PRODUCT TESTING IN THE SPHERE OF PRODUCT DEVELOPMENT 23 money in solving these problems, our successors at your next symposium may well be able to record some solid achievements. In April 1959 Ovens read a paper on 'The function of consumer testing in product development and marketing' (2). I need not repeat what he said here as it is a matter of record. Suffice it to say that he concentrated on describing techniques for consumer testing new and modified products. I do not dissent from his conclusions: the methods he described for both single and double blind placement tests are in widespread use today and justifiably so, but in the seven and a half years that have elapsed since that paper was read there have been two developments which to my mind must affect current thinking. Firstly, markets for consumer goods have become increasingly competitive (not least those involving the type of products with which you are concerned), and secondly, most if not all existing brands are constantly being improved by their manufacturers. These two pheno- mena create a situation where it is becoming increasingly difficult to produce improved versions of existing products. This in turn has lead to an intensification of the search for 'new' products, whether they be complete innovations (i.e. products not existing in any form hitherto) or radical departures from the normal pattern of products in a particular product field. An example of a completely new product was the first radio examples of the second are more frequently encountered - thixotropic paint and tubeless tyres are but txvo. CHANGES IN EXISTING PRODUCTS Let us now examine in turn each of the aspects of product development I mentioned earlier, dealing in the first place with the improvement or modification of existing products. Here it is important that everyone concerned (the chemist, the tech- nician, and marketing, production and advertising men) should know precisely what objectives the improved or modified product should meet. In parenthesis I should add that I am assuming that changes of the kind I have in mind do not happen by chance, though happily there have been occasions in the past and doubtless there will be more in the future when the scientist lights upon the key to an improvement in an existing product while engaged in work of a quite different nature. In other words, I am postulating the case where there is a conscious effort towards the desired goal of an improved or modified product and that the end product thus sought will meet specific objectives, whether they be improved performance

24 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS or appearance or the substitution of cheaper, or more stable, or more easily obtained materials in the formulation. Mrs. Ludford (1) has already outlined some of the problems involved in product testing, and I have no wish to repeat them. I feel it is important however to stress that any product which reaches the market should have already been subjected to, and emerged successfully from, prior testing by at least two and frequently all three of the following alternatives which I quote from a private document (3): a Expert panels, which can assess the magnitude of the effect of changes in formulation but only rarely their acceptability b postal panels, which can assess the relative preference between two products but only on rare occasions and with special test designs, the motivation behind the preference c consumer tests involving personal interviews, which can assess the relative preference of two products and can often in addition establish the motives leading to the preference and relate it to the market conditions. The standard technique at the consumer stage is the double placement blind test, the modified product being pitted against the existing version. It may well be tested against competition as well if the reformulation was designed to match or gain ascendancy over it. Whilst the technique is reasonably satisfactory if correctly administered by fully trained interviewers who are able to probe respondents' views without biassing them in any way, it is extremely important that the sample of respondents is carefully defined. Clearly whatever sample is chosen it should wherever possible be representative of its universe. The problem lies in defining the universe. For example, in a test involving two hair sprays, one's own brand and the leading competitor, and designed to establish whether an improved product has better holding properties than the competition, should one test among representative samples of a. all adult women, or b. women between 16 and 50, or c. women with modern hairstyles, or d. users of the two brands only, or e. current hair spray users only (and how to define 'current'?), or f. some combination of two or more of these? No universal rule can be laid down the decision must be made ad hoc in the light of knowledge of the market and the specific objectives against which the modified product was formulated. It is perhaps worth stressing