Measuring Responses for Acceptance and Preference Testing

Effective testing allows sensory researchers to measure consumer responses to products. The acceptability of a product or preference of one product over another is the basic goal of this quantitative testing. Acceptance and preference tests are used for many different scenarios in the product research world, such as:

  • product maintenance
  • product optimization
  • new product development
  • appraisal of market potential
  • advertising claims support
  • managed risk by achieving informed decision making

A key point to remember when doing acceptance and preference testing is to use subjects that are representative of the target population expected to buy the product. Preference and acceptance tests should never use trained panelists.

Preference testing asks questions such as; “Which product do you prefer?” while Acceptance testing asks; “Do you like this product?”, “How much do you like it?”, “What do you like about it?”

Preference testing does not indicate an overall liking or dislike of the products. It simply indicates preference which could mean the “least disliked”.

  • Simple Preference Test: Present two samples and ask “Which do you prefer?” You can either force a decision or allow a “no preference option”. From the statistical analysis point of view, the forced preference method is preferred.
  • Ranking: Ask subjects to put three or more samples in order of preference. Sensory fatigue may occur when too many samples are introduced.

Acceptance tests are aimed at identifying a liking for a product. They can be used for general liking or evaluation of specific attributes. It is possible to infer preference from acceptance scores.

Rating scales provide more detail than a Yes/No response because they give an indication of the degree of liking. It is important that rating scales are balanced to show the number of “like this” is equal to the number of “dislike this”.  A neutral response “neither like nor dislike” should be at the middle of the scale.

  • Category/Intensity Scales: Sample is assigned to one scale using a descriptive term; i.e. Flavor Strength

None     |———————————————-|     Strong

  • Line Scales: Mark a point along a line. The outer limits of the range are marked at each end of the line. Respondent places a mark on a line or gives a number to express the degree of liking.

Not at all Acceptable     |———————————————-|     very acceptable

  • Likeability Scale – 9 Point Hedonic Scale: This scale can be presented in a vertical format with or without numbers corresponding to the degree of liking. Shorter scales can be produced by leaving out the extreme values.

           -Dislike-              -Dislike-              -Dislike-              -Dislike-              -Neither Like-               -Like-               -Like-               -Like-               -Like-
Extremely         Very Much         Moderately            Slightly                Nor Dislike                Slightly          Moderately      Very Much        Extremely

  • “Just About Right” Scales: A five point scale used to determine the appropriateness of the intensity of an attribute.

|——————————-|——————————-|
Much Too Dark        Just about Right           Much too Light

References:
Geoff Walkers Website SST, December 3, 2004.