ABSTRACT
One of the most fascinating aspects of our cognitive system is its adaptivity. In a wide variety of domains, such as mathematics, memory, spelling, decision making and question answering, it has been shown that people select their strategies in response to task instructions (e.g., Gardner & Rogoff, 1990; Reder, 1987), problem features (e.g., Lemaire & Siegler, 1995; McDougall & Velmans, 1993; Rittle-Johnson & Siegler, 1999), and the success rate of the strategies in the past (e.g., Lemaire & Reder, 1999; Reder, 1987). In doing so, people tend to solve problems by using the most efficient strategies available. To explain why people's strategy choices are adaptive, it is often suggested that all relevant features of the problem situation are taken into account. Recent strategy selection models, such as ASCM (Siegler & Lemaire, 1997; Siegler & Shipley, 1995), SCADS (Shrager & Siegler, 1998) and ACT-R (Lovett & Anderson, 1996), assume that this process consists of a weighting of the benefits (accuracy, speed) and the costs (processing resources) of the strategies, as experienced through their previous application. Depending on the instructions, either stressing accuracy and/or speed, or on the features of the problems, different strategies may be the most beneficial and/or the least costly, and thus the most adapted to a situation.
