How can you use wildcards to find variations of a search term in Boolean searching?

1 What are wildcards?

Wildcards are symbols that can stand for any character or group of characters in a search term. They are often used to find words that have different endings, such as plurals, verb tenses, or suffixes. For example, if you want to search for books or booklets, you can use the wildcard * to replace any number of characters after the word book. The search term would be book*, and it would match any word that starts with book, such as books, booklet, bookshelf, or bookworm.

2 Types of wildcards

Different search engines and databases may use different symbols for wildcards, but the most common ones are * and ?. The asterisk (*) can replace any number of characters, while the question mark (?) can replace only one character. For example, if you want to search for words that have the same root but different prefixes, such as preheat, reheat, or overheat, you can use the wildcard ? to replace the first letter. The search term would be ?heat, and it would match any word that has four letters and ends with heat, such as beat, heat, meat, or neat.

3 How to use wildcards in Boolean searching

To use wildcards in Boolean searching, you need to combine them with other keywords and operators, such as AND, OR, or NOT. These operators help you narrow or broaden your search results by specifying the relationship between the keywords. For example, if you want to search for articles about climate change or global warming, you can use the wildcard * and the operator OR to find both terms. The search term would be climate change OR global warm*, and it would match any article that contains either climate change or any word that starts with global warm, such as global warming, global warmed, or global warmer.

4 Tips for using wildcards

Wildcards can be useful to find variations of a search term, but they can also cause issues if not used correctly. To avoid common mistakes, use wildcards sparingly and strategically. Consider where you want to place the wildcard and how many characters you want to replace. Additionally, combine wildcards with other operators, such as AND, OR, or NOT, to filter results and find more relevant information. For example, if you want to search for articles about cats or dogs but not animals in general, use the wildcard * and the operator NOT to exclude the term animal. The search term would be cat* OR dog* NOT animal, which would match any article containing either cat or dog or any word starting with cat or dog but not the word animal.

5 Examples of wildcards in Boolean searching

Wildcards can be used in Boolean searching to yield specific results. For instance, a search term of "comput* AND (artificial intelligence OR machine learning)" will return articles that contain the word computer or any word that starts with comput, such as computing, computerized, or computational, and either artificial intelligence or machine learning. Similarly, a search term of "wom?n OR (gender AND equality)" will return articles that contain the word woman or women, or both gender and equality. Finally, a search term of "(health* OR wellness) AND (diet* OR nutrition)" will return articles that contain either health or wellness, or any word that starts with health or well, such as healthy, healthful, wellbeing, or wellnesses, and either diet or nutrition, or any word that starts with diet, such as dietary, dietetic, or dieting.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?