J. Sec. Cosmetic Chemists 19 37-52 (1968) (•) 1968 Society of Cosmetic Chemists of Great Britain The role research of consumer studies in MRS. S. M. LUDFORD* Presented at the Symposium on "Product Testing", organised by the Society of Cosmetic Chemists of Great Britain in Eastbourne, Sussex, on 14th November 1966. Sltnopsis--The use of consumer studies to help guide the research chemist, developing new or improved consumer products, is briefly discussed. Once clear objectives oeor such tests have been defined, keeping in mind the limitations of such tests, a panel of consumers of suitable size and characteristics can be specified. The design of the test, questionnaire, and analysis oi results also depend on the objectives and these considerations are discussed, along with the importance of the visual presentation of the test products. Although much remains to be done in developing reliable test methods, consumer studies can be very valuable tools in guiding research. INTRODUCTION Whenever a test of any sort is planned, it is extremely important that the objects of the test should be clear. Often, a research worker has an idea or theory and wishes to know whether or not it is plausible. A test or tests are planned which are designed to examine the theory and confirm or reject it. Research into products for sale to consumers involves theories about the interaction of products and consumers and, providing that these theories can be clearly stated, it is possible to design a test or tests, in- volving consumers to examine the theories. In fact, in the toiletries and cosmetics fields, where interest centres on skin, hair and teeth, satisfactory in vitro testing is difficult to achieve and tests involving human subjects are often necessary at an early stage. *Unilever Research Laboratory, Isleworth, Middlesex. 37

38 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Having conceived an idea for a new or improved consumer benefit, the product development chemist is concerned to formulate it into an optimum product which can be passed to the marketing department. The object of this paper is to indicate the part that consumer studies can play in helping the product development chemist in research. TESTING INGREDIENTS Usually there are several possible compounds available which might be suitable for imparting the proposed consumer benefit. Some form of testing is required to screen out the most suitable ones. Although, if availa!,le, laboratory in vitro tests can help, often a check on live subjects is the most satisfactory test. Providing that there is sufficient information on the safety aspects, human subjects may be used to provide the substrate for application of the ingredient. The effects can be measured instrumentally or, in the absence of instruments, an expert judge or panel of expert judges may be used. Subjective opinions are not usually very valuable at this stage. Sometimes new compounds become available and it is necessary to find out what consumer benefits, if any, they offer. Again, if sufficient safety information is available they may be tested on human subjects as above. In order to keep the test as objective as possible when judges are used, it may be advisable to have only one aspect judged at a time. For example, if a new compound is applied to one half of a head of hair and the other half is left untreated as a control, one judge could be asked to assess the shine on the two halves. The judge should not know which is the treated side and which the untreated and this visual judgement should be made under standard lighting conditions. When a judgement of the feel of the hair is required, it may be better to ask another judge to assess this, under con- ditions where visual differences cannot be assessed. This would avoid any halo effect of a good gloss on one side causing judges to expect a difference in feel between the two sides. When only one judge assesses all aspects, analysis can show if one aspect is highly correlated with another but the correlation may either be a real one, i.e. the product could actually improve both gloss and feel of the hair, or it could be due to the judge associating the two aspects subconsciously. If several judges are used, unless the same aspects were subconsciously associated by all judges, this individual effect should be shown up. If only one judge is available, perhaps different heads should be used for judging each aspect. There will be head to head variation