Search for Tomorrow:The Patent Office’s

Growing Reliance on Technology to Locate

Prior Art

Andrew Chinchin @ unc . edu

IPSC 2007

Patent Office Automation

• 1984: Full-text search from 1976 (two terminals)

• 1991: Full-text search from 1971• 1993-94: Desktop access• 1999: EAST, WEST interfaces• 2000: “Big transition”• 2001: Full-text search from 1920

(OCR)• 2005: USPTO completes move to

Alexandria, leaving “shoes” behind

MPEP § 904.02

• General Search Guidelines– Text search is powerful, but

rarely sufficient by itself– “Some combination of text

search with other criteria, in particular classification, would be a normal expectation in most technologies.”

EAST/WEST Supported Queries

• Terms:– Keywords, phrases– Classes, subclasses

• Connectors:– Boolean operators– Proximity operators– Truncation (i.e., stemming)

• Field restrictions

Questions

• Does keyword searching tend to diversify prior art?– Diversity of classes/subclasses?

•Effect of subject matter variations?

– Diversity of ages?•Pre-1976 (1971) citations?•Stratification in citability rate?•Time decay in citability rate?

Data

• Available:– U.S. patents from 1976

• Full text• Citations

– Image File Wrappers from 8/2004• Examiner’s Search Strategy & Results

(ESSR) reports from 2006 (scanned)

• Not available:– Citations derived from search

results– Search engine query logs

ESSR

Synthetic Approach

• Use Moby dictionary M (354,984 words)

• Impute (Citing, Cited) to keyword search if there is a word w є M such that:– w appears in the claims and

detailed descriptions of both Citing and Cited

– w appears in the claims and detailed descriptions of no more than 50 total patents

Growing Reliance on Keyword Search

Technological Classes Amenable to Keyword

Search

Comments

• Stephen Kunin:– Keyword searching is more useful

in “the chemical area where the terms are better defined”

• Nestor Ramirez, MPEP: – Examiners in mechanical arts

tend to look at all the patents in the class; biotech and chemical examiners rely almost entirely on text search

Questions

• Does keyword searching tend to diversify prior art?– Diversity of classes/subclasses?

•Effect of subject matter variations?

– Diversity of ages?•Pre-1976 (1971) citations?•Time decay in citability rate?

– Overall diversity?•Stratification in citability rate?

Classification Diversity:By Subject Matter

Keyword Search Preference

for Post-1976 References

Citability

Alpha

Beta