Biomedical subjects

Steven A Hecht

Publications and source records attributed to Steven A Hecht.

4 recordsLinked to original sources

PubMed2006

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-so-good retrievers retrieved correct answers less often than the other participants in both the choice-allowed 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.

Adolescent↗

PubMed2003

Sources of individual differences in fraction skills.

The purpose of this investigation was to evaluate a conceptual model of relations between two kinds of mathematical knowledge (simple arithmetic and conceptual knowledge), two kinds of child characteristics (working memory and on-task related classroom behavior), and individual differences in three kinds of fraction outcomes (fraction computation, estimation, and word problems) in 105 fifth grade students. Structural equation modeling provided consistent evidence that conceptual knowledge independently contributes to individual differences in the three fraction outcomes. Simple arithmetic knowledge was uniquely related only to variability in fraction computation skills. Mathematical knowledge was found to mediate some of the contributions of both working memory and classroom behavior on variability in fraction outcomes. These supported mediating processes extend the current literature by explication of the pathways via which characteristics of children may affect individual differences in fraction outcomes.

Child↗

PubMed2002

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.

Analysis of Variance↗

PubMed2002

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.

Humans↗