Report:Google Patent Search/Search Interface/The Search Forms/Advanced Search

Advanced Search

Searchers needing guidance on constructing a more specific or complex search strategy may select the small link to the “Advanced Patent Search” that appears to the right of the main search bar.

The Advanced Search Form.

As seen in the figure above, the advanced search page is really a user-friendly wizard, designed to help those who aren’t familiar with using field qualifiers in the main search bar. This page provides a number search bars for specific data fields, including title, inventor, assignee, US or International (IPC) classification, and issue or filing date. The page also provides several boxes to help users unfamiliar with the Boolean AND, OR or NOT operators, and who do not know that phrase searches can be conducted by enclosing a phrase in quotation marks.

The Advanced Search Form lets users choose up to 100 results per page.

Users are able to choose between 10, 20, 30, 50, and 100 results per page. This preference does not change the total number of results possible.

If desired, the Advanced Search form can restrict searches to only issued patents or published applications. Also, note that date searching in Google Patents can only be conducted on date ranges between months. A new feature introduced in 2008 enables users to limit searches to specific US patent kinds, including:

• Utility patents
• Design patents
• Plant patents
• Defensive publications
• Statutory Invention Registrations (SIRs)
• Reissues - Design patents
• Reissues - Utility patents
• X-patents (pre-1836 US patents)
• X-patents - reissues
• Additional Improvements (AI)

Additional Improvements patents are a series of patents that were issued from 1838 to 1861. The purpose of this kind of document was for inventors to cover "additional improvements" made on their own already-patented devices.^[1] The system has been supplanted by today's current system of continuations. For additional information on searching X-patents in Google Patent Search, see X-Patents in Google Patent Search.

Although it was discussed in the Full Text Coverage section of this article, it bears repeating that both US and IPC classification searching supported by Google Patents is performed on an incomplete and outdated dataset. The US classification search box is labeled in the form as “Current US Classification,” which is incorrect: it has been shown that Google Patents only contains classification data published on the patent at time of issue, and is not updated with the results of subsequent revision and re-classification efforts; therefore the information cannot be called “current.” Users should also assume that international classification (IPC) data is only included in the database as published on the granted documents, and no updates or backfile re-classification efforts are loaded into the system. (For a specific example showing that Google’s classification data is not current, see the Full Text Coverage section of this article.)

Editor's Note:

The omission of a claims search feature is notable here. This could be seen as a disadvantage for anyone wishing to conduct an infringement-type search of legally enforceable claims. Because of its limitations, any search with serious legal implications should NOT be performed solely using Google Patent, but a claims search feature could function as a supplementary tool. The lack of this feature probably just indicates that either the developers were unfamiliar with patent searching practices, or that they did not wish to introduce further OCR errors by attempting to electronically extract the claims as a separate text section in pre-1976 art.

Because the lack of current data, and of maximum limits on the number of hits that can be retrieved and viewed (see The Hit List), accurate and exhaustive classification searching is impossible in Google Patents. Classifications can still be used to narrow a search down when trying to pinpoint relevant hits, but it should be used as sparingly as possible in this database.

Additionally, the limitation of the date range search to be month-specific seems unnecessarily vague. In patent law, specific dates are quite important, and the omission of this search function either betrays a further lack of the developer’s knowledge of the field, or a desire to hide the possibility of OCR errors within specific dates.

Finally, there is some evidence to suggest that Google Patent Search is a very unreliable tool when performing specific classification, company name, and/or inventor name searching. An informal 2008 test of the system's capabilities, performed by patent librarian and blogger Michael White, showed that Google Patent Search performed especially poorly when compared to three other online patent collections. Searches by assignee name, inventor name, title keyword and US patent classification all returned significantly fewer results than other search engines. These results show that Google Patent Search should never be used to perform a comprehensive review of the patent art.^[2] However, this investigation did not test Google Patent's proprietary retrieval algorithm to determine whether keyword searches were likely to bring the most relevant search hits to the forefront, as some users claim. So despite these limitations, it is possible that the appropriate place for Google Patent Search in a prior art searcher's toolbox is as a quick-and-dirty search tool for keyword concepts.