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The Ingredients of Skin Care Research
By Kimberly J. Heathman
Posted: April 28, 2008, from the August 2007 issue of Skin Inc. magazine.
page 2 of 3
Independent research. Independent research, sometimes called third party research, is conducted by experts who have nothing to gain or lose from the results of the study. This research is intended to provide strict objectivity.
In the case of ingredient testing, for example, any research conducted by the manufacturers of ingredient XYZ—who have invested time, money and advertising dollars in the product—couldn’t be objective. An independent group, such as the Cosmetic Ingredient Review (CIR), is by definition one whose primary concern is to assess the safety of ingredients used in cosmetics in an open, unbiased, expert manner, and to publish the results in open, peer-reviewed scientific literature.
Quantitative research. Quantitative research addresses qualities that can be measured or quantified. These measures represent facts, not opinion. If the CIR were to test ingredient XYZ on a quantitative scale, its concerns might include if the ingredient meets or exceeds the national standards established for cosmetic safety, or if ingredient XYZ contains substances in amounts higher than what is considered safe for consumers.
Qualitative research. Qualitative research is concerned with more subjective aspects, such as the quality of a product or ingredient, and collects opinions and descriptions from subjects exposed to a particular ingredient, product or treatment. Results may be reported as testimonials. For example, “Ingredient XYZ made my skin softer,” or “Ingredient XYZ caused redness and a rash on my skin.”
Sample size. Sample size refers to the number of people or items involved in doing research in a particular trial.
In quantitative research, multiple samples of ingredient XYZ should be tested. Ideally, random sampling would be used. This means samples are tested at random on many different subjects.
In qualitative testing, a large number of subjects should be exposed to the ingredient, product or treatment. For example, ingredient XYZ should be tested on different skin types and ages—not just a few people displaying a specific skin type, condition or non-condition.
Variables. In testing, certain variables or factors must stay the same for results to be valid. For example, when comparing two samples of skin care product ABC, containing ingredient XYZ, you would test the same percentage of ingredient concentration per subject. In addition, if you compared, for example, the results on an animal subject versus human subject, the test results wouldn’t be meaningful.
The validity of initial research studies
Making sure research is accurate and valid requires more than one spin around the lab. The following are important factors in ensuring acceptable research results.