ABSTRACT
O ur chapter focuses on a research question that is relevant in differentareas of psychology: Which information is an individual genuinely inter-ested in when performing a certain task? This question is important because active interest in a specific item of information is an indicator (albeit not a perfect one) that this information is utilized when the person works on the task. Tasks with information search may consist of solving a problem, constructing a mental model of a scenario, or coming to a decision. Data about the information used – or not used – in cognitive processes are central to theory development as many theories explicitly predict the use of specific types of information used, or specific patterns of information acquired (for decision making, see: Beach, 1990; Huber, Huber, & Bär, 2010; Montgomery & Willén, 1999; Johnson, SchulteMecklenbeck, & Willemsen, 2008; Tversky, 1972). It should be noted that people may utilize types of information that are not envisaged by a theory. Examples are risk-defusing actions in traditional theories of risky decision making. Thus, the measurement of information needs and information acquisition patterns are indispensable prerequisites for a test of models. If an experimenter wants to investigate the role of probabilities in a risky choice task there are two traditional groups of methods available:
1. The experimenter directly presents probabilities varied between conditions together with other information to the decision maker and afterwards analyzes the decisions in order to determine which effect probability had on choices (input-output or paramorphic approach). This approach can
investigate the role of a specific type of information (e.g., probability) when it is presented to the decision maker at the beginning. However, it may force the probability information on the decision maker, and it cannot be ruled out that – without presentation by the experimenter – a person would not be interested in probability at all. Furthermore, this method does not provide information about information acquisition patterns.
