Creating Algorithms as an Aid to Judgment

Abstract : The strategy for aiding judgment presented in this report is algorithmic decomposition. To use this approach, a complicated or unknown quantity is decomposed into a number of subproblems that are more manageable or can be estimated more readily. Answers to the component parts of the problem are then combined according to a set of rules (an algorithm) to yield an answer to the original problem. In this experiment we gave subjects questions concerning facts they would be unlikely to know but could estimate and provided subjects with a wrong answer. The subjects' task was to decide whether the given wrong answer was too high or too low. After completing four such items, subjects were given tutorials on how to create algorithms, based on facts they knew or could estimate, to help them in their task. The they completed four more items under instructions to write an algorithm for each one. These efforts to teach subjects to create their own algorithms were successful in the sense that most subjects were able to write algorithms for the questions we gave them. However, the increase in accuracy of their decisions as a result of creating and using algorithms, from 65% to 69%, was only marginally significant and unimpressive in size. (Author) (kr)