Consumers Report Preferences When They Should Not: A Cross‐cultural Study

Abstract

If a chi‐squared analysis were to be performed to determine whether preferences were significant in a paired preference test, the appropriate expected frequencies in the analysis would represent those that would occur should the consumers have no preference. One way of determining these ‘no preference’frequencies, for a particular test situation, would be to note the preference responses obtained when the stimuli were putatively identical. Over 2000 consumers were given paired preference tests in which the stimuli were putatively identical. Response conditions and consumer groups were varied and the proportions of preference and no preference responses were noted. In a preliminary experiment, further research was seen to be justified when for putatively identical stimuli, judges did not exclusively express lack of preference; many expressed a preference for one or other of the stimuli. Further experiments were conducted using a written response condition and putatively identical potato chips (potato crisps) as stimuli. Using a single ‘no preference’option, variation in the placement of this option at either first, second or third place on the response sheet had no significant effect on the response frequencies. The proportion of ‘no preference’responses was approximately 30% in all cases. A previously reported 40‐20‐40 distribution was not always confirmed. The experiment was repeated with Korean consumers; these had fewer ‘no preference’responses. Deriving preferences from hedonic scales, rather than having judges respond to preference options, increased the proportion of ‘no preference’responses, with American judges still having more than Korean judges. Yet there are logical objections to extracting preference data from hedonic scales. Increasing the number of ‘no preference’options to two or three, had the effect of increasing the number of ‘no preference’responses up to as much as approximately 60%. Extending the results to Koreans, using two ‘no preference’options, it was seen that only the judges in an anonymous response condition had significantly fewer ‘no preference’responses than Americans. The use of these response frequencies as expected frequencies in chi squared analyses was illustrated, after adjustments for counterbalancing.

Relating consumer and trained panels’ discriminative sensitivities using vanilla flavored ice cream as a medium

“…It is worth noticing that it appears that for a d 0 of 0 (no sensory difference), one would probably not observe 0% of expressed preference. This confirms other research that showed that the proportion of Ôno preferenceÕ answers when presenting identical products will range from 8% to 30% (Ennis, 2001;Marchisano et al, 2003).…”

The paired preference test and the ‘No Preference’ option: was Odesky correct?

“…Yet, the authors are aware that quite often preference tests are conducted on products that are still arguably confusable. If the products were confusable, the data generated by consumers who could not discriminate would have the potential to bias the results (Marchisano et al, 2003). Because consumer preference testing is expensive, this would be a waste of money, especially because it is simple to make an informal check that the stimuli are not confusable.…”

“…Several authors (Lawless & Heymann, 1998;Marchisano et al, 2003;Odesky, 1967;Resurreccion, 1998) have reviewed the various options that have been used to enable data analysis in terms of binomial statistics. These range from ignoring the ÕNo PreferenceÕ responses, splitting them equally between the two preference options or splitting them proportionately between the preference options according to their respective frequencies.…”

Be your own placebo: A double paired preference test approach for establishing expected frequencies

“…With the 'No Preference' option omitted, the analysis becomes a matter of simple binomial statistics. If a 'No Preference' option is included, analysis of the resulting trinomial data is more complex (Marchisano et al, 2003). Therefore, some authors have argued for the omission of the 'No Preference' option.…”

“…Various ways that data obtained with the 'No Preference' option can be analyzed by binomial statistics have been reviewed yet not necessarily recommended (AlfaroRodriguez et al, 2005;Lawless & Heymann, 1998;Marchisano et al, 2003;Odesky, 1967;Resurreccion, 1998). These range from ignoring the 'No Preference' responses, splitting them equally between the two preference options or splitting them proportionately between the preference options according to the respective preference frequencies.…”