Conditioning Agents for Hair and Skin

Evaluating Effects of Conditioning Formuiations on Hair 327
to give a grade number that can be used to compre various products. Since
other scales can also be employed, including individual scales for each participating
panelist, any scale can be calibrated by calculating the percentage rating
based on the "top rating" characteristic for each test participant. Thus, the
calibration facilitates the comparison of the ratings from panelists employing
different rating systems (62). Further discussion of various advantages or disadvantages
of rating systems, including the use of a bipolar scale for liking/disliking
as well as ratio scaling and magnitude estimation, is given in Ref. 62.
2. Salon Testing
The next step following the analysis of hair tresses is prototype screening on a
small scale by an internal expert panel in R&D or by salon testing (63). Salon
testing is usually conducted by product formulators together with salon stylists.
Before the test is carried out, a salon operator has to make appointments with
panelists possessing a hair type appropriate for a tested product (thin hair,
damaged hair, etc). During the actual test, the most widely used procedure
involves the half-head application of a prototype product with the second halfhead
left untreated or treated with a control formulation. A variety of hair
properties can be evaluated on both the prototype- and control-treated side
of a head. For conditioners, the key parameters are (1) ease of combing, (2)
feel, (3) body, (4) static charge, (5) residue on hair, (6) extent of hair moisturization,
(7) buildup upon multiple product application, and (8) removability by
shampooing. The test participants also assess the ease of product application,
consistency, and color. A detailed questionnaire may be developed including
a rating system and questions similar to those presented in Tables 2 and 3. The
formulator and the stylist participate in product application, and their inputs,
in addition to the opinion of a panelist, are included in the test protocol. Several
panelists are usually treated with the same product in order to gather more
representative information about the product tested.
3. Consumer Testing
Apart from expert panels, guidance for product development and the evaluation
of the final product acceptance can be provided by a consumer panel
which comprises the final users of the product. Consumer panels can be organized
for the analysis of various problems related to the development of a
product, including a descriptive analysis panel, a screening panel, or a quality
control panel. In addition to this, a home-use consumer test serves as a critical
step in the development of a new conditioner. This type of test may include
the analysis of a single product or a paired comparison of two different products.
An example of the testing protocol as well as the hypothetical test results
for a conditioner designed for chemically processed (damaged) hair is given
in Table 2. The results demonstrate a very favorble consumer reaction to the