MEASURING INDIVIDUAL-DIFFERENCES IN CHILDRENS ADDITION STRATEGY CHOICES

A test of individual differences in addition strategy choices was devi sed and its psychometric properties were analyzed. The test was used t o examine how individuals' accuracy of retrieval was related to their use of backup strategies (e.g., counting on fingers) and the accuracy of their backup strategies. Strategy use and errors of 105 6-year-olds was recorded on all 100 single-digit addition problems. Children were randomly assigned to the ''exploratory'' or the ''validation'' subsam ple. In the exploratory subsample, discriminant analyses reduced the 1 00 items to 2 sets of 20 items: each test discriminated good students, not-so-good students, and perfectionists. In the validation subsample , the 2 forms' reliabilities exceeded .90 on all variables, classified 74% of the children similarly, and showed similar relations to other variables. Not-so-good students had lower achievement scores than good students or perfectionists in math computations but not math applicat ions. Children's frequency and accuracy of backup strategy use and bac kup strategy accuracy functioned independently to reduce their retriev al errors.