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ACM Digital Library

Search Operators

  • You can use Boolean AND, OR and NOT to connect your search terms (see Search Techniques in our searching guide)
  • You can also use parentheses, which can be used to group terms and operators as required (see Compiling a search string in our searching guide)
  • Boolean operators must be capitalised; if they are not capitalised they will be interpreted as search terms 
  • An AND relationship is automatically assumed across multiple rows
  • An OR relationship is automatically assumed across multiple terms in each row
  • It is recommended that you manually connect multiple terms on a row using OR to ensure accuracy, as relying on the assumed relationship can impact the number and relevance of your results.

Example:

Screenshot of advanced search in ACM Digital Library. Two search strings (detailed below) with "Anywhere" field selected.

Row 1: "machine learning" OR "artificial intelligence" OR "neural networks"
Row 2: "cyber crime" OR "computer crime" OR "cybercrime"

Proximity Search

In ACM Digital Library, proximity searching allows you to return results with two or more terms with a specified number of words between them.

  • Place quotation marks around the phrase (e.g., "machine learning").
  • Add a tilde (~) followed by a number to indicate the maximum number of words between the terms (e.g., "machine learning"~10).

The example "machine learning"~10 will find results where "machine" and "learning" have up to 10 words between them.

Wildcards

By default, ACM Digital Library search is configured to use plurals and stemming (retrieving variations of a keyword that use the same root or stem). Wildcards should be used when you need to include variations that stemming might miss, such as irregular forms, different prefixes or suffixes, and alternative spellings. They also allow for enhanced customisation and precision, which is particularly useful when searching systematically. 

  • Use an asterisk (*) to indicate any number of characters (e.g., compute* returns compute, computer, computers, computed
  • Use a question mark (?) to indicate one unknown character (e.g., compute? returns compute, computer and computed
  • A tilde (~) can be appended to a word where multiple spellings may exist (e.g., program~ returns program and programme

Please note the following limitations:

  • Using wildcards at the beginning of a term will cause an error.
  • Wildcards are ignored when performing phrase searches (e.g., "machine learn*").

Phrase Search

By default, search is configured to use plurals and stemming (retrieving variations of a keyword that use the same root or stem). Therefore, phrase searching should be utilised wherever you require to interpret any single word or phrase literally. 

  • Enclose search term(s) in double quotation marks (" ") to search for an exact word or phrase 
  • Single quotation marks (' ') are ignored 
  • If no quotation marks are used an OR relationship will be assumed between words 

Example:

"machine learning" returns results with the exact phrase (146,995 results)

Screenshot of search query and number of results (146995) when phrase searched

machine learning returns results with machine OR learning (240,336 results)

Screenshot of search query and number of results (240336) when not phrase searched

Relevance Boost

  • By default, search results are ranked by relevance (see Viewing Results to sort results by date, citation or download count).
  • Terms found in the keyword, title, abstract, or author fields are automatically assigned higher relevance.
  • You can increase the importance of a term in a multi-term query by adjusting its boost factor.
  • The default boost factor is 1.
  • To increase a term's boost factor, use the caret symbol (^) followed by a number (e.g., computing AI^5 makes the term "AI" five times more relevant than "computing")