Web of Science

Using the Web of Science platform for new and experienced searchers.

Building a Search Strategy

Databases will often not understand your search if you enter it as a normal sentence, such as your full research question.

Instead, you'll want to brainstorm search terms that describe the concepts you are interested in to create a Search Strategy.

One method of developing your question into a set of concepts and terms that you can search is to use a concept map to help develop and focus your question and clarify your terms.

If you are asking a clinical question or conducting an evidence synthesis, try using the PICO structure or a similar model.

By connecting your search terms using Boolean Operators and Parentheses, you can tell the databases precisely how you want your search terms to be searched. 

Boolean Operators

Boolean operators let you connect your alternative terms and concepts together.

Be sure to type your Boolean operators in ALL CAPS. That lets the database know you're giving it a command. Otherwise, it ignores common words like and, or and not.


  • Limits your search to articles that contain both of the search terms
  • Narrows or focuses your search; you will typically get fewer results the more ANDs you use
  • Use AND between different concepts
  • For example: PFAS AND water
                         AND Boolean Diagram


  • Expands your search to articles that contain either of the search terms
  • Broadens your search; you will typically get more results the more ORs you use
  • Use OR between different search terms for the same concept
  • For example: PFAS OR PFAO OR teflon
                         OR Boolean Diagram


  • Excludes a term from your search
  • Narrows or focuses your search; you will typically get fewer results the more NOTs you use
  • For example: pig NOT guinea
  • BE CAREFUL!  It is very easy to exclude too much and accidentally miss important and relevant literature.
  • Try to use combinations of AND and OR, then exclude results yourself, instead of using the Boolean NOT
                         NOT Boolean Diagram


When creating a more complicated or advanced search, you can use parentheses to group your keywords together and tell the database precisely how you want the terms searched.  The database will perform the searches within parentheses before the searches outside of parentheses.  This is similar to the way parentheses are used in math.

Use parentheses any time you have more than one keyword for a particular concept.  In other words, when you are using the boolean operator OR, put parentheses around all of the OR'd terms.

For example:


digestive OR respiratory AND "harmful algal bloom*"

  • Looks for "respiratory AND harmful algal bloom*" first, then adds anything that includes "digestive"

(digestive OR respiratory) AND "harmful algal bloom*"

  • Omits irrelevant digestive results


Add Row

Instead of typing parentheses around the alternative terms for your concepts, you can use Web of Science's Add Row button to: 

  • Group your search terms into separate search boxes, connecting alternatives with OR.
  • Connect the search boxes with Boolean operators using the drop-down boxes.

Add a row to build your search


What is Truncation?

Truncation is a tool that is available in many databases, including those on Web of Science.  It allows you to easily search for all the different forms of a given root-word by adding the truncation symbol: * (asterisk)

For example, a search for pollut* retrieves pollution, pollutant, polluting, polluted, etc..

Things to Keep in Mind With Truncation

  • Think carefully about where you are cutting your word.  You want it to be broad enough to capture all the relevant forms of the word, but also not so broad that it floods your results with irrelevant items.
  • What are the forms you are hoping to capture?  You should have a rough list in your head of what you are expecting to find with the truncated term.
  • Are there forms you do not want to capture?  For example, if you truncate child* to retrieve child, children, and childhood, you will also capture articles talking about childbirth, childless, childish, and childrearing.  In this case, it might make more sense to spell out all the forms that you want.

Phrase Searching

What is Phrase Searching?

If you are using a multi-word search term in your search, such as species diversity, you will want to think about how important it is that they stay together in order to still be relevant. 

If you want the terms to stay together and in the order you put them into the search box, you can put them into quotation marks to search them as a phrase.  "Species diversity" retrieves only articles that talk about species diversity as a concept, rather than mentioning the word species in one place and the word diversity in another.

Things to Keep in Mind With Phrase Searching

  • Think carefully about how your terms might realistically appear in the literature.  Approach this step with an open mind.  You don't want to search with a lot of long and complex phrases that may not occur exactly as you entered them very often.  This will make your search too narrow, and you will potentially miss relevant articles.
  • You also do not necessarily want to allow all of your search terms to be split apart, as some may need to stay together to stay relevant.
  • Web of Science allows the use of Proximity Operators using the Advanced Search Query Builder.  These are tools that allow you to tell the database that the terms need to appear within a certain number of spaces from each other, which allows you to search for concepts that are phrased in a number of similar ways.  This takes the format of term1 NEAR/# term2, where # is the maximum number of words that can appear between your terms.