Stochastic Unfolding

Abstract

In survey research we regularly encounter the following type of question: ‘Which of these stimuli do you prefer most?, which of the remaining ones do you now prefer most?’ etcetera. Sometimes a full rank order of preferences is asked in this way, more often only a partial rank order is obtained. Sometimes even only the question is asked: ‘Which k of these n stimuli do you prefer most?’, or, even more generally, ‘Which of these n stimuli do you prefer?’ These questions can be referred to as ‘rank n/n’, ‘rank k/n’, ‘pick k/n’, and ‘pick any/n’ data, respectively. Stimuli may be political parties, candidates, career possibilities or brand names of some consumer good. Rather than asking about ‘preference’ the questions may also be phrased in terms of other evaluative concepts like ‘sympathy’ or ‘importance’. In this chapter I will be concerned with analysing such data of the form ‘pick k/n’ or ‘pick any/n’ data.