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Patentability Searching 101: Start your (Search) Engines!

Posted by Mike Bakke | Jun 06, 2023 | 0 Comments

Patentability searches are one of the most common types of patent searches, but that does not necessarily mean they are the easiest to conduct. Though one can follow a series of steps to complete a basic patentability search, one must first understand when and why a patentability search is used.

Step 1: Coin the Terms (Patentability Searching 101)

Step 2: Choose the Search Engine (Patentability Searching 101)

Step 3: Using Boolean Operators (Patentability Searching 102)

Step 4: Craft the Search String (Patentability Searching 102)

Step 5: Run the Search (Patentability Searching 103)

Step 6: Find Non-Patent Literature (Patentability Searching 103)

Patent practitioners, such as patent attorneys and agents, regularly perform patentability searches before drafting and submitting a patent application to help determine whether an invention will be patentable. When conducting a patentability search, a practitioner's primary goal is determining whether an invention is patentably distinct over prior art references (i.e., any reference published or filed before an inventor's filing date).

Prior art could be almost anything, including, but not limited to:

  • Patents
  • Published patent applications
  • Articles in a journal or magazine
  • Product listings from online retailers

In a patentability search, prior art references are sought that are similar enough to the invention, or part of the invention, to possibly cause the United States Patent and Trademark Office (USPTO) to believe that the invention is not new or is something obvious compared to these prior art references (i.e., not patentably distinct when compared to the prior art).

Patent practitioners will review and analyze each identified reference to determine which of these references might be most relevant to the proposed invention. In the case of a professional patentability report, the inventor is provided with all this information in the form of an itemized report to help them better determine how to proceed with protecting their invention. Now that one can understand the when and why of carrying out a patentability search, one can begin performing the steps to complete the search.

Step 1: Coin the Terms

The first step of conducting a patentability search is coining search terms. A searcher, ideally a patent practitioner, often begins by coming up with as many descriptive words for the invention as possible and adding them to a word ladder. A word ladder is, in its most basic form, a list of search terms that allows the searcher to quickly reference what words they already have, as well as what words are synonyms for these search terms. It is important to create a word ladder with words specific to the invention but still broad enough that, when used to search, there will be many relevant results. Usually, a word ladder will include about 10-20 words in total.

Once a searcher creates their word ladder, they often determine what synonyms of those words might help improve their search. For example, if the invention is a turkey frier, some synonyms they might want to use for turkey would be words like bird, fowl, or even other types of birds like chicken. By using these synonyms in the search, there is a higher chance that the searcher will get broader results that would not have been included if they just used the word turkey. So, a searcher using these example synonyms would be able to find results such as a patent titled “Deep fat fowl frier,” which the USPTO would likely consider prior art for the turkey frier invention, whereas a searcher that is not using synonyms in their search might not get such a search result. One example of a word ladder with synonyms can be found below:

  1. Turkey
  2. Fry
  3. Oil
  4. Chicken
  5. Bird
  6. Fowl
  7. Boil
  8. Fat
  9. Yard
  10. Thanksgiving

The final part of coining search terms is simply adding words to the word ladder as the search progresses. A searcher can only think of some of the words that may have ever been used in the prior art. However, adding words to the word ladder and using those words to improve one's search often helps find more relevant results. While this means a searcher may have to refine and rerun a search a few times, it is often worth the effort. In the end, coining search terms is a bit like golf in that every time one hits the ball towards the hole (creates a word ladder and searches), they (hopefully) get a bit closer to their goal (a good search).

Step 2: Choose the Search Engine

The second step to conducting a patentability search is choosing which search engine will be used.

Google Patents

 Each search engine has its pros and cons, but one of the most common search engines, and one of the most accessible, is Google Patents. Google Patents has a basic search option as well as an advanced search option that allows the searcher to search for patents or patent publications by the following options:

  • Word or phrase
  • Priority date
  • Filing date
  • Publication date
  • Inventor
  • Assignee
  • Patent Office
  • Language
  • Status (grant or publication)
  • Patent type (design or utility)
  • Litigation history (has any or does not have any)

The most significant benefit of using Google Patents to search is that it is one of the most accessible search engines, especially if the searcher does not have much experience conducting patentability searches. However, it should be noted that Google Patents does not have 100% of all patents and publications, and the search result page may not be precisely what is in the physical copy of the patent or publication itself, especially for older references or those in other languages.


Another commonly used search engine is Espacenet. This search engine was created by the European Patent Office (EPO) and has similar ease of use to Google Patents. Like Google Patents, Espacenet has a basic search option as well as an advanced search option that allows searching by the following input categories:

  • Word or phrase
  • Publication date
  • Publication, application, or priority number
  • Applicant
  • Inventor
  • CPC or IPC code (codes assigned based on the subject of patent or publication)
  • Language of query

Espacenet, like Google Patents, draws its most significant benefit from its ease of use, especially if the user does not have much searching experience. However, these search engines' weaknesses are also similar, as Espacenet, like Google Patents, only has approximately 95-98% of all patents and publications. One potential solution to this is using Google Patents and Espacenet alongside each other, which would help cover the gaps in references each search engine has individually.

USPTO Patent Public Search

Some countries even have their own search sites, such as the USPTO's Patent Public Search. This site recently replaced and combined two of their old search sites, patFT and appFT. A searcher may prefer the Patent Public Search site if they are searching for references in the United States, as this is likely the most complete single search site for the US. However, this site only includes references from the US, as that is the only jurisdiction the USPTO covers. So, if a searcher needs to find references from other jurisdictions (such as China, the EPO, etc.), they will have to search on another site, either in combination with the Patent Public Search or in place of it.

Paid Software

Lastly, a searcher may choose to use any of a number of available paid searching software services. The benefits of this type of software can change depending on what company owns it but may include useful features that would not be found on the free search sites mentioned previously. While this could help a searcher find more results or precisely what they are looking for, that is not guaranteed, and they would likely need to pay for access to the software to find out.

No matter what option a searcher chooses, there are some imperfections that all search engines suffer from, and that will make it so a searcher will always miss something. It is essential to remember that the pure volume of references in the United States and worldwide means it is impossible to catch everything. Additionally, in the United States, there is an 18-month “blind spot” where a reference may have been filed with the patent office but has not yet been published, meaning that it is a reference that can be cited against a patent application, but there is no way to know about it until it publishes. Also, as previously mentioned, not every reference is included in every search engine. These issues are part of why any patent office worldwide will conduct its own search for references, so while a searcher may miss something, an examiner may be able to fill in any gaps.

How Gallium Law Can Help

            We know that searching through millions of patent applications, both in the United States and worldwide, can be confusing, especially if you have little experience, and that is why we are here to help. At Gallium Law, our IP professionals regularly handle all types of patent searches and can help you with everything from the first steps of a search to what to do with the information we find. We even have a few tricks to find additional references another searcher might miss. You may be a business or an individual; in either case, you deserve to know what IP is available to you, what you are up against, and to have someone by your side. Contact us today by filling out this online form or contacting us at 651-256-9480 to schedule a Free and Confidential Consultation.

*The information provided in this article is not legal advice and should not be relied on as such. This article is meant for informational purposes only and is intended as a starting point in your search for answers to your legal questions.

About the Author

Mike Bakke

Mike Bakke is a Registered Patent Agent at Gallium Law. Mike previously completed projects for Gallium Law as an independent contractor before being hired onto the team in 2023. While in graduate school, as well as during his time as an independent contractor, he also worked as a contractor at Sh...


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