Prior Art Search: A Short Guide

March 1, 2024

The term “prior art” is central to patents, influencing numerous aspects of intellectual property.

Its existence significantly impacts which innovations are granted patent protection, which patents are deemed valid and enforceable, or whether a business can safely launch a product or enter a new market without risking infringement, and so on.

This guide discusses prior art and the prior art search process, and their crucial role in an effective IP strategy.

What is prior art?

The term “prior art” refers to any publicly available information, which includes patents, patent applications, scientific literature, technical publications, product manuals, and other technology disclosures that describe similar or related inventions or technologies.

In the United States, the legal definition of prior art is set out in 35 U.S.C. § 102, which defines prior art as public disclosures that are “patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.”

What is a prior art search?

A prior art search is a process that involves searching for and examining existing publicly available information to determine if an invention is novel and non-obvious.
The goal of a prior art search is to uncover relevant technology disclosures that predate an invention, or in the context of patents, the effective filing date of the claimed invention.
Prior art is important in determining the patentability of an invention, validity of a patent, and can potentially impact the ability of a business to bring its products and services to market.

Why conduct a prior art search?

In the different stages of the innovation cycle, a prior art search may be conducted to serve various purposes:

Assess novelty and non-obviousness of an invention
Guide R&D direction
Invalidate the claims of an asserted or blocking patent
Evaluate the strength and enforceability of a patent before licensing or investing
Determine if a product or service infringes on existing patents in a given jurisdiction
Gain insights regarding the existing technologies and patented inventions within a technology area

What are the types of prior art search?

Depending on the specific objectives, prior art searches can be categorized into four distinct types, each serving a different purpose:

Patent Invalidity Search

A patent validity or patent invalidity search is conducted to assess the validity and therefore, the enforceability of an existing patent. One of most common reasons for conducting this type of prior art search is in aid of patent litigation or in the event of a patent infringement suit.

Patent Litigation and Post Grant Proceedings

In a patent infringement suit, a defendant may choose to declare non-infringement. Another course of action is to invalidate the claims of the asserted patent. In order to invalidate the claims of a patent, there must be evidence of prior art.

Apart from patent litigation in federal courts, the defendant may opt to use the patent invalidation mechanisms provided by the USPTO such as the inter partes review and post grant review, among others. These post grant proceedings are held before the Patent Trial and Appeal Board (PTAB) and may offer a faster and cheaper resolution compared to costly patent litigation.

Regardless of where a defendant chooses to litigate, there must be a thorough prior art or patent invalidity search conducted to prove that there is prior art.

Patent Licensing and IP Strategy

A comprehensive patent validity search is a crucial component of of a well-informed IP strategy.

Before acquiring or licensing a patent, the buyer or licensee must make sure that the patent claims are indeed valid in view of the prior art to avoid potential legal risks
As a risk management tool, a prior art search can assess the strength of a patent. Can it withstand patent challenges before the courts and other proceedings? This is an important step before a patent holder decides to enforce their patent and engage in patent litigation.

Patentability Search

A patentability search, also known as a novelty search, is conducted to identify any prior inventions, publications, or other publicly available information that may be relevant to the invention.

Though this type of search is not a predictor for patentability, it can help a patent attorney evaluate the likelihood of obtaining a patent and provide a patentability opinion. This type of search aims to identify prior art that could potentially hinder the grant of a patent due to lack of novelty or non-obviousness.

A patentability search is a complete must before filing a patent application. It offers valuable insights to strengthen the drafting of the patent application, provide ideas for design-around, etc. It is ideal to conduct this type of prior art search even at the early stages of ideation, allowing for a more informed decision regarding R&D direction.

Freedom to Operate Search

A freedom to operate (FTO) search, also called a “clearance search” is conducted before introducing a new product or service to the market. This search identifies existing patents and other intellectual property rights that may potentially be infringed by the new product or service.

As patent rights are territorial, this type of prior art search is important before entering a new region or market.

The main focus of this prior art search is to determine if there are existing patents in a given jurisdiction that disclose the same elements as the new product or service.

A freedom to operate search will be the basis for a freedom to operate opinion that will be provided by a patent attorney.

State of the Art Search

A State of the Art (SOA) search, also called a Collection search, is conducted to assess the existing technical advancements in a particular field. It identifies prior art relating to a certain technology which provides insights regarding the patentability of an invention, infringement risks, evaluation of the inventive step, among others.

This wider scope of a prior art search not only identifies technologies that are similar to your idea or invention, but also “competing art” which are technologies that solve the same problem but in a different way.

How do I conduct a prior art search?

Here’s a basic framework for conducting a prior art search.

Define the invention and set the scope.
Every prior art search starts with a thorough understanding of the essential features or the “inventive concept” of the subject matter or claimed invention. Define the “effective filing date” of the invention. This forms the basis of your search criteria.
Identify keywords and classifications.
Build a list of keywords and keyword strings associated with the invention. Apart from text searching, patent classification codes (CPC or IPC) can improve the precision of the search and narrow down your pool of results.
Use patent search databases.
Utilize reputable, publicly available patent databases such as Google Patents, Espacenet and the USPTO. For non-patent literature searching, include academic journals, and conference proceedings etc.There are also patent search tools that use AI and machine learning to perform prior art search. One AI-powered patent search tool is PQAI or Patent Quality Artificial Intelligence. It is an open source, non-profit initiative by AT&T and the Georgia Intellectual Property Alliance.
Optimize and analyze results.
A prior art search is an iterative process, and requires continuous optimization. Refine search queries based on your initial results. Combine various search strategies, e.g. keywords search + CPC.
Keep detailed records of relevant references.
A typical prior art search report will include a claims mapping or technical mapping chart which maps the claims of a patent or the elements of an invention to the references found. Download a sample report here.
Get a patent search provider.
As a comprehensive prior art search can be a daunting task, enlisting the help of patent research professionals can also be beneficial. Find a research partner that understands both the legal and technical aspects of a prior art search, and has a proven track record in providing quality results.

Book a consultation

What our clients are saying

“The first search Parola Analytics, Inc. performed for us provided the key reference supporting our invalidity position on a patent we were evaluating.”

Sean M. Dean, Ph.D.

Fish & Richardson

“Vincent and his team at Parola are excellent at locating prior art. We have worked with Parola on two matters, and both times, Parola delivered outstanding results. Parola’s highly-relevant search results and reports demonstrated a thorough understanding of the patent claims.”

Daniel Kiang

Knobbe Martens

“Vincent Violago and his excellent team at Parola Analytics provide high quality, detailed, prior art search results with minimal oversight and handholding. These guys are highly educated and experienced in their field and work together with great efficiency. The work product is top-notch, and they are always available for follow up, including detailed discussions of the report and additional pinpoint searches based on the results. I highly recommend Vincent and his team.”

James A. “Tripp” Fussell III

Mayer Brown

"Parola analysts uncovered prior art that even opposing counsel’s team could not during litigation. The quality of their work and deeper understanding of the subject matter were instrumental to the case that we eventually won.”

Saqib J. Siddiqui

Mayer Brown

“The team at Parola Analytics did an excellent job in providing us with the highest-quality prior art research service.

The team’s search report highlighted the best prior art references with an easy-to-understand format. In short, the team proved itself.”

Ryan Phelan

Marshall, Gerstein & Borun LLP

“I recently engaged Parola Analytics to conduct a prior art search on a difficult US patent that had already stymied another search firm that delivered two unusable references.

Parola found four much better references in two weeks that demonstrated a deeper understanding of the search and an effective selection of the best references.

I highly recommend Parola Analytics.”

Barry Shelton

Shelton Coburn

“Parola Analytics is our trusted partner for prior art search contests on PATROLL, Unified Patent’s crowdsourcing platform.

With their expertise in prior art searching, Vincent and his team at Parola Analytics are valuable partners in reviewing prior art submissions to our contests.

Parola Analytics provides broad knowledge across various subject-matters and offers competitive pricing.

They are easy to work with and are responsive to our needs.”

Sam Jaffna

Unified Patents

“In just weeks, our investments in our relationship with Parola Analytics started to pay handsome dividends. Parola Analytics identified a patent filed by researchers at Yale that showed promise as a vaccine against malaria. Our article, authored by Monisha Ravisetti, was publicized in hundreds of newspapers and magazines worldwide and quoted thousands of times on social media. Parola’s flexibility proved invaluable for a startup company like ours, and the reasonable fee structures allowed us to invest in the relationship with confidence.

Marius Meland

Founder, Law360

CEO and Founder, Fastinform

“Parola Analytics has consistently provided excellent search results coupled with an easy to navigate and detailed search report. Parola’s responsiveness and communication are exceptional. I highly recommend Parola.”

Chris Hadley

Jones Waldo

“Parola Analytics is an outstanding resource for our boutique intellectual property firm. Patentability searches are the first step for new patent clients. Vincent and his team take care of this crucial step, and provide us with high-quality and comprehensive search reports. The search reports provide our clients with a clear visual representation of the state-of-the-art and make our counseling even more impactful. Our patent practice is enhanced by Parola Analytics’ search capabilities, and our favorite find is Parola Analytics.”

Justin H. Cross

HamiltonCross LLP

“Parola Analytics was able to quickly provide us with a key prior art reference despite other search vendors failing to find anything useful. Parola’s thorough search report also provided detailed analysis and allowed us to easily assess the viability of the references and efficiently create invalidity contentions. Would highly recommend.”

Luc Dahlin

Goodwin Procter

“It was an absolute pleasure working with Parola Analytics. Vincent Violago is very responsive and professional. He answers all your questions and ensures the right person does the search. The patentability report provided is very visually pleasing and easy to follow.

The searcher (who is a PhD chemist and registered US Patent Agent) took great care to understand the claim language of a biotech invention prior to doing the search. A very thorough search was done in a timely and efficient manner. I highly recommend Parola Analytics for patentability searches.”

Imtiaz Billah

Torrey Pines Law Group PC

“Parola Analytics is the perfect fit for us, start-ups. They offered us the flexibility we needed for our unique needs. We received high quality results fast at competitive prices.”

Alfredo Carranza

i6 Technology

“We commissioned Parola Analytics for a patent invalidity search. Within a couple of weeks, Parola provided useful prior art references along with an easy to digest report explaining how the references related to each limitation of the relevant patent claim in our case.”

Michael Rhodes

Desmarais LLP

I am delighted to wholeheartedly recommend Parola Analytics for patentability searches. For a recent project I had done by Vincent and his team, Parola Analytics delivered timely work product that was second to none. The search was clearly thorough, and was laid out in a professional, easy to understand and comprehend format complete with excellent graphics, summaries, and in-depth details that enabled me to quickly ascertain my client’s position for patentability. Thank you Parola Analytics! I’ll definitely use your outstanding, cost-effective services going forward!

Tom LaGrandeur, Ph.D., J.D.

P and T Law

For small IP firms looking for a reliable patent research partner, Parola is the perfect choice. Parola Analytics has consistently delivered high-quality results in the various patentability and design patentability projects we have worked on. They have a very collaborative and hands-on approach to each project. The researchers have vast experience and IP knowledge which allows me to get results well-aligned with my specifications.

Tom Tatonetti

Tatonetti IP

“Thank you again for providing the patentability search and report. The report was very thorough, and easy to follow. Also, it appears your standard pricing is competitive and reasonable compared to other searching firms I have engaged.”

DJ Tucker

Harness, Dickey & Pierce

image of a Caucasian man in business attire

.We’ve been very pleased with Parola’s search results. They’ve proven themselves to be reliable, responsive, and effective.

Nick Boyarski

Hatch Patents

"The best features of Parola Analytics are the responsiveness, enthusiasm and hands on service they deliver. I intend to use their service on my next search task. Thanks Parola Analytics."

Chris Novak

MoSys, Inc.

"Parola Analytics performed a quality prior art search with a quick turnaround for us."

Kumar Ravula, JD, PhD

Latham & Watkins, LLP

"Parola Analytics provided exactly what we needed for our patentability search. They quickly were able to get to the core of the search and provided an easy to understand report for both attorney and client. They are my first call for my searching needs."

Shawn Diedtrich

Prudens Law LLC

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