Strengthen Your Research Potential with Boolean Basics

When working through any search on the internet, we all have our methods for searching databases. Some searches may be easy depending on the criteria or sometimes we may need to manipulate our keywords to get exactly (or as close as possible) to what we’re actually looking for. It can be frustrating and time-consuming.

But, is there a way to obtain more accurate search results faster most if not all of the time? YES! Let’s review the concept of Boolean.

What is Boolean?

George Boole invented Boolean Logic in the 1800s, well before computers.

The original purpose of Boolean was for logic, algebra, and probabilities. George Boole was the author of The Laws of Thought which laid the groundwork for what we know as the modern computer age.

Today, we know Boolean as a set of search commands that allows the searcher to combine keywords with operators (or modifiers) such as AND, NOT and OR to produce more relevant results. Boolean is the basis of all computer logic.

Understanding Boolean can be especially helping when researching genealogy or family history as you may use a specific name, a combination of name and location, or a combination of name, location, and date. Sometimes the results are spot on, sometimes not so much.

How Does It Work?


AND  The AND operator is inclusive and will limit your search to exactly what is before and after the AND.

Example: An AND search could be “John Smith” AND “Boston”. This would limit the search results to records that only contain those two keywords.

OR The OR operator will return a result with at least one search criteria is required. More than one or all can be returned and it may or may not return exactly what you are looking for.

Example: An OR search could be “J Smith” OR “John Smith”.

NOT The NOT operator is exclusive and will return results that do not include the criteria you’ve specified. 

Example: A NOT search could be “John Smith” NOT “Boston”. This would limit the search results to records that only contain those two keywords and would exclude anything with “Boston”.

Symbols and Modifiers

Quotation Marks ” “ – Quotation marks are required when searching for an exact phrase for more than one word. These must be used when searching for exact phrases of more than one word. When quotation marks are not used, search engines will split the phrase up into single word components which lead to a variety of search results that may not be relevant

Example: Search Term = John Smith will only return search results for exactly “John Smith”. Variations such as J Smith, Jon Smith, Jo Smith, etc. would not appear.

Parenthesis ( ) – Parenthesis combine modifiers to create a more complex search. 

Example: John Smith AND (Boston OR Massachusetts)

Asterisk * – When you use an asterisk at the end of a search term which may be an incomplete word, the search engine will return variations of how that word may appear.

Example: Search term = William* may return Williams or Williamson

Where Do These Boolean Techniques Work?

  1. Search Engines: Google, Bing, Yahoo, etc. By default, these search engines use the AND operator whether you specify it or not.
  2. Genealogy Research Databases: Ancestry, FamilySearch, etc. Their search tools actually give you button options that apply Boolean behind the scenes.
  3. Archive and media publication websites that contain a search box on their website.

Do You Need to be a Boolean Pro?

No, especially when researching on genealogy websites because sites like Ancestry and FamilySearch have made it easy for users at any skill level to use modifiers and operations when defining search criteria without even realizing it.

We know that when we can provide as much information as possible, we’re going to get more positive search results.

One example of how Ancestry applies Boolean for us is when we select boxes such as “match all terms exactly”. The search tool is applying the quotation marks modifier to each field completed.

Having inaccurate or too broad of search results can be frustrating and time-consuming. Try some of these Boolean basics when conducting online searches to see if helps you. You’ll be improving your searches in no time!