Case lab: conflicting brightening evidence
Three marketing decks claim the same pigment benefit using different endpoints. Build a clear judgement and decide what further experiment you would ask for.
The hypothetical datasets
Study A: twelve users, two weeks, photographs taken in changing light, claimed '45% brighter'. Study B: 160 randomised users over twelve weeks, matching control, validated pigmentation score difference of 6 points on a 100-point scale with a narrow interval. Study C: forty users over eight weeks, no control, favourable self-reports but no colour measurement. These invented numbers are for decision practice, not published product data.
Case lab: conflicting brightening evidence — a published visual reference for the topic, not SESH product-test data.
Open full-size image ↗Define which claim is being tested
'More radiant' may capture overall light reflection or moisturised appearance; reduced dark-spot pigmentation should be measured in the affected patches using standard conditions. Do not use overall glow to prove melasma improvement. Separate post-inflammatory hyperpigmentation from suspected melasma and refer diagnostic uncertainty when necessary.
Rank strength with caveats
B most directly estimates a between-group change for a relevant endpoint, assuming randomisation and measurement are valid. A's photographic contrast and C's open-label satisfaction are weaker causal support. Yet whether six points matter to a particular user depends on baseline, threshold of meaningful change, adverse events and skin tones included.
Create a falsifiable follow-up question
Ask whether the finished formula reduces a defined pigment endpoint relative to a suitable comparator in users resembling the intended audience, with photographs standardised and safety reported. Document sunlight exposure and concurrent products. If pigment appears suddenly or lesions change irregularly, a cosmetic experiment is not a diagnostic substitute.
Melanocytes produce pigment and transfer it to surrounding cells. The diagram explains a mechanism; colour alone does not diagnose a dark spot.
Open full-size image ↗Your lab · decide before revealing answer
A brand combines A's headline '45%' with B's sample size 160 in one advert, implying a 45% pigment reduction proven on 160 people. Identify the scientific error, the best-supported statement and one missing quality check.
Reveal analysis after making your decision
Model reasoning and safety decision
The ad combines incompatible numbers from different studies. B supports only its own measured between-group score change under its study conditions; check practical significance, side effects and generalisability. Neither A nor B proves a 45% pigment benefit in 160 users.
Further research
Related SESH references
Links do not establish treatment of the hypothetical condition.
Cases are fictional training exercises, not clinical diagnoses.
