Biology Undergraduates' Misconceptions about Genetic Drift

This study explores biology undergraduates' misconceptions about genetic drift. We use qualitative and quantitative methods to describe students' definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct misconceptions about genetic drift. The accuracy of students' conceptions ranges considerably, from responses indicating only superficial, if any, knowledge of any aspect of evolution to responses indicating knowledge of genetic drift but confusion about the nuances of genetic drift. After instruction, a significantly greater number of responses indicate some knowledge of genetic drift (p = 0.005), but 74.6% of responses still contain at least one misconception. We conclude by presenting a framework that organizes how students' conceptions of genetic drift change with instruction. We also articulate three hypotheses regarding undergraduates' conceptions of evolution in general and genetic drift in particular. We propose that: 1) students begin with undeveloped conceptions of evolution that do not recognize different mechanisms of change; 2) students develop more complex, but still inaccurate, conceptual frameworks that reflect experience with vocabulary but still lack deep understanding; and 3) some new misconceptions about genetic drift emerge as students comprehend more about evolution.     

Behavioral contrast and responding during multiple food-food,food-water,and water-water schedules

Five pigeons pecked lighted keys for food reinforcers delivered by several multiple variable interval 2-min variable interval 2-min schedules. At different times, the components of the multiple schedule both supplied food reinforcers, both supplied water, or one supplied food and the other supplied water. Rates of responding during the water component of the food-water schedule were lower than the rates during comparable components of the water-water schedules (negative contrast). But, the rates of responding during the food component of the food-water schedule were not greater than the rates of responding during comparable components of the food-food schedules (absence of positive contrast) at two different levels of water deprivation. These results raise questions about several theories of behavioral contrast, and they may restrict the scope of any theory that attributes positive and negative contrast to symmetrical factors.     

A Two-Year Longitudinal Study of Stressful Life Events, Social Support, and Social Problem-Solving Skills: Contributions to Children''s Behavioral and Academic Adjustment

We investigated the contributions of stressful life events and resources (social support and social problem-solving skills) to predicting changes in children's adjustment. At Time 1, 361 third through fifth graders completed measures of social support and social problem-solving skills. Their parents completed a stressful life events scale and a child behavior rating measure. The children's teachers provided ratings of behavioral and academic adjustment. 2-year follow-up data (Time 2) were obtained for approximately half of the sample on the same measures. Time 1 stressful life events and resources showed some significant but modest zero-order correlations with the Time 2 adjustment indices. Hierarchical multiple regressions revealed prospective effects for Time 1 social support on later teacher-rated competencies and grade-point average. In addition, increases over time in social support and social problem-solving skills (a composite score) were significantly related to improvement in behavioral and academic adjustment, whereas stressful life events were not predictive of adjustment.     

Instruction and science learning: A quantitative synthesis

The purpose of this study was to quantitatively synthesize quality and quantity of instruction studies with the same or similar independent variables in the published science education grade 6-12 research of the 1963-1978 period. Fifty-two studies formed six clusters and revealed significant positive cognitive outcomes due to the use of preinstructional strategies, training in scientific thinking, increased structure in the verbal content of materials, and increased realism or concreteness in adjunct materials. In general, systematic innovation in instruction was found to produce positive improvements over the norm or traditional practice. Methodologically, improved research design quality was related to larger effect sizes. Recommendations are made regarding application, use of multiple measures, attitudinal research, use of general education findings, and the reporting of research.     

The chimera of the competency-based approach to teaching mathematics: a study of carpentry purchases for home projects

Educational Studies in Mathematics - The competency-based approach conceives mathematics as a necessary tool for dealing with daily-life tasks. Many studies have focused on examining the low math...     

Working Memory, Motivation, and Teacher-Initiated Learning

Working memory is where we “think” as we learn. A notion that emerges as a synthesis from several threads in the research literatures of cognition, motivation, and connectionism is that motivation in learning is the process whereby working memory resource allocation is instigated and sustained. This paper reviews much literature on motivation and working memory, and concludes that the apparent novelty of the proposal offered to describe motivation in terms of working memory results from the apparent lack of cross-channel exchange among these research traditions. The relation between working memory and motivation is explored in the context of the interactive compensatory model of learning (ICML) in which learning is considered to result from the interaction of ability, motivation, and prior learning. The ICML is recast in light of the revised definition of motivation offered here. This paper goes on to suggest ways in which a range of teaching and learning issues and activities may be reconceptualized in the context of a model emphasizing a learner's working memory that makes use of chunks of previously acquired knowledge.     

Metacognition and Middle Grade Mathematics Teachers: Supporting Productive Struggle

Communicating mathematical ideas through writing, listening, and verbalizing allows students to think about how they “think” about mathematics. By focusing this communication on a reflection of how one thinks about mathematics, metacognitive writing engages students as mathematicians and learners. In this article we describe a professional development that we implemented with middle grade mathematics teachers focused on metacognitive writing as a tool to support productive struggle in the mathematics classroom. Thus, this practitioner article adds to the knowledge base on how to develop middle grade teachers metacognitive writing through engagement in productive struggle. Recommendations for practice are included.     

Ocular dominance,reading and spelling: a reassessment of a measure associated with specific reading difficulties

The association of reading disability with perceptuomotor problems has had a chequered history. This study examines the relationship between a new test of ocular dominance and reading and spelling ability in a group of 323 schoolchildren. Similar rates for unfixed ocular dominance were found for poor readers as in comparable studies. The rates of unstable ocular dominance did not differ between those with reading and spelling difficulties and controls. These findings in a ‘blind’ study question the role of this test of eye dominance as a diagnosis of ‘dyslexia’.