TILEC Conference 2013
An Empirical Comparison of the Outcome of Patent Examination in the
USPTO, the EPO and IP Australia
Andrew Christie1, Chris Dent,2 Amanda Lim3
I. INTRODUCTION
The examination of patent applications by patent examiners largely has been a “black box” for
those who comment on the operation of the patent system. That is to say, beyond the content of the
laws that guide the decisions of examiners, little is known about what impact the decisions of
examiners have on the applications that they assess, and in particular the extent to which those
assessments result in different granted patents. To explore this issue is important, because it is the
examination process that dictates the existence, and scope, of the monopoly that is granted for an
invention – and, hence, the quality of the patent. If the examination processes in different offices
produces different outcomes, this is evidence of a lack of harmony in the system – and, possibly, of
a difference in quality. This article is the second phase of a suite of work by us that explores these
issues.4
To undertake this phase of the research, we analysed the process, and the outcome, of examination
by three different patent offices of a sample of identical patent applications. The offices are the
United States Patent Office (USPTO), the European Patent Office (EPO), and the Australian Patent
Office (APO).5 The USPTO and the EPO were chosen as they are two of the three trilateral patent
1
Professor of Intellectual Property, Melbourne Law School, University of Melbourne, 3010, Australia; +61 3 8344
6201; a.christie@unimelb.edu.au
2
Principal Research Fellow, Intellectual Property Research Institute of Australia, University of Melbourne
3
Patent Examiner, IP Australia, and formerly Research Fellow, Intellectual Property Research Institute of Australia,
University of Melbourne
4
The results of the first phase of our work have been presented by the first-named author at the European Policy for
Intellectual Property (EPIP) association conference in 2010, and a paper on that work is currently pending.
5
The Australian Patent Office is formally known as IP Australia.
offices and the two that examine patent applications in English. The APO was included as it is the
national office of the researchers and because the project was financially supported by the office.6
The focus in this phase of our work is on two things – the extent to which claims granted by patent
offices are different (where the claims in the applications were identical), and the grounds of
objection that gave rise to the observed differences.7 A comparison of the differences between
granted claims provides insight into the patent examination practices of the patent offices that
granted them. This, in turn, offers insight into the extent to which the patent laws of the
jurisdictions are similar. Having evidence as to the current level of harmonisation is important in
terms of any future proposals for increasing (or decreasing) the extent to which the tests of
patentability align across the world.
II. METHOD
Two aspects of our method need to be described. The first is procedural, in that it relates to the
selection of the families we analyse and the process of the collection of the required files. The
second aspect is analytic, and contains a description of the processes we used in our analysis.
Sample Selection and Acquisition
The PATSTAT database dated September 2008 was searched to identify patent families that
satisfied three criteria. The first search criterion was that each patent family has at least one
published patent application and at least one published granted patent from each of the USPTO,
EPO and APO. This criterion ensured that all applications in our sample had been prosecuted to
their fullest extent by the patent applicant. If we had included in the sample applications that failed
6
The APO, through its administering agency IP Australia, was a participating organization (together with the Institute
of Patent and Trade Mark Attorneys of Australia) in an Australian Research Council-funded Linkage Project
LP0882034.
7
There is little discussion in the literature about the role of specific tests of patentability in the patent system.
Examples include D. Crouch, ‘An Empirical Study of the Role of the Written Description Requirement in Patent
Examination’ (2010) 104 Northwestern University Law Review 1665; and D. Crouch, ‘Is Novelty Obsolete?
Chronicling the Irrelevance of the Invention Date in US Patent Law’ (2009) 16 Michigan Telecommunications and
Technology Law Review 53.
2
to result in a grant, it would not have been possible to be sure whether the application lapsed
(because the applicant no longer desired a patent in the jurisdiction of that office) or whether the
application could never have proceeded to grant (because it could not have been amended to
comply with the tests of patentability).
The second search criterion was that the published patent application and the published granted
patent from the EPO is in the English language. The reason for this criterion is that it was
necessary to have a common language for the task of comparing granted claims and identifying if
any observed differences were meaningful.
The third search criterion was that each patent family has a patent application in the USPTO with a
date of filing between 1 July 2003 and 31 December 2003. There were no time limitations for the
dates of filing in the EPO or the APO. The particular time limitations of the search criteria were
chosen because actual patent case files were made publicly available through the Patent Application
Information Retrieval (PAIR) database of the USPTO from 1 July 2003 onwards. The number of
patent families identified from the PATSTAT search using these search criteria mentioned was 482.
An important requirement for a comparative analysis of the patent examination process of the three
Patent Offices was that the published application was the same. To assist in this process, only
patent families with patent applications that originated from a single PCT application8 and entered
National Phase9 in the USPTO, EPO and APO were selected for our comparative analyses. That all
the claims in the sample stemmed from PCT applications meant that the claim 1 of each application
was identical. The quality of the claims being identical is important as it means that any differences
in amendments to the claim wrought by the examination process was the result of the national law
and its application by the national office, and not the result of any differences in the claims
themselves. Claim 1 was chosen for our analyses because Claim 1 generally defines the broadest
legal monopoly for the invention of the patent application. Consequently, any changes made to
8
The Patent Cooperation Treaty (PCT) provides for the filing of a single patent application to obtain patent rights for
an invention in any of the contracting PCT member countries and regional designations.
9
The PCT application has an international phase and a national or regional phase. During the national or regional
phase, the relevant national or regional authority undertakes an examination of the patent application using
applicable patent laws of the jurisdiction.
3
Claim 1 during the patent examination will be the most significant in terms of affecting the legal
monopoly of the claimed invention. The number of PCT families that met our criteria was 175.
Of these 175 patent families, there were 59 patent families in which Claim 1 was amended during
the International Phase10 of the PCT application. As the focus of the analysis was the impact of
national examination processes, these 59 patent families were not analysed further. The
amendments to Claim 1 that we compare in our analyses are solely amendments that were made to
Claim 1 during National Phase of the patent application. The sample set for our comparative
analyses contains 116 patent families. This derivation of our sample set is illustrated in Figure 1.
482 patent families identified
from PATSTAT search
307 patent families did not stem
from a single PCT application
175 patent families stemmed
from a single PCT application
59 patent families with
amendments in the PCT
International Phase
116 patent families in sample
Figure 1: Derivation of sample for analysis
In order to compare the effect of the examination processes in each office, the claim as applied for,
and the claim as granted, needed to be accessed. The application Claim 1 and the granted Claim 1
used for our comparative analyses were, respectively, the first published application claim and the
first published granted claim from each patent application. The claims for the US and European
patent applications and granted patents were obtained from publicly available patent databases of
10
During international phase, a prior art search is done to find the most relevant prior art documents regarding the
claimed subject matter. An international search report is issued upon completion of the prior art search. The
applicant may amend the claims of the PCT application during the international phase if an international preliminary
examination is requested. The request of an international preliminary examination is optional.
4
the USPTO11 and EPO.12 The claims for AU patent applications and granted patents were obtained
from an open access patent database.13
In order to examine the examination processes themselves, we needed to read the prosecution
history of the files. That is, we had to read the examination reports of the patent examiners, and the
communications from the patent attorneys, to assess which grounds of patentability drove the
amendments that were filed by the attorneys. The patent case files for US and European patent
applications were obtained from publicly available databases of the USPTO14 and EPO.15 The
patent case files for AU patent applications of this study are not publicly available, and were
obtained from the APO by arrangement with the APO.
Analysis of Granted Claims, and Identification of Meaningful Difference
The first published granted Claim 1 of a patent in our sample from one jurisdiction was compared to
the first published granted Claim 1 of the matched patent application from another jurisdiction to
observe whether there is a difference in scope of legal monopoly between the granted claims of the
two Patent Offices being compared. Determining the difference, if any, between patent claims is a
task routinely undertaken by patent lawyers and patent attorneys (and our team had one of each).
We define two categories of differences that were observed between the granted claims of matched
patent applications from two jurisdictions. These categories are “meaningful difference” and “no
meaningful difference”. We say that there is a “meaningful difference” between two granted claims
when the scope of the legal monopoly of one granted claim is different (in a legal sense) to that of
the corresponding granted claim from another jurisdiction. A difference between claims will be
meaningful, in a legal sense, when one claim defines an invention that is not the same as the
11
The patent databases of the USPTO are publicly available through the website link http://patft.uspto.gov/.
12
The patent databases of the EPO are publicly available through the website link https://data.epo.org/publicationserver/?lg=en
13
Patent Lens is an open access patent database that is available through the website link http://www.patentlens.net/.
14
The Patent Application Information Retrieval (PAIR) database of the USPTO is available through the website link
http://portal.uspto.gov/external/portal/pair.
15
The actual patent case files for European patent applications were obtained from the EPO through the website link
http://www.epo.org/searching/free/register.html.
5
invention defined by another claim – and so the legal monopoly granted by the two patents is
different. Examples of meaningful difference between granted claims are where one granted claim
has an additional or different limitation compared to the other granted claim, and where one granted
claim defines a product claim while the other granted claim defines a process claim.
We considered that there was “no meaningful difference” between two granted claims of matched
patent applications when the scope of legal monopoly defined by the granted claims in both
jurisdictions is the same. Examples of claims in this category include cases where there is no
difference at all between the two granted claims, and cases where the differences between the
claims were in regard to grammar or syntax or number references only and did not change the scope
of legal monopoly of the invention defined by those granted claims.
Where it was found that there was a meaningful difference between two granted claims of matched
patent applications, an assessment was made as to whether a granted claim from one jurisdiction
was narrower than the granted claim from the other jurisdiction. In this study, a narrower granted
claim is a claim that defines more limitations for a claimed invention than the other granted claim.
In other words, a narrower granted claim has a scope that may be understood to be completely
encompassed by the scope of legal monopoly of the other (wider) granted claim. An example of
this would be where a claim in one office was not amended as a result of the examination process in
that office while the claim it was being compared with had been amended through the inclusion of
an additional feature. In that situation, the amended claim is necessarily narrower than the
unamended claim, as the additional feature limits the possibility of infringement.
It was, however, not always possible to assess whether one claim was narrower than the other. In,
for example, the cases where both claims were amended as a result of the patent examination
process, and where the features added by way of amendment were different, it was sometimes not
possible to say which claim (if either) was narrower than the other.
III. RESULTS
Rates of Meaningfully Different Outcomes
The assessment of the meaningful difference between patent grants was carried out on a pair-wise
basis. Figure 2 shows that there is substantial disharmony in outcomes of patent examination across
the three offices, despite the Claim 1s in the applications being identical. Of the three pair-wise
6
comparisons, only the claims granted by the EPO and the APO had more claims that were not
meaningfully different from each other than were meaningfully different from each other.
Figure 2: Proportion of meaningful difference vs. no meaningful difference between granted claims
(n=116)
Direction of Meaningfully Different Outcomes
Table 1 shows the pair-wise analysis of those files that were found to have granted claims that were
meaningfully different from each other. The data shows that claims granted by the USPTO tended
to be narrower than the claims granted by the other two offices; further, the claims granted by the
APO tended to be wider than those granted by the other two offices.16 Less than one-quarter of the
pairs of claims were such that neither of the claims could be adjudged narrower than the other.
16
Our work, therefore, confirms the assertion of Lemley and Sampat – that examination narrows patent claims – an
assertion that they could not test empirically: M. Lemley and B. Sampat, ‘Examining Patent Examination’ (2010)
Stanford Technology Law Review 2, [13].
7
Table 1: Proportion of granted claims narrower than corresponding claim
Patent Offices
compared
US v EP (n=88)
US v AU (n=74)
EP v AU (n=51)
US granted
claim narrower
(%)
56
72
EP granted
claim narrower
(%)
22
AU granted
claim narrower
(%)
9
29
57
Assessment not
determinable
(%)
23
19
14
Types of Amendments leading to Narrowing of Granted Claims
It is to be noted that a claim may be amended so as to a produce a narrower claim at a number of
points in the examination process. The first point is during the PCT International Phase – as stated
above, however, files that were amended at this point were excluded from the sample. A claim may
also be amended after it has entered the PCT National Phase of examination but before the
examiner has commenced examination. An amendment at this point is referred to as a “preliminary
amendment”. Also, a claim may be amended after the examiner has issued an examination report.
Where such an amendment is made to overcome an objection of the examiner, we refer to that type
of amendment as “following examination report” (for this type of amendment, we can link the
amendment to the legal ground raised by the examiner in the objection). It is also possible for an
amendment to be filed at this time that is not intended to overcome an objection – we refer to this as
a “volitional amendment”. Finally, it is also possible that the examiner will suggest a form of
words that will amend the claim to avoid an issue found by the examiner. Where this happens, and
the examiner does not mention a legal ground that founds the issue, we refer to this as an
“examiner’s amendment”.
Table 2 sets out the frequency at which the various types of amendments were the reason for a
narrowing of the granted claim. Notable is the fact that in over 40% of the files in which the
Australian granted claim was narrower than the comparative claim, the Australian claim was
amended otherwise than after an adverse report. Also notable is the total lack of amendments filed
by US attorneys that were not in response to an adverse report from an examiner.
8
Table 2: Procedure by which narrower claim was amended
Type of amendment that produced
narrower claim
Following examiner’s report
Not following Preliminary amendment
examiner’s
Volitional amendment
report
Examiner’s amendment
Narrowed claims (%)
US (n=105)
EP (n=48)
AU (n=22)
76
88
59
20
8
18
0
4
23
4
0
0
Grounds of Objection Resulting in Narrower Granted Claims
Table 3 shows the analysis of the reports of patent examiners for the files in which one claim in a
pair-wise comparison was found to be narrower than the other claim.17 In each office, novelty was
the ground that most often contributed to the narrowing of one granted claim relative to the other
granted claim. For two of the three offices, the other prior art ground, non-obviousness/inventive
step, was the other most common reason for the narrowing of the claim. In the EPO, however, the
non-prior art ground of clarity (definiteness in the US) was more often the reason for amendment to
the claim than was the ground of inventive step (this being the equivalent of obviousness under the
European Patent Convention).
Table 3: Identified grounds that produced the narrower claim
Ground that caused narrowing of
claim
Novelty
Non-obviousness/inventive step
Definiteness/clarity
Other non-prior art grounds18
US (n=80)
49
31
23
21
Number of claims
EP (n=42)
23
17
22
9
AU (n=13)
10
7
7
0
Two features of this analysis should be noted. First, the files here represent a specific subset of the
overall sample in that all files here included an examination report. Not all files across the whole
17
All the files in which a claim granted by an Office was found to be narrower than the claim granted by the other
Office were combined. So, the column in Table 2 for claims granted by the USPTO is the sum of the grounds cited
in the reports in which the US claim was narrower than the EP claim and the grounds cited in the reports in which
the US claim was narrower than the AU claim.
18
In the USPTO, the other non-prior art grounds were unity, non-statutory subject matter, enablement, and written
description. In the EPO, the other non-prior art grounds were unity, support, non-patentable subject matter, and
form and content. In the APO, the other non-prior art grounds were fair basis and unity.
9
sample included an examination report. That is to say, not all amendments to a claim were the
result of an examiner objecting to it on the basis of a legal test – an attorney may, for example, have
filed an amendment after the application entered the national phase of examination (but before
issuance of a national examination report). Where there was no examiner’s report, no legal ground
could be attributed as a cause for the narrowing of the claim. Secondly, multiple grounds of
objection may be, and often were, raised in an examination report. This is why the sum of the
grounds in each column exceeds the number of files in that column.
Prior Art Known to Examiners Narrowing Granted Claims
Figure 3 shows the further analysis of the files in which one claim was found to be narrower than
another. The focus here is the prior art that is known to the examiner when justifying an objection
based on the lack of either novelty or non-obviousness/inventive step.19 We say a piece of prior art
is known to an examiner if it is either included in the International Search Report (ISR) produced
during the International Phase of the PCT process, if the examiner cites the piece of prior art in the
examination report that she or he produces, or if it was referred to in other documentation in the
file.20 So, if a piece of prior art was cited by an examiner in one patent office that was not in the
ISR nor cited in the examination report produced by the other office (or was not in any other
documents produced by the other office), then we consider that there was a difference in the prior
art known by the two offices.
19
The prior art represents the state of the field of knowledge against which the tests of novelty and nonobviousness/inventive step are applied.
20
Also, there were a small number of cases in which the attorney drew, for example, the US examiner’s attention to a
piece of prior art found by an examiner in a different office. Regardless of whether the US examiner cited that piece
of prior art we considered it to be known to the US examiner. In such cases, were the office that found the prior art
to be the USPTO, the EPO or the APO, we considered it to be known to that office, even if the examiner did not cite
the piece of prior art in her or his report.
10
Figure 3: Prior art known to examiners in pair-wise comparisons in which one claim narrower than
the other (first name office is the one granting narrow claim)
In the comparisons involving the files in which the USPTO granted narrower claims than both the
EPO and the APO, there were more pieces of prior art known to the US examiner than were known
to the examiner in either the EPO or the APO. There was a higher level of similarity in the prior art
known to both European and Australian examiners in files in which the claims granted by their
Offices were narrower. That said, in all comparisons, at least one third of the known prior art in the
compared files was different.21
IV. DISCUSSION
One purpose of our research was to explore the extent to which examination processes in the three
offices are harmonised, as judged by the outcome of examination.22 For us, the examination
processes of two offices are harmonised when the examination of identical claims by the two
21
It may be noted that knowing more prior art did not always result in a narrower claim. There were eight files that
contained citations to prior art found only in the ISR in which the granted claim was narrower than the equivalent
claims that had, as part of their examination, citations to prior art beyond just the ISR. In six of these files, the EPO
granted a narrower claim despite the fact that the other office was aware of more prior art. It is worth noting, too,
that in six of these eight files, the only ground that gave rise to the narrower claim was lack of novelty.
22
For a discussion of the history, rationale and some of the policy issues around the harmonisation of patent laws, see
J. Reichman and R. Dreyfuss, ‘Harmonisation without Consensus: Critical Reflections on Drafting a Substantive
Patent Law Treaty’ (2007) 57 Duke Law Journal 85; and A. Stack, International Patent Law:Co-operation,
Harmonization and an Institutional Analysis of WIPO and the WTO, Edward Elgar, Cheltenham, UK, 2011.
11
offices results in the claim granted by each office being not meaningfully different. A glance at the
patent legislation of the US and Australia and at the EPC shows that the rules underpinning patent
examination are not exactly the same.23 This should not be a surprise. Despite the underlying
obligations imposed by the provisions of the TRIPS Agreement,24 these jurisdictions have their own
national laws on the patentability of inventions. The TRIPS Agreement only sets the patentability
standards at a coarse-grained level – it is left to individual countries to implement these standards in
fine-grained form. So, we knew before we started that the national laws on patentability standards
were not harmonised.
It is clear from Figure 1 that there is limited harmonisation of outcome across the three offices in
the study. In particular, our findings show that examination in the USPTO compared with in the
EPO of the same application results in the same granted claim in less that one-quarter of all cases;
in more than three-quarters of the cases, the granted claims are meaningfully different. Although
the rate of harmonisation of outcome in the USPTO compared with in the APO is higher, it is still
the case that the majority (approximately two-thirds) of claims are granted in meaningfully different
form. The highest rate of harmonisation of outcome occurs in the EPO compared with the APO –
but even here only slightly more than one-half of claims are granted in the same form.
As the claims in the patent applications in our sample were identical, the differences in outcome
must be the result of the examination process in the three offices. There are three aspects of that
process that could be contributing to the observed differences. First, the tests for patentability may
be different across the three jurisdictions.
Secondly, the effectiveness of the strategies for
identifying the prior art may vary across the offices. Thirdly, the rigour with which the examiners
23
For example, the language used in the tests for novelty in each office is similar but not identical: ‘A person shall be
entitled to a patent unless [inter alia] the invention was known or used by others in this country, or patented or
described in a printed publication in this or a foreign country, before the invention thereof by the applicant for
patent’ (35 USC s. 102); ‘An invention shall be considered to be new if it does not form part of the state of the art’
(European Patent Convention, Art. 54(1)); ‘An invention is a patentable invention … if the invention, so far as
claimed in any claim … (b) when compared with the prior art base as it existed before the priority date of that claim:
(i) is novel’ (Patents Act 1990 (Cth), s. 18(1)).
24
Agreement on Trade-related Aspects of Intellectual Property Rights of 1994; being Annexe 1C to the Agreement
Establishing the World Trade Organization, April 15, 1994.
12
apply the legal tests to the claim may differ. Of course, the observed differences between the three
offices may be a result of a combination of the three aspects.
Our further analyses sought to probe which of these factors may be contributing to the substantial
disharmony in the outcome of patent examination that we observed. By attributing, where possible,
a direction to meaningful differences where they occurred, we found that examination in the
USPTO generally resulted in narrower claims – at 2.5 times the rate of narrowing found when
compared with the EPO, and at 9 times the rate when compared with APO. By identifying, where
possible, the examiner’s grounds of objection that led to narrower claims, we found that the prior
art-based grounds of objection of lack of novelty and of obviousness were the most common reason
for amendment in the USPTO. This suggests that these grounds of objection are either more
stringent (in the sense that the legal tests set a higher standard) in US than in Europe and Australia,
and/or are more stringently applied (in the sense that the prior art against which the tests are applied
is greater, meaning the tests are more likely to be failed in any particular case) by US examiners
than by the examiners in the other two jurisdictions, or both.
By evaluating the prior art that was considered by the examiners in the three offices when one of
the offices granted a claim in a narrower form, we found that where the USPTO granted a narrower
claim it took into account more prior art than did the APO in nearly two-thirds of cases, and it took
into account more prior art than did the EPO in nearly four-fifths of cases. This appears to be
evidence of two things: the USPTO identifies more prior art than do the other two offices, and the
identification of more prior art generally results in a narrowing of granted claims compared with the
other two offices.
V. CONCLUSION
The fact that the USPTO identifies more prior art than the other two offices, and that this generally
results in comparatively narrower granted claims, suggests that any attempts to harmonise the
outcome of patent examination should have as a major priority the goal of harmonising the prior art
that is considered by all patent offices.
13
Our data suggest that achieving that goal would most likely increase the rate of harmonised
outcomes from patent examination. Moreover, because that goal requires only changes to patent
office practices (better searching, greater exchange of search results), it is likely to be easier,
politically and practically, to achieve than would be the goal of harmonising the patentability tests
across countries, which requires changes to national law.
14