Experimental designs in the social sciences have received increasing attention due to their power to produce causal inferences. Nevertheless, experimental research faces limitations, including limited external validity and unrealistic treatments. We propose combining qualitative fieldwork and experimental design iteratively--moving back-and-forth…

As evidence-based reform becomes increasingly important in educational policy, it is becoming essential to understand how research design might contribute to reported effect sizes in experiments evaluating educational programs. The purpose of this study was to examine how methodological features such as types of publication, sample sizes, and…

Both true experiments and regression discontinuity (RD) designs produce unbiased estimates of effects. However, true experiments are, of course, often criticized on equity grounds, whereas RD designs entail sacrifices in terms of statistical precision. In this article, a hybrid of true experiments and RD designs is considered. This hybrid entails…

This article presents a cohesive, empirically grounded categorization system differentiating the types of generalizations students constructed when reasoning mathematically. The generalization taxonomy developed out of an empirical study conducted during a 3-week teaching experiment and a series of individual interviews. Qualitative analysis of…

To investigate the generalizability of the results of single-case experimental studies, evaluating the effect of one or more treatments, in applied research various simultaneous and sequential replication strategies are used. We discuss one approach for aggregating the results for single-cases: the use of hierarchical linear models. This approach…

The purpose of this paper is to offer insights from scholarly literature, related theory, and practical activities that can inform leaders' efforts to allocate resources and create incentives that will result in powerful, equitable learning for all. This document: (1) sketches the context for work and research related to resource allocation…

The Prime Minister's Committee on Natural Science in Education in Great Britain reported in 1918 that "...in many schools more time is spent in laboratory work than the results obtained can justify." Seventy years later this conclusion can often still be drawn. This is particularly a problem in open distance education where laboratory practicals,…

The purpose of this study was to determine the concerns of Texas science teachers about the 40 percent laboratory time rule just prior to enforcement and at the end of its first year of implementation. The methodology, results of the first and second years, conclusions, and implications for teaching science are discussed. (KR)

Discusses an analysis of the relationship of soil temperatures at 3 depths to various climatic variables along a 200-kilometer transect in west-central Oklahoma. Reports that temperature readings increased from east to west. Concludes that temperature variations were explained by a combination of spatial, temporal, and biophysical factors. (SG)

Explains the characteristics and importance of random assignment in experimental research on education. Considers factors supporting causal inferences, the nature of "assignment units," differences between random sampling and random assignment, the characteristics of randomization tests, forms of random assignment, and effects of experimental…

The approach of J. D. Sneed is used to argue for a distinction between theoretical and nontheoretical (or empirical) entities. Attention is directed toward this approach as an important facility for looking at statistics and for constructing a framework for the correct use of statistical theory in information retrieval experiments. (MBR)

Investigates strategies of 10-year-olds and 14-year-olds in tasks requiring prospective memory. Subjects were instructed to perform activities after waiting 30 minutes. As predicted, strategic time-monitoring occurred more frequently in the home than in the laboratory. Emphasizes the power of the laboratory as a contrasting context for…

Reviews a study which sought to obtain a quantitative metabolic map of the neurons mediating a specific memory. Research results support notions of cooperative processes in which nonrandom behavior of high ensembles of neural elements mediates the integration and processing of information and the retrieval of memory. (ML)

Self-efficacy, or a person's perception of his/her own mastery of a skill, affects subsequent task performance and predictions of future performance. To examine older adults' metamemorial knowledge with respect to predicting their performance on everyday and laboratory memory tasks, 28 adults (22 females, 6 males), aged 58 to 80 years, completed a…

This investigation showed no sex difference between boys and girls with regard to practical work at the end of their first year of secondary school and no difference between schools and groupings (all boys, all girls, mixed schools with mixed science classes, and mixed schools with single sex science classes). (JN)