Steven A. Hecht

Counting on working memory in simple arithmetic when counting is used for problem solving

A concurrent-task methodology was used to investigate relations between the availability of aspects of working memory resources and both strategy selection and execution while simple addition equations (e.g., 4 + 3 = 8) were being verified. Consistent with prior research in which production trials have been used, undergraduates selected a variety of procedures other than retrieval. Availability of working memory resources did not generally affect strategy selection. Disrupting central executive and phonological aspects of memory affected strategy execution, but only when min counting was used to solve the problems. These and other features of the results suggest that availability of working memory resources does not contribute to individual differences in strategy selection and time to execute retrieval processes.

Emergent Literacy Skills and Training Time Uniquely Predict Variability in Responses to Phonemic Awareness Training in Disadvantaged Kindergartners.

The factors that predicted variability in responses to phonemic awareness training were investigated in kindergartners who live in poverty. Treatment children (n=42) received both analytic and synthetic phonemic awareness computer-assisted instruction, while controls (n=34) received no special training. Mean age of participants was approximately 5 years 7 months. Pretests included initial phonemic awareness, letter knowledge, word-level reading, invented spelling, vocabulary knowledge, and print concepts. Spelling skills emerged as the best consistent predictor of variability in phonemic awareness in response to instruction. We propose that relations between phonemic awareness and spelling skills are bidirectional: Spelling influenced growth in phonemic awareness and phonemic awareness contributed to growth in spelling skills. The amount of exposure that children had to the treatment intervention contributed uniquely to individual differences in posttest levels of phonemic awareness and spelling.

Individual solution processes while solving addition and multiplication math facts in adults

Contrary to predictions of current solution process models, adults used a variety of procedures other than retrieval to solve addition and multiplication math facts. Predictors assumed to capture retrieval processes posited by such models did account for a substantial proportion of variance in averaged retrieval solution times. But most of the variance in individual participants’ retrieval times remained unaccounted for. Cross-operation associations in patterns of strategy use and retrieval latencies were obtained. Adults with stronger higher level math achievement were more likely to use retrieval, solved math facts faster and less variably, and executed retrieval processes posited by current solution process models faster than participants with less math attainment. The results are explained within the context of the adaptive strategy choice model.

Group differences in adult simple arithmetic: good retrievers, not-so-good retrievers, and perfectionists.

We used the choice/no-choice methodology in two experiments to examine patterns of strategy selection and execution in groups of undergraduates. Comparisons between choice and no-choice trials revealed three groups. Some participants (good retrievers) were consistently able to use retrieval to solve almost all arithmetic problems. Other participants (perfectionists) successfully used retrieval substantially less often in choice-allowed trials than when strategy choices were prohibited. Not-sogood retrievers retrieved correct answers less often than the other participants in both the choiceallowed and no-choice conditions. No group differences emerged with respect to time needed to search and access answers from long-term memory; however, not-so-good retrievers were consistently slower than the other subgroups at executing fact-retrieval processes that are peripheral to memory search and access. Theoretical models of simple arithmetic, such as the Strategy Choice and Discovery Simulation (Shrager & Siegler, 1998), should be updated to include the existence of both perfectionist and not-so-good retriever adults.

Latent variable modeling and cross-national differences in college-level academic performance

Abstract This chapter offers a critique of the latent variable modeling approach taken by Ransdell et al. Suggestions for improving the analytical strategy are described, including the use of confirmatory factor analysis in conjunction with structural equation modeling. The chapter concludes with some examples of confirmatory factor analysis and structural equation modeling from other data sets in order to demonstrate each techniques advantages and disadvantages. Finally, several directions for future research, including the use of longitudinal methods, are suggested in order to help constrain the direction of causative links between academic performance and its predictors.