Comparing touch senses of naïve and expert panels through treated hair swatches: which associated wordings correlate with hair physical properties?

OBJECTIVES: This study (i) compared the sense of touch between a naïve and expert panels, under visual or blind conditions, using differently treated hair swatches and (ii) explored possible common wordings used by both panels and their possible links with some physical properties of hairs.

METHODS: Two sets of 15 hair swatches of Caucasian and Chinese origins were differently treated (bleached, permed, brushed, etc.) or organized (root-tip vs. tip-root). These were evaluated by tactile assessments by two panels (105 naïve consumers and 10 hair experts) under visual or blind conditions, in two geographical locations. A series of 17 defined antonym adjectives, as descriptors, allowed responses of each panel to being scored and their preference mappings to being defined on a like-dislike scale. Hair swatches were measured and assessed by various instrumental techniques (bending, diameter, cuticle cohesion, alignments of hair).

RESULTS: Apart from a few overlaps, all 15 hair swatches were well differentiated by both panels which showed a global agreement, making experts reliable assessors. Only three descriptors among 17 correlated with some objective measurements. Tactile-visual assessments differ from those performed tactile blind in both panels. Agreements between both panels appear, however, closer under tactile-blind conditions.

CONCLUSION: Trained hair experts were confirmed as reliable representatives of a larger and naïve cohort, viewed as consumers. Hair swatches were well differentiated by both panels, with comparable descriptor rankings.