A Primer on Boolean Logic

NLPatent’s AI-first approach is a marked improvement over traditional patent search methods, making the process more efficient, accessible, and user-friendly. However, traditional keyword searches and filters can still be extremely powerful in the right circumstances which is why NLPatent supports both AI and keyword searching! This guide will focus on how Boolean logic works, if you are searching how to apply boolean filters in NLPatent see this article instead. 

An Introduction to Boolean Logic

Boolean logic lies at the heart of keyword searching. Using a limited set of operators, boolean logic allows one to construct keyword queries that target results with very specific criteria.

Operators in Boolean logic are symbols or words that connect statements, dictating their relationship. These operators refine search results by logically combining or excluding keywords. Common operators include: 

• AND: Which requires both connected statements to be true
• OR: Which requires at least one to be true
• NOT: Which excludes statements containing specified terms. 

Keywords are used to build Statements. A keyword is either a word or a phrase that you want to search for, such as ‘microchip’ or ‘semiconductor’. A statement combines a keyword and a condition, which is evaluated to be either True or False. In patent searches, a statement might be: 

• ‘Title' contains 'microchip'
• 'Description' must have the phrase 'silicon' within 3 words of 'semiconductor'

These statements are the building blocks of a Boolean search query, guiding the search engine in filtering results.

A Boolean expression combines statements and operators to define a search query's logical condition. Parentheses can group statements, controlling the order of evaluation, much like in mathematics. This structure allows for complex and precise searches to be executed by clearly defining how different conditions should be combined and prioritised.

Boolean expressions are evaluated by determining the True or False values of individual statements and then logically combining these values using operators. For instance, if the expression:

• 'Abstract' contains 'silicon' OR 'Abstract' contains 'semiconductor'

If the 'silicon' statement is False and 'semiconductor' statement is True, the boolean expression would evaluate to True.

Conclusion

Although pure keyword searching has its limitations, it has its advantages as it looks for specific terms of art. Below, you will find example questions to help you become more familiar with the process. For detailed guidance on building filters within NLPatent, refer to our Creating Keyword Filters article.