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By J.D. Houvener
Patent Attorney and Founder

The best place to start here is defining what this whacky phrase “prior art” means. I’m guessing that if you found this article from a search engine, and you actually typed in “prior art,” you are sophisticated enough to have some idea. 

So, for the benefit of those who may not know (or should know), let me lay it out there.

“Prior Art” means any publication containing all or part of your invention that was released to the public prior to the priority filing date with the USPTO.

Let’s break that down just a little, shall we? 

“Publication” in this sense is just that: any newspaper, online repository, journal, academic writing, Kickstarter/Wefundr/Gofundme, Facebook, or even old school printed books/media. And even beyond that, we’re talking about ALL languages and ALL time/history. 

Yeah, I know, let that sink in a bit… Imagine a printed newspaper article in a foreign language somewhere in Eastern Europe – you (or as I’ll recommend below, your attorney) had better find it before investing your time/money in the patent application process.

Remember, the goal of the patent process and the examination at the United States Patent and Trademark Office (USPTO) is to assure that only inventions that are TRULY NOVEL get awarded. This means that the claimed invention cannot have ever been published/discussed/disclosed before at any time in history. 

A KEY distinction here is that “prior art” is a more general term which covers any publication, including both patent and non-patent literature. 

A less-generic term, although often not meant to be specific, is called a “prior art search”. Now, if you ask the right questions, you can see whether the search is really only for patents or if it covers non-patent literature/publications as well. 

Now, all this upfront business about how to define prior art… and we haven’t even gotten to the six steps yet??? I know. Well, the reason is that the steps for a prior art search and “prior patent search” are the SAME (at least at Bold Patents). Therefore, the blog article I wrote on “How to do a patent search in 6 Steps” will have the SAME essence as this 6 step article. 

Step 1: Understand what a Prior Art Search IS and what it is Not

Step 2: Invention Disclosure

Step 3: Identify 3-5 Key (New) Features

Step 4: Non-Patent Publications Search

Step 5: Patent Publications Search

Step 6: Non-Traditional Searches

Bonus Step: Value of a Legal Opinion

Step 1: Understanding what a Prior Art search is and what it is not

It’s important to know what your goals are before going into a prior art search. It’s best to set expectations properly at the onset so you’re not disappointed or confused when you are finished.

A prior art search is just one piece to the puzzle.

The goal of the prior art search is to inform you, the inventor, about patentability. Patentability is the bigger, more important question that will need to be answered using the results of the prior art search.

The prior art search informs a Patent Attorney to help them provide you, the inventor, a LEGAL OPINION as to the potential rights that may be achieved if a patent application were sought.

Lastly, it is with the Legal Opinion that you can then form a BUSINESS DECISION as to whether the risk of investment into the patent application will be worth it.

Here is the REQUIRED process for getting to Patentability:


You can have the most patentable invention in the world, but it may be the worst idea ever commercially and, therefore, the inventor will not see success in the end.

Therefore, it is critical to assess the market prior to investing money into any venture, especially one as time and capital-intensive as the patent process.

Here is the REQUIRED process for getting to Marketability:


Last but not least, the formula for making the best business decision is, therefore, following a Patent Success Matrix that looks at both Patentability and Marketability as follows:


For additional information about Patentability and Marketability, you can read in-depth details about the Patent Success Matrix in Steps 6 and 7 when you learn how to patent an idea.

Now that you know what a prior art search is, and where the prior art search fits in the broad picture–it will help you understand where the information gathered in the search phase will be used for the next step.

Step 2: Invention Disclosure

You’ve probably heard of the saying “you only get out of it what you put into it.” Without a doubt, that is true here.

Your Patent Attorney should understand the invention as well as you do before they conduct the search or opine on the results.

Hold absolutely NOTHING back here. Tell your Patent Attorney everything you’ve ever conceived relative to this new invention, including how you plan to use it or monetize it.

A good Patent Attorney will tease out the entire invention (and then some) by asking questions, seeking more information about certain aspects, functionality, or applications.

At Bold Patents we use an Invention Disclosure Form (IDF) form which goes through many questions about the invention itself, and gets the inventor thinking about alternative embodiments or versions that may not be implementable due to cost, but are achievable if money were no barrier.

A generically described invention that has only loosely described structure and ambiguous functionality and features will return a search result that is only surface-level. This is very difficult to discern when it comes time to form a legal opinion on it.

A well-defined invention, on the other hand, is much more straight-forward to search on and allows the Patent Attorney to do a deep dive search on the subject.

There is no doubt that inventions change over the course of representation with many clients, especially after an application is submitted and customers finally are able to give their feedback on a device/system.

Hence, a subsequent search is often necessary to assure that the improvements/changes in the invention are patentable. The process is the same as it will be described here.Of course, the subsequent search will stand on the shoulders of the previous search, and so the higher quality the initial prior art search, the better results for all future improvements of what will hopefully become a patent portfolio.

Step 3: Identify 3-5 Key (New) Features

Once the invention has been sufficiently disclosed, it can be boiled down to a small set of key features. The features can also be seen as functions.

What are the core features of the invention?

The quantity of features does vary invention to invention, but I usually find a way to narrow down the core set of features to fewer than 5 (five) distinct features.

The reason for spending time identifying key features is to make sure that we cover all aspects of the invention, without duplicating effort.

Each major feature will require a separate search inquiry to make sure that we cast a wide enough net. But what’s nice is that we have a defined limit as to how many nets we cast, and into what water.

When identifying features, do not try to get too fancy. Use natural language and simply describe the important features of the invention. You can use complete sentences as needed to fully identify each key feature, so there’s no limitation.

Example of Features:

Feature 1: Straight Edge Cutting Guide with Slit

Feature 2: Class two lever (alligator style) Cutting Device

Feature 3: Height Adjustable Cutting Device

Each major feature of this cutting device is identified in plain terms without going into too much detail. The goal is to guide the search without directing it.

Step 4: Search Broadly

For each of the defined key features, conduct a Google prior art search, which is the best natural language search on the planet.

From here, you can do a prior art search by date, a prior art search by inventor, a US prior art search, or a prior art search outside of the US.

This is a really cool developed by Google for you! Click here to check out Google’s prior art search! 

You will want to check the box “Include non-patent literature” which will include journals, academic dissertations, thesis papers, newspapers, or other reports from around the world.

You may need to wade through several pages of results before you find a patent document with a disclosure that is similar to your feature.

This is a lengthy process and cannot be rushed. Spend no less than 4 hours with this initial phase of research, where each major feature of your invention gets a dedicated natural language search.

Here is an example search:

As you do a Google prior art search, and use different natural language keywords and phrases, make sure to use the Boolean search strings to aid in refining searches to help you hone in on the feature of interest.

Here is a table of Boolean searches:

The goal is to find publications (patent documents or non-patent literature documents) that have at least one of the features and functionalities of your invention so that you can hone-in on the best classification of your invention.

Step 5: Patent Publications Search

The best way to find patent documents that are similar to your invention is to search within the proper patent classification. There are many different patent classification systems out there, so you will need to become familiar with them as you start to gather information on inventions that are similar to your invention.

There are hundreds of classifications – but it will become critical to determine which classes your invention falls into to assure you’re researching the correct publications.

Here is an exhaustive list of classes numbered 0-1000 available on the USPTO website.

To keep things straightforward, I will only talk about the US classification system.

So, when looking at US patents, you can spot which class each patent is in from the first page of the patent. See red circle below:

Here, you can see the “U.S. Cl” which means “United States Classification” is “83.” There are a lot of sub-classes, but 83 is the major class, which is defined by the USPTO as follows:

Class 83 is the residual locus of patents directed to methods and machines for penetrating material, without substantial reshaping flow of such material, by means of (1) a solid tool, or fluid current, either of which applies mechanical deforming force to the material by direct physical contact therewith, the fluid current forcing the material against a solid tool whose edge defines the line of cut; (2) a heated solid tool which directly engages the material (to effect penetration thereof by melting, or by transmission of mechanical energy, or both); or (3) opposed, controlled fluid currents.

After you’ve confirmed that for each distinct feature or functionality of your invention you’ve got the correct classification, you need to find the correct sub-classification(s) for your invention.

By identifying sub-classifications, you will be able to refine your search to a manageable number of patent documents.

Sub-class research will allow you to find a close brother/sister invention and then continue drilling down into the details of similar publications by following which patents the examiner cited as being similar.

When you stumble upon a patent publication of an invention similar to yours, that invention had to have been examined at the USPTO.

The examiner did their best search to see what they could find in terms of prior art. So that means you can leverage the hard work of that expert examiner. Use references and citations that points to their work.

Here is a look back to our example – I’d start by researching the most recent references first:

Don’t forget that this process of classification will not be useful for non-patent documents/publications.

We will need to have an equally robust way of reviewing non-patent literature.

Step 6: Non-Traditional Searches

Once the broad search is complete, it is very important to conduct searches in other search engines that may have access to domestic and foreign patent publications that Google may not.

Here is a list of websites to conduct your searches. The list serves as an example list, and is not exhaustive in any way:

Best Country-Specific Natural Language Searches

Click on any of the links below to be taken to that particular website.

  1. United State prior art search
  2. British prior art search
  3. French prior art search
  4. German prior art search
  5. Chinese prior art search
  6. Japanese prior art search
  7. Korean prior art search


Click on any of the links below to be taken to the multi-country website.

  1. European Patent Office (EU) “Espacenet”
  2. World Intellectual Property Organization (WIPO) “Patent Scope”
  3. Patent Lens

Do not rely on just a Google prior art search to do the searching for your inventions.

You need to assure you turn over every rock and seek out the best information possible. To do this, go to the websites above and perform distinct searches for each key feature and functionality.

After you’ve completed steps 1-6, congratulate yourself!

Bonus Step

You’ve put in hard work and gathered a substantial amount of research, and are now well informed about the invention and the technology area that the invention is in.

However, despite having all of this knowledge, you may be asking:

“Ok, so I have all of these patents and non-patent documents, now what?”

Well, to do it right, you will now need to analyze the results to decide which references are closest to yours.

The kind of analysis needed here is legal.

Yes, anyone can do it, but it will require a deep understanding of the statutory rules around patent law (35 USC 101, 102, and 103) and the lengthy case law history as it has evolved through the district, appeal, and supreme courts over the years.

If you want us to help you click here to book a free consultation! (Free Inventor’s Guide to Patents Book Included!) 

In Conclusion:

As I am sure you experienced as you read this article…

…getting a prior art search can be a pretty daunting process.

It’s not very glamorous, it’s not as exciting as the process of how to get a patent for an idea, and it requires digging through hundreds if not thousands of publications to assess the merits of an invention.

However, if you follow these 6-steps it can make it a bit less stressful:

  • Step 1: Understand what a prior art search is and what it is not
  • Step 2: Invention Disclosure
  • Step 3: Identify 3-5 Key Features
  • Step 4: Begin Seraching Broadly
  • Step 5: Determine Invention Classification(s)
  • Step 6: Non-Google prior art searches
  • Bonus Step: Get a Legal Opinion

What do you think? Any additional tips or questions you have? 

Please let me know in the comments below!

Want additional help?! Click here to book a free consultation today! 

Legal Note: This blog article does not constitute as legal advice. Although the article was written by a licensed USPTO patent attorney there are many factors and complexities that come into patenting an idea. We recommend you consult a lawyer if you want legal advice for your particular situation. No attorney-client or confidential relationship exists by simply reading and applying the steps stated in this blog article.


About the Author
J.D. Houvener is a Registered USPTO Patent Attorney who has a strong interest in helping entrepreneurs and businesses thrive. J.D. leverages his technical background in engineering and experience in the aerospace industry to provide businesses with a unique perspective on their patent needs. He works with clients who are serious about investing in their intellectual assets and provides counsel on how to capitalize their patents in the market. If you have any questions regarding this article or patents in general, consider contacting J.D. at