ABSTRACT

INTRODUCTION In this chapter we discuss work on the selection task using thematic or contentful materials. The particular materials used and the difference they make to selection task performance is discussed in detail later. In general, however, the move to thematic materials marks a shift from indicative task rules to “deontic” task rules, i.e. rules that state how the world ought to be, such as, if you are drinking beer, you must be over 18. As Manktelow and Over (1987) pointed out, this marks a profound shift in the nature of the task and perhaps of the underlying cognitive processes involved. We argue in this chapter that while much of the machinery introduced in Chapter 10 is required, this shift in emphasis requires a move to a model where people are regarded as maximising the expected utility of turning a card rather than the amount of information that can be gained about its truth or falsity.