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Search generates unexpected results.

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Symptoms: 

  • Searching two phrase terms using OR with the default search index as KW yields different results than using the Advanced search with each phrase term, and the OR Boolean selected.
  • Using quotes around the two phrase terms also unexpectedly yields more results.

Applies to

  • WorldCat Discovery

Answer

When a space is present, our system assumes "AND” whereas if the phrase is contained in quotes, we search the phrase as it is presented. We do not insert AND into the space between the terms. Our system also processes operators from left to right.

Here's how it works for two queries:

First Query: climate change OR global warming

  • Spaces are treated as AND, so the query becomes: climate AND change OR global AND warming.
  • The system processes from left to right:
    1. (kw:climate AND kw:change) grabs records containing both "climate" and "change".
    2. The result is combined with kw:global using OR, adding records with "global".
    3. Finally, the result is combined with kw:warming using AND, narrowing the results to records that also contain "warming".

Example:

  • Record One: Contains "climate change".
  • Record Two: Contains "global warming".
  • Result: Only Record Two is returned because "warming" is required in the final step.

Second Query: "climate change" OR "global warming"

  • Quotes instruct the system to search for exact phrases:
    1. "climate change" grabs records containing the full phrase.
    2. "global warming" grabs records containing the second full phrase.

Example:

  • Record One: Contains "climate change".
  • Record Two: Contains "global warming".
  • Result: Both Record One and Record Two are returned because the query matches exact phrases without additional filtering.

Key Difference:

  • The first query splits terms and applies logical operators, narrowing results based on specific combinations.
  • The second query matches exact phrases, broadening results to include all records containing the full phrases.

Using quotes around phrases in your search box ensures that only records containing those exact phrases are retrieved, making your search results more relevant and targeted. Without quotes, the search is much broader and may include less relevant results.

Additional information

See also: Search in WorldCat Discovery.

Page ID

66084