The present study was concerned with the effects of education level and area of expertise on performance on the standard abstract selection task. Subjects had received bachelor's or doctoral degrees. Contrary to some recent results reported by Hoch and Tschirgi (1985), no effect of education level was found. However , there was a significant effect for area of expertise. Subjects trained in mathematics performed better than subjects from computer science, electrical engineering, and the social sciences. An explanation in terms of the mathematics subjects' greater likelihood of using a disconfirmation strategy and greater familiarity with the relevant propositional logic is offered .Since Wason's first report on the selection task in 1966, researchers have attempted to explain why performance is so poor on this particular deductive reasoning problem. Typically less than 10% of the subjects make the correct selection. Most research has focused on the effects of problem content and other task variables, with varying results (see Evans, 1982, andGriggs, 1983, for reviews of the selection task literature) . Recently, however, some attention has focused on subject variables . Hoch and Tschirgi (1985) reported data that suggests an education effect; that is, subjects with more education perform better on the task. The present study examined this factor , along with another subject variable, area of training or expertise. Because the standard abstract form of the task was used, we will describe it before we further detail the Hoch and Tschirgi research and the present study.The selection task is based on the logic of a material conditional rule. In its standard form, the problem involves a rule of the form, "If P, then Q," and an array of four cards representing P, NOT P, Q, and NOT Q, where P and Q are usually letters and numbers. For example, the subject may be presented with four cards that display C, E, 5, and 8 and the rule, "If there is a C on one side of a card, then there is a 5 on the other side. " The subject is told that each card has a letter on one side and a number on the other side and is asked to select only the card or cards that need to be turned over in order to determine whether the rule is true or false with respect to these cards .The correct answer according to standard logic is P and NOT Q (C and 8 in the example) since these are the only cards that can possibly falsify the rule . A number other than 5 may be on the other side of the C card , and a C may be on the other side of the 8 card. The most common errors made are choosing only the P card (C in the This article is based on a master's thesis completed by the first author under the second author's supervision. Requests for reprints should be sent to Richard A. Griggs, Department of Psychology , University of Florida, Gainesville, FL 3261 I. example) or choosing the P and Q cards (C and 5 in the example).In stark contrast to the typically observed poor performance on the standard abstract form of the task, Hoch and Tschirgi (1985) found a...