Document Type


Publication Date

Fall 2015


WVU College of Law


This study attempts to determine whether there are common

characteristics between examiners who issue invalidated patents. This

study uses two new patent databases that code for nearly 1.7 million

patents and approximately one thousand patents that were litigated to

a 'final" judgment between 2010 and 2011. This study finds that

approximately one-third of patents that are litigated to final judgment

are found invalid. Most invalidated patents are found in technology

centers 1600, 2600, and 2700, which correspond to biotechnology and

organic chemistry, communications, and computer science, respectively.

Most patents are invalidated on prior art-type novelty and obviousness

grounds. This study also determined that: (1) litigated patents mainly

come from primary examiners (those examiners with more experience),

and (2) primary examiners that grant between thirty and sixty patents

per year are issuing a higher number of invalidated patents.

Interestingly, the highest volume primary examiners (examiners who

on average grant more than one hundred patents per year and have

more than seven years of experience) issue very few litigated patents

that are later found invalid. Most of the patents that were invalidated

in this data set were done so via the prior art language of 35 U.S.C. §§ 102-103. Approximately 77 percent of the prior art references used

to invalidate patents were not found by the US Patent and Trademark

Office (USPTO) during examination. Additionally, 38 percent of the

prior art references used to invalidate patents were US patents or US

patent applications. Of those invalidating references that were US

patents or patent applications, approximately 89 percent were not

found by the examiner. These data imply that improving PTO

searching could improve patent quality.

Original Publication Title

Vanderbilt Journal of Entertainment & Technology Law

Source Citation

18 Vanderbilt Journal of Entertainment & Technology Law 135


This article is included in the Research Repository @ WVU with the permission of the Vanderbilt Journal of Entertainment & Technology Law.



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