5.1 Acceptance and preference are the key measurements taken in consumer product testing as either a new product idea is developed into testable prototypes or existing products are evaluated for potential improvements, cost reductions, or other business reasons. Developing products that are preferred overall, or liked as well as, or better, on average, compared to a standard or a competitor, among a defined target consumer group, is usually the main goal of the product development process. Thus, it is necessary to test the consumer acceptability or the preference of a product or prototype compared to other prototypes or potential products, a standard product, or other products in the market. The researcher, with input from her/his stakeholders, has the responsibility to choose appropriate comparison products and scaling or test methods to evaluate them. In the case of a new-to-the-world product, there may or may not be a relevant product for comparison. In this case, a benchmark score or rating may be used to determine acceptability. A product or prototype that is acceptable to the target consumer is one that meets a minimum criterion for liking, and a product that is preferred over an existing product has the potential to be chosen more often than the less-preferred product by the consumer in the marketplace, when all other factors are equal.
5.2 The external validity (the extent to which the results of a study can be generalized) of both acceptance and preference measures to manage decision risk at all stages of the development cycle is dependent on the ability of the researcher to generalize the results from the respondent sample to the target population at large. This depends both upon the sample of respondents and the way the test is constructed. Within the context of a single test, acceptance measures tell the relative hedonic status of the two samples, quantitatively, as well as where on the hedonic continuum each of the samples falls, that is, “disliked,” “neutral,” or “liked.” In contrast, preference measures tell the relative choice status of two samples within a specific respondent group. Results from these measures can and will vary from test to test depending on the number and type of respondents serving in each test, the size and nature of the sensory differences between the two samples, the method of executing the test, and any error present in the test. The identification, control, measurement, and tracking of variables that may influence results across tests (for example, production location, sample age, and storage conditions) are the responsibility of the researcher.
5.3 While measures of acceptance and preference are both subjective responses to products, and can be somewhat related, they provide different information. A product may be “acceptable” but still not be preferred by the consumer over other alternatives, and conversely, a product may be preferred over another but still not be acceptable to the consumer. These two terms, therefore, should not be used interchangeably. When a bipolar hedonic scale with multipoint options is used, the researcher should specifically refer to “liking,” “acceptance,” or “hedonic ratings.” When preference measures are used, the researcher should refer to, “preference,” “product selection,” or “choice.” Research professionals themselves should be precise in their usage of the terms “acceptance” and “liking,” to refer only to scaling of liking. These researchers should use the terms “preference&......