Reading a cosmetic trial and its photographs
A split-face design helps identify the comparison within each participant.
Use the reported comparison without broadening its scope.
A split-face design helps identify the comparison within each participant.
A historical example
Robinson and colleagues studied 93 women aged 35–55, described in the paper as Caucasian, for 12 weeks. They compared a pal-KTTKS cream with its base on randomized sides of the face and reported improvement in lines and wrinkles. The population and formula bound the result; it should not become a percentage of “rejuvenation.”
A short checklist for the image
Look for which side received each product, how assessors were masked and which scale was used. Check whether photographs represent the same interval and whether the analysis includes the intended participants. This is an editorial aid: selected photographs alone cannot reconstruct the complete result.
Professional context / Contexto profesional
The authors reported Procter & Gamble affiliations; retain that context and review the full text.
Evidence / Evidencia
Randomized split-face cosmetic trial.
Limitations / Limitaciones
Historical reading based on the article record and abstract, without an invented effect size.