Estimation strategies of four groups

Selected groups of 44 academic “pure” mathematicians, 44 accountants, 44 psychology students, and 44 English students were given Levine's (1982) computational estimation task, which involved mentally estimating the products and quotients of 20 multiplication and division problems and describing their strategies. The mathematicians were the most accurate estimators, and the English students the least accurate, with psychology students and accountants obtaining similar scores intermediate between the other groups. All groups demonstrated an impressively versatile use of appropriate strategies. The mathematicians and accountants used significantly larger numbers of appropriate strategies than the other groups and strongly resembled one another in this respect, despite the significantly greater accuracy of the mathematicians. All the non-mathematician groups used significantly larger numbers of inappropriate strategies than did the mathematicians. We discuss (1) the implications for cognitive psychology of the great variability of strategy use in an apparently simple task; and (2) the relationship between people's mathematical knowledge and experience and their estimation accuracy and strategy variabilit