Yelena Loginova and her team at Coty set out to “develop a holistic approach to experimental design and testing practices that include consumer perception, expert examination, and image analysis.”
The latter aspect is meant to stand as a controlled, replicable means of explaining product efficacy and understanding cosmetologists’ evaluations as well as consumer experience.
Starting from scratch
“A thorough understanding of the biology, physiology, and growth pattern of the nails is essential for an impactful nail product development,” the researchers explain in the preprint abstract published by the SCC. That understanding, which includes biological and environmental factors of nail growth and health, helps guide researchers’ selection of test participants so as to yield legible results. With this in mind, Loginova’s team established some basic testing parameters.
Participants’ nails should be neither too long nor too short; product should be tested on the thumb and middle finger of each hand, since nail growth varies by finger and hand; those fingernails should each have distinct lunula, as this is (when notched with a cosmetologist’s diamond scribe) a consistent baseline for growth measurement.
Perception, evaluation, analysis
Overall, “the beauty of the nail depends on their shape, dimension, shine consistency, etc.,” as the team explains in the published abstract.
So features including nail ridges, peeling, growth rate, length, and strength take on relevance, whether or not a product can influence them. “The growth of nails and their appearance indicate their general health,” confirm the researchers in the published abstract.
Conventionally, consumer perception and evaluation by professional cosmetologists (using tools like the Cuticle Dryness Grading Scale, the Nail Moisture Scale, and the Nail Peeling Scale) have been the basis of nail care product development testing.
The Coty team looked at other influential factors and sought a more fact-based evaluation method.
Product delivery
The packaging and texture of nail care products influence consumer perception of quality and, apparently, efficacy.
The Coty team worked with two distinctly textured products to put together its testing recommendations: one, a gel in a narrow-tipped tube, and the other, a liquid in a polish-style bottle with the brush-in-cap feature. When consumers’ impression of product efficacy was based on the container and texture, their perception didn’t always directly correlate to quantitative findings.
And Loginova pointed out that beyond product delivery and benefits, a given consumer’s personal preferences factor into how they self-evaluate nail growth.
Microscopic imaging
The multidimensional nail care product efficacy testing method Loginova and her team settled on incorporates microscopic benchmarks of appearance.
Adding the evaluation of nail images, taken with an Olympus Research Stereo Microscope equipped with a camera, to the conventional consumer perception and cosmetologist evaluations, the team established testing that better supports both claims and takes subjectivity into account.