PRODUCT TESTING IN THE SPHERE OF PRODUCT DEVELOPMENT 25 that the test results should be interpreted with the sample employed very much in mind if misleading conclusions are to be avoided. It often happens in double placement blind product testing that the test product is not preferred either overall or in any of the sub-samples whether these be of respondents in particular demographic categories or users of particular types or brands of the product in question. Should the test product be rejected, or reformulated and re-tested, in such circum- stances? There can be no all--embracing answer to this question either. Action should be related to the objectives of the product test, but it may be worth considering the possibility of a. repeating the test with the same sample of respondents to ascertain the stability of their preferences, to isolate the discriminators among them and to measure intensity of preference in an attempt to throw further light on the meaning of the test results b. re-interviewing the minority who preferred the test product to probe more deeply the reasons for their choice and the strength of their opinions about it c. carrying out an extended usage test to ascertain whether the test product gains in popularity with greater familiarity. Whether or not any of these additional steps are taken must be decided in the light of the original objectives. Further action will only be taken generally speaking when it is thought that the test product might have a minority appeal which could prove profitable. One of the aims of this second stage research would then be to delineate this minority in meaningful terms, whether they be the more usual demographic or usership categories or psychological or behavioural traits. It follows that such action would not normally be taken if the test product were designed to compete in the same market as the brand leader against which it was tested, or if the double placement test results indicated a product deficiency on any essential characteristic. I should add here that in the present state of development of consumer research techniques no valid yet practical and simple means of assigning people to useful psychological categories, e.g. extroverts and introverts, has yet been found. Such methods as exist tend to be far too cumbrous for general use. What is needed is a means of achieving the desired ends merely by asking three or four questions. A great deal of work has already been done in this area and there are distinct possibilities of success.

26 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Other forms of comparative testing such as taste tests, and sniff tests for perfumes, are permissible where only one variable is involved and may well prove useful in sorting out products for further consumer testing from a range of possibilities. Tests of this type are often cheap and simple to administer, but as in all consumer testing, the objectives must be clear, the sample adequately defined and the results carefully interpreted. Such tests, however, fail to satisfy one of the most important criteria for product testing - that the products under test should be used in as normal a situ- ation as possible, and the findings should therefore be interpreted with the particular test situation in mind. The whole area of product testing in which sensory perception is involved is one in which a great deal still needs to be done to improve existing techniques. The weaknesses in present methods stem mainly from the inability of many people to communicate their impressions to the inter- viewers. This inability is not helped by our inadequate vocabulary. Even experts would find it very difficult if not impossible to describe a perfume in such a way as to conjure it up in another expert's mind with any degree of precision. Commonly, whatever the difference between two test tooth- pastes for example, most reasons for preferring one or the other are con- cerned with taste similarly in the case of soft drinks most comments concern flavour or sweetness, even if the difference is one of carbonation. Perhaps the solution to this problem lies in the area of non-verbal responses. Much experimental work has already been done using psycho- galvanometers to measure the degree of perspiration on the skin which, it is said, varies involuntarily depending on outside stimuli. Measurement of pupil dilation is another technique currently being advocated. At the present time the latter appears to be better able to measure reactions to visual and aural stimuli, but work on reactions to touch and smell is in hand. Both these techniques must be regarded as experimental but usable measures may well be developed from them in the reasonably near future. I have referred earlier to postal tests. In my experience, covering some dozens of tests involving a wide variety of toiletry products and where the test was later repeated using personal interviewers, in only one case has the preference differed for the two techniques. As an interesting aside perhaps I ought also to state that in a large number of personal interview double placement blind tests, on only very rare instances has the preference established in the first fifty completed interviews differed in direction from the final result, despite the often seriously unrepresentative nature of the first fifty interviews in terms of sex, age, product usage etc.