Effectiveness of positive hypothesis testing in inductive and deductive rule learning

In a positive hypothesis test a person generates or examines evidence that is expected to have the property of interest if the hypothesis is correct, whereas in a negative hypothesis test a person generates or examines eviden ce that is not expected to have the property of interest if the hypothesis is correct. Two experiments assessed the effectiveness of positive versus n egative hypothesis tests on inductive and deductive rule learning problems. In Experiment 1 problem solvers induced a rule by proposing hypotheses and selecting evidence in the eight conditions of a factorial design defined b y instructions to use a positive or negative hypothesis test on each of tri als 1-5, 6-10, and 11-15, Instructions to use positive tests resulted in mo re examples, fewer strategic hypotheses, and a higher weighted score for fi ve types of hypotheses than instructions to use negative tests. In Experime nt 2 problem solvers identified 1 of a possible 1296 correct rules in the d eductive rule learning game Mastermind. When problems were classified in th e 16 possible combinations of positive or negative hypothesis tests on tria ls 2, 3, 4, and 5 there were fewer trials to solution for positive tests on each of the four trials and fewer trials to solution with increasing posit ive tests. We conclude that positive hypothesis tests are generally more ef fective than negative hypothesis tests in both inductive and deductive rule learning. (C) 1999 Academic Press.