Item response theory (IRT) procedures have been used extensively to study normal latent trait distributions and have been shown to perform well; however, less is known concerning the performance of IRT with non-normal latent trait distributions. This study investigated the degree of latent trait estimation error under normal and non-normal…

Spontaneous transfer of learning is often difficult to elicit. This finding may be widespread partly because pretests proactively interfere with transfer. To test this hypothesis, 7-year-olds' transfer was examined across 2 numerical tasks (number line estimation and categorization) in which similar representational changes have been observed. As…

This handbook describes the structure and processes that the What Works Clearinghouse (WWC) uses for its reviews, presenting in one place all the standards the WWC currently uses to assess research. The handbook will be revised as new standards are developed and major new features are finalized. A distinguishing feature of the WWC is that it does…

Students served in juvenile correctional school settings often arrive with histories of trauma, aversive educational experiences, low achievement, and other severe risk factors that impeded psychosocial development, educational progress, and occupational outcomes. Schools serving adjudicated youth must address a higher percentage of severe…

Few people realize the impact that high school dropouts have on a community's economic, social, and civic health. Business owners and residents--in particular, those without school-aged children--may not be aware that they have much at stake in the success of their local high schools. Indeed, everyone--from car dealers and realtors to bank…

At the request of Pittsburgh Public Schools (PPS) and the Pittsburgh Federation of Teachers (PFT), Mathematica is developing value-added models (VAMs) that aim to estimate the contributions of individual teachers, teams of teachers, and schools to the achievement growth of their students. The analyses described in this report are intended as an…

Introduction: The cognitive processes that underpin successful mathematical processing in children have been well researched by experimental psychologists, but are not widely understood among teachers of primary mathematics. This is a shame, as an understanding of these cognitive processes could be highly useful to practitioners. This paper…

Logistic regression models of students' 1-year retention and 6-year retention/graduation for the fall 2000 entering class of students at a research-extensive university in the Midwest were estimated by combining university, financial aid, and Cooperative Institutional Research Program data (n = 1,905; 45% female, 87% Caucasian, 75% in-state).…

The contribution of the three core components of working memory (WM) to the development of mathematical skills in young children is poorly understood. The relation between specific WM components and Numerical Operations, which emphasize computation and fact retrieval, and Mathematical Reasoning, which emphasizes verbal problem solving abilities in…

The purpose of this article is to clarify conceptions, definitions, and applications of learning and problem-solving efficiency. Conceptions of efficiency vary within the field of educational psychology, and there is little consensus as to how to define, measure, and interpret the efficiency construct. We compare three diverse models that differ…

A rapid serial visual presentation (RSVP) technique was used to investigate the role of the nature of processing carried out on targets in the Lag-1 sparing phenomenon. Lag-1 sparing refers to a higher accuracy in the task associated with the 2nd target when the 2 targets are immediately successive in the RSVP stream relative to when there are 1…

The purpose of this paper is to present the types of measures that may be used to describe intervention effects from single subject designs. A regression approach and several non-regression approaches are described. Non-regression approaches include Standard Mean Difference, Percentage of Non-Overlapping Data, Percent Reduction, and Percentage…

It has been claimed that recursion is one of the properties that distinguishes human language from any other form of animal communication. Contrary to this claim, a recent study purports to demonstrate center-embedded recursion in starlings. I show that the performance of the birds in this study can be explained by a counting strategy, without any…

Although statistical procedures are well-known for comparing hierarchically related (nested) mean and covariance structure models, statistical tests for comparing non-hierarchically related (nonnested) models have proven more elusive. Although isolated attempts at statistical tests of non-hierarchically related models have been made, none exist…

With its critical assessments of scientific evidence on the effectiveness of education programs, policies, and practices (referred to as "interventions"), and a range of products summarizing this evidence, the What Works Clearinghouse (WWC) is an important part of the Institute of Education Sciences' strategy to use rigorous and relevant…