THE ROLE OF CONSUMER STUDIES IN RESEARCH 39 but this occurs anyway and judgement on several heads would have to be made. It is best if the compound can be applied under strictly controlled conditions by a third party. Since judges must not know which side is which, they cannot apply the compound, unless two compounds which are both applied in the same way and look and behave similarly from the point of view of application are being compared on one head. Self application of materials not incorporated into a prototype product is best avoided. TESTING PROTOTYPE PRODUCTS Having found suitable ingredients, it is necessary to formulate them into satisfactory products, that is, products which allow the ingredient to have its effect and which are also acceptable in themselves. A shampoo, say, containing miracle ingredient X, must be an acceptable shampoo as well as giving X the opportunity to work its miracles. If it were possible to add the ingredient to a good, established product and be sure that the ingredient still exerted its effects without disrupting the properties of the product, it would only be necessary to find out whether consumers could detect the effects of the added ingredient and whether or not they liked it. Unfortunately some interaction usually occurs and a compromise is necessary to find the formulation showing the greatest effect of the ingredient combined with the least disturbance of the general product characteristics. Objective tests on human subjects are again useful in assessing possible products although, where subjects apply the product themselves, their subjective opinions on the method and ease of use may also be useful. Further information about the method and ease of use may be obtained by giving some panelists the product with any essential instructions for use and leaving them to use it instead of rigidly controlling the conditions. Discreet observation can indicate where improvements could usefully be made. Once the number of possible products has been narrowed down to a small number, say three or four, these products can be given to a suitable panel of consumers for their assessment. Great care is necessary with words when consumers' assessment is used. An ingredient or a product may be shown, in the laboratory, to have certain properties during use by a consumer it may be considered to have certain attributes and the two are not necessarily the same thing. For example, a

40 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS new toilet soap may be shown to be much milder to the skin than a control soap in objective, laboratory tests. This does not mean that a consumer will consider it milder when she compares these two soaps in use, since mildness to the consumer is not the same thing as mildness in laboratory test terms. Therefore, it is necessary to be extremely careful to bear this in mind when using consumers' assessments. TESTING "FINAL" PRODUCTS All the above testing has been "introvertive". Once an optimum product has been selected an "extrovertive" test is necessary, to see whether the product is satisfactory by comparison with other things which are available to achieve the same consumer benefit. If the product is entirely revolutionary and there is nothing with which to compare it, further testing can be carried out to see what its main advantages and disadvantages are from the consumer's view point. Beyond that, for attitude surveys, concept testing, etc., market research testing is necessary and that is outside the scope of this paper. PANEL SELECTION Once the objectives of the test have been clearly defined, it is possible to consider what kind of people should be included in consumer tests and how they can best be used. For consumer studies designed to guide research it is not necessary to have a panel which is representative of the population in social status it is much more useful to have an intelligent, literate and articulate panel. Selection of panelists for a particular test should be based on character- istics relevant to that test. These might include age group, hair type, "usual" products used on the hair, etc., for a hair product test no dentures, usual toothpaste, frequency of tooth cleaning, etc., for a dental product test and so on. It is useful to have a large panel available, from which smaller panels can be drawn for particular tests. From background data for the total panel, of personal characteristics, product usage, etc., a suitable panel for any one test can be selected, providing the original panel is large enough. This has the advantage of saving the time and money necessary to recruit a fresh panel for every test. It does mean that panelists become used to taking part in tests and are no longer typical consumers. However, even a