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Using Boolean Operators for Effective Patent Searching: Boolean IP Consulting


The number of patent filings per year keeps surging globally with each coming year because of the increased pace in continuously evolving technologies and market competition. Many patent applications for similar inventions are being filed and the burden on patent examiners to distinguish between those keeps on piling. As a result, many patent applications are rejected because of similar existing patents or prior arts and many non-novel or inventive-step lacking patent applications are erroneously granted after lack of a thorough prior art search. Now the second case may seem beneficial to the assignee of the patent in the initial stages before product launch or licensing-out of the patent, it may pose threat to the validity of the patent at a later stage. In the nutshell, the effort or money invested in granting of the patent or other stages after grant may go futile if the patent gets invalidated.


It is therefore imperative for inventors to know the basics of prior art search during their invention research to understand existing similar technologies or patents. There are many available patent as well non-patent databases that provide reliable prior art information. Most of those allow searching by paying certain subscription fee. However, there are many freely available databases like Google Patent as well that provide decent coverage of main patent jurisdictions. In most free databases, the searching can be done similar to what we do in normal Google search. We input a simple sentence query and the database provides all the relevant hits that include some of the keywords from your query. You have to be lucky enough to get the bang-on prior art using such databases depending on the technology.

However, when it comes to running complex search queries, especially in domains related to Life Sciences and Chemistry, it becomes difficult to identify very similar prior arts on freely available databases. For such cases, paid databases come handy. Most of the paid databases use similar kind of operators (or rather say logic) to identify closely related prior art. The most common ones are the Boolean operators such as AND, OR and NOT. Here are some simple examples:


  • Touch AND Screen: This search finds patents containing both the terms “touch” and “screen”. AND operator always narrows down your search by necessarily including all the terms included in the search.

  • Touch OR Screen: This search finds patents that contain either of the terms “touch” or “screen”. OR operator always expands your search by including atleast any one of the terms included in the search.

  • Touch NOT Screen: This search finds patents that contain the term touch but not screen. NOT always excludes documents with the specified term.


Depending on your requirement, you may use any of these three operators mentioned above. AND operators are mostly used to identify the bang-on prior art documents that disclose all the terms that you have included in your search. OR operators are mostly used to play around safe when the search is not outputting bang-on documents after using AND operator. Using OR operator can provide similar (not bang-on) documents that gives you an idea of your technology and helps you understand the distinguishing aspects of your invention. However, it is recommended while performing novelty searches to initiate the search in the direction from narrowed (i.e. using AND operator) searches to broader (i.e. using OR operator) searches. While conducting Invalidity and FTO searches, it becomes important that not a single similar invention disclosing document is missed. For these cases, the searches must be run broadly (i.e. using OR operator) followed by AND operator to remove the unwanted results. Although the only issue with using OR operator is that it outputs many irrelevant junk documents, it is always recommended to discard the unwanted results from a big chunk than to not knowing what exists. All modern patent search engines have sophisticated relevancy algorithms under the hood. Construct your query containing 10 or more terms, and OR them together. Of course, you’ll likely get well over a million documents that contain at least one of the terms in your big OR’ed query, but the search engine’s relevancy algorithm will return the best matches first. Just make sure your default sort is by the relevancy column. The best matches are those documents that contain the most term hits with the highest frequency. It is likely that only the first hundred or so documents will be truly relevant.


This process, which leverages the Boolean OR operator and the relevancy-sorting algorithm, is repeatable for any technology. Conceivably, you could even do this type of search in a language that you don’t even speak or a technology with which you have no familiarity and still get highly accurate results. Keep in mind that while it is effective, and repeatable, it is not something you can do in 10 minutes. Some veteran patent searchers spend a day or more refining and testing a query, but once it is done, they can save it and reapply it over and over.


Whatever works basically - patent searching can be a very non-linear process and the best and most confident searchers are happy to try a variety of new approaches. After a little practice, you’ll learn to love the Boolean operators and the results it returns.

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