We use a natural experiment to show that the presence of an external examiner has both a direct and an indirect negative effect on the performance of monitored classes in standardized educational tests. The direct effect is the difference in the test performance between classes of the same school with and without external examiners. The indirect…

In this article we introduce language acquisition researchers to two broad areas of applied statistics that can improve the way data are analyzed. First we argue that visual summaries of information are as vital as numerical ones, and suggest ways to improve them. Specifically, we recommend choosing boxplots over barplots and adding locally…

On the basis of those respondents in the National Longitudinal Survey of Youth (NLSY) who change jobs with an intervening period of education reinvestment, the conventional assumption of linearity of log wages in years of schooling is strongly rejected: a typical reinvestment for the 1980 through 1993 period is associated with a rise of about 3.5…

Temperament has a long history of scholarship dating back as early as 350 BC when Hippocrates (1984) associated body fluids or temperament with behavior. Temperament is broadly described as stylistic and relatively stable traits that subsume intrinsic tendencies to act and react in somewhat predictable ways to people, events, and other stimuli.…

This study serves as a teaching aid for teachers of introductory statistics. The aim of this study was limited to determining various sample sizes when estimating population proportion. Tables on sample sizes were generated using a C[superscript ++] program, which depends on population size, degree of precision or error level, and confidence…

Of the several measures of optimism presently available in the literature, the Life Orientation Test (LOT; Scheier & Carver, 1985) has been the most widely used in empirical research. This article explores, confirms, and cross-validates the factor structure of the Chinese version of the LOT with ordinal data by using robust weighted least…

Confidence intervals (CIs) and effect sizes are essential to encourage meta-analytic thinking and to accumulate research findings. CIs provide a range of plausible values for population parameters with a degree of confidence that the parameter is in that particular interval. CIs also give information about how precise the estimates are. Comparison…

This article evaluates the impact and cost-effectiveness of offering an innovative middle school model--the Sistema de Aprendizaje Tutorial (SAT)--to Honduran villages instead of traditional middle schools. We identified a matched sample of villages with either type of school and collected baseline data among primary school graduates eligible to…

As all physicists know, all units are arbitrary. The numbering system is anthropocentric; for example, the Celsius scale of temperature has 100 degrees between the boiling point of water at STP and the freezing point of water. The number 100 is chosen because human beings have 10 fingers. The best units might be based on physical constants, for…

Nairne, Thompson, and Pandeirada (2007) discovered a strong and rather general memory advantage for word material processed in a survival-related context. One possible explanation of this effect conceives survival processing as a special form of encoding: Nature specifically "tuned" our memory systems to process and remember…

School voucher and education tax credit programs have proliferated in the United States over the past two decades. Advocates have argued that they will enable families to become active consumers in a free and competitive education marketplace, but some fear that these programs may in fact bring with them a heavy regulatory burden that could stifle…

Systematic reviews are used to inform practice, and develop guidelines and protocols. A questionnaire to quantify the risk of bias in systematic reviews, the review paper assessment (RPA) tool, was developed and tested. A search of electronic databases provided a data set of review articles that were then independently reviewed by two assessors…

Standardized-test scores are increasingly important indicators of school success. But how robust are school-performance ratings when they are based on measures derived from these scores? In my thesis, using data from Houston Independent School District (HISD) and New York State (NYS), I examined the robustness of school-performance ratings across…

Existing research shows that house prices respond to local school quality as measured by average test scores. However, higher test scores could signal better quality teaching and academic value-added, or higher ability, sought-after intakes. In our research, we show decisively that value-added drives households' demand for good schooling. However,…

Purpose: Adults with language-based disabilities are known to have deficits in oral language; however, less is known about their written language skills. Two studies were designed to characterize the writing of adults with language-based disabilities. Method: In Study 1, 60 adults, 30 with language impairment and 30 with typical language,…