Lave (1988) argued that our formal educational system is predicated on a mistaken belief in the transfer of abstract knowledge from one situation (the classroom) to another (e.g., the home, the job, the marketplace). Indeed, nearly a century of research in psychology has generated a depressing lack of evidence for the notion of general transfer. Thorndike (1924), the first psychologist to study transfer systematically, showed that training in formal subjects like Latin and geometry had no effect on performance in reasoning tasks relative to training in more mundane subjects like bookkeeping and shopwork. More modem attempts at showing transfer have also been discouraging. For example, there are the classic studies of Hayes and Simon (1977) showing little transfer between isomorphs of the tower of Hanoi puzzle. Continuing in this vein, Jeffries (1978) found little transfer between missionaries and cannibals and waterjug problems, although according to her simulation model, both involved use of a means--ends analysis strategy. Gick and Holyoak (1983) observed little transfer between isomorphs of Duncker's radiation problem. Aside from these laboratory studies ofpuzzle problems, studies of transfer in more realistic school settings have also been largely unsuccessful. For example, Post and Brennan (1976) trained students for several weeks on a general heuristic procedure for solving algebra word problems. Their instructions included such things as "determine what is given" and "check your result." On a problem-solving posttest, the performance of the trained subjects was no better than that of a control group. Other attempts at teaching general problem-solving strategies have been

largely negative (Polson & Jeffries, 1985). Finally, despite early claims that computer programming would emerge as the mental discipline that would revolutionize children's thinking (Papert, 1980), empirical studies have shown little benefit of learning to program on general problem-solving abilities (for a useful review, see Mayer, Dyck, & Vilberg, 1986).