Ali Demirbaş - Lab
TRGet in touch

Search & Filtering

Highlighting the Search Term in Results: A/B Test Idea

Highlighting matching words may help visitors understand why a result appeared.

  • Search
  • Product page visit rate

Control vs Variant

How hard the same message is pushed is the variable.

Changed
Emphasis
Page
Search
Difference
added

Hypothesis

Too much highlighting can make titles harder to scan, while highlighting a weak match may expose poor relevance. Keep matching and ranking fixed and change only the highlighting.

How to run this test

Primary metric

Product page visit rate

Compare product-page visits per eligible assigned visitor who sees the same search results; clicks alone do not prove the right product was found.

Other metrics

  • Purchase conversion rate (CR)Compare purchases among all eligible assigned visitors over the same follow-up period.
  • New query rateCompare visitors who submit another query after seeing results, using the same results-impression denominator.
  • Search-results exit rateCompare exits among visitors assigned on the search-results page.

What to check before and during the test

  • HighlightUse one fixed, accessible style to mark query-matching words in result titles.
  • DensitySet how multiple matches are shown and check that titles remain readable.
  • ScopeHighlight titles only; highlighting descriptions is a separate test.
  • RelevanceReview weak matches without changing ranking during the test.
  • Device and queryCheck truncated mobile titles and predefined query-length groups.

Setup mistakes to avoid

  1. 1Do not rely on color alone; maintain sufficient contrast and another visible cue.
  2. 2Do not change highlighting and result ranking together.
  3. 3Avoid broad matching that highlights most of a title.
  4. 4Do not use highlighting as a substitute for improving poor search relevance.
  5. 5Do not generalize from single-word queries to long queries.