Ali Demirbaş - Lab
TRGet in touch

Product Detail Page

Size Chart or Personalized Size Advice A/B Test

A measurement chart asks shoppers to interpret the numbers themselves.

  • Product page
  • Size selection completion

Option A vs Option B

Two alternatives; neither is the incumbent.

Changed
Options
Page
Product page
Difference
changed

Hypothesis

A height-and-weight-based recommendation does some of that work, but adds data entry and may suggest the wrong size. Keep the chart available as a fallback; the comparison is chart-first versus recommendation-first help, not whether sizing help exists.

How to run this test

Primary metric

Size selection completion

Compare size selections per eligible assigned visitor, including visitors who do not finish the recommendation form.

Other metrics

  • Add-to-cart rateCheck whether the help format changes the first purchase step.
  • Size-related return rateTrack fit-related returns for orders that complete the same follow-up period.
  • Recommendation acceptance rateReport selection of the recommended size as a diagnostic measure in the recommendation arm.
  • Input form abandonmentTrack visitors who leave the height and weight form unfinished.

What to check before and during the test

  • Help formatCompare a size-chart-first experience with a recommendation-first experience that still provides access to the chart.
  • EvidenceKeep supporting claims and social proof unchanged.
  • InputsKeep input fields fixed and optional.
  • ModelValidate and hold the recommendation method constant for this comparison.
  • CategoryInclude only categories supported by the recommendation method.

Setup mistakes to avoid

  1. 1Do not present a low-confidence recommendation as certain.
  2. 2Do not require height or weight details to continue.
  3. 3Keep the standard size chart available as a fallback.
  4. 4Do not change size ranges alongside the help format.
  5. 5Do not launch an unsupported recommendation method.