calculations, does not constitute the
type of `post solution activity’ found in Flook, [437 U.S. 584, 198 USPQ
193 (1978)], and does not transform the claim into one for a process
merely using an algorithm. The final transmitting step constitutes
nothing more than reading out the result of the calculations.”).

64 E.g., Warmerdam, 33 F.3d at 1360, 31 USPQ2d at 1759. See also
Schrader, 22 F.3d at 295, 30 USPQ2d at 1459.

65 See supra note 18 and accompanying text.

66 Computer Dictionary 353 (Microsoft Press, 2d ed. 1994) (definition
of “self-documenting code”).

67 See In re Barker, 559 F.2d 588, 591, 194 USPQ 470, 472 (CCPA
1977), cert. denied, Barker v. Parker, 434 U.S. 1064 (1978) (a
specification may be sufficient to enable one skilled in the art to make
and use the invention, but still fail to comply with the written
description requirement). See also In re DiLeone, 436 F.2d 1404, 1405,
168 USPQ 592, 593 (CCPA 1971).

68 See, e.g., Northern Telecom v. Datapoint Corp., 908 F.2d 931,
941-43, 15 USPQ2d 1321, 1328-30 (Fed. Cir.), cert. denied, Datapoint
Corp. v. Northern Telecom, 498 U.S. 920 (1990) (judgment of invalidity
reversed for clear error where expert testimony on both sides showed
that a programmer of reasonable skill could write a satisfactory program
with ordinary effort based on the disclosure); DeGeorge v. Bernier, 768
F.2d 1318, 1324, 226 USPQ 758, 762-63 (Fed. Cir. 1985) (superseded by
statute with respect to issues not relevant here) (invention was
adequately disclosed for purposes of enablement even though all of the
circuitry of a word processor was not disclosed, since the undisclosed
circuitry was deemed inconsequential because it did not pertain to the
claimed circuit); In re Phillips, 608 F.2d 879, 882-83, 203 USPQ 971,
975 (CCPA 1979) (computerized method of generating printed architectural
specifications dependent on use of glossary of predefined standard
phrases and error-checking feature enabled by overall disclosure
generally defining errors); In re Donohue, 550 F.2d 1269, 1271, 193 USPQ
136, 137 (CCPA 1977) (“Employment of block diagrams and descriptions of
their functions is not fatal under 35 U.S.C. 112, first paragraph,
providing the represented structure is conventional and can be
determined without undue experimentation.”); In re Knowlton, 481 F.2d
1357, 1366-68, 178 USPQ 486, 493-94 (CCPA 1973) (examiner’s contention
that a software invention needed a detailed description of all the
circuitry in the complete hardware system reversed).

69 See In re Naquin, 398 F.2d 863, 866, 158 USPQ 317, 319 (CCPA 1968)
(“When an invention, in its different aspects, involves distinct arts,
that specification is adequate which enables the adepts of each art,
those who have the best chance of being enabled, to carry out the aspect
proper to their specialty.”); Ex parte Zechnall, 194 USPQ 461, 461 (Bd.
App. 1973) (“appellants’ disclosure must be held sufficient if it would
enable a person skilled in the electronic computer art, in cooperation
with a person skilled in the fuel injection art, to make and use
appellants’ invention”).

70 See In re Scarbrough, 500 F.2d 560, 565, 182 USPQ 298, 301-02
(CCPA 1974) (“It is not enough that a person skilled in the art, by
carrying on investigations along the line indicated in the instant
application, and by a great amount of work eventually might find out how
to make and use the instant invention. The statute requires the
application itself to inform, not to direct others to find out for
themselves (citation omitted).”); Knowlton, 481 F.2d at 1367, 178 USPQ
at 493 (disclosure must constitute more than a “sketchy explanation of
flow diagrams or a bare group of program listings together with a
reference to a proprietary computer on which they might be run”). See
also In re Gunn, 537 F.2d 1123, 1127-28, 190 USPQ 402, 405 (CCPA 1976);
In re Brandstadter, 484 F.2d 1395, 1406-07, 17 USPQ 286, 294 (CCPA
1973); and In re Ghiron, 442 F.2d 985, 991, 169 USPQ 723, 727-28 (CCPA

71 Cf. In re Gulack, 703 F.2d 1381, 1385, 217 USPQ 401, 404 (Fed.
Cir. 1983) (when descriptive material is not functionally related to the
substrate, the descriptive material will not distinguish the invention
from the prior art in terms of patentability).

February 16, 1996                                       BRUCE A. LEHMAN
Assistant Secretary of Commerce
and Commissioner of Patents and Trademarks