The usual formula for variance depending on rounding off the sample mean lacks precision, especially when computer programs are used for the calculation. The well-known simplification of the total sums of squares does not always give benefit. Since the variance of two observations is easily calculated without the use of a sample mean, and the…

This article describes a simple way to demonstrate powder diffraction in a classroom setting using a dry film of spherical colloids on a glass substrate. Use of transparent, elastomeric poly(dimethylsiloxane) as a supporting substrate for the spheres rather than glass enables demonstration of the reciprocal lattice effect. (Contains 4 figures and…

Purpose: Family caregivers comprise the backbone of long-term-care provision in the United States, yet little is known about how the composition and experience of family caregiving has changed over time. Design and Methods: Data are drawn from the 1989 and 1999 National Long-Term Care Survey and Informal Caregiver Survey to develop nationally…

This paper explores the wide range of mathematics content and processes that arise in the secondary classroom via the use of unusual counting problems. A universal pedagogical goal of mathematics teachers is to convey a sense of unity among seemingly diverse topics within mathematics. Such a goal can be accomplished if we could conduct classroom…

In the IEA PIRLS International Report, a number of indices of reading-related constructs were introduced for the purpose of explaining the variation in reading achievement. These indices, however, raise issues of reliability and validity, due to the way in which they are derived and due to the quality of the data. Targeting these issues, the…

In 2 experiments with 74 high school students, subjects studied worked examples while learning how to translate English expressions into algebraic equations. Those using worked examples outperformed the control group on posttests, made fewer errors, completed work more rapidly, and required less assistance from the teacher. (SLD)

In this paper, a data perturbation method for minimizing the possibility of disclosure of participants' identities on a survey is described in the context of the National Assessment of Educational Progress (NAEP). The method distinguishes itself from most approaches because of the presence of cognitive tasks. Hence, a data edit should have minimal…

This study provides estimates of the private Internal Rates of Return (IRR) to tertiary education for women and men in 21 OECD countries, for the years between 1991 and 2005. IRR are computed by estimating labour market premia on cross-country comparable individual-level data. Labour market premia are then adjusted for fiscal factors and education…

Through her work as a consultant, Burns has found that a handful of students in all classes lack an adequate foundation in basic math concepts and lag far behind their peers in both understanding and skills. Students who lack a foundation on which to build new learning are generally not well served even by well-planned, differentiated instruction;…

Objective: Compare observed and forecasted efficacy of mixed amphetamine salts extended release (MAS-XR; Adderall) with atomoxetine (Strattera) in ADHD children. Method: The authors analyze data from a randomized, double-blind, multicenter, parallel-group, forced-dose-escalation laboratory school study of children ages 6 to 12 with ADHD combined…

The present study assesses the population prevalence of DSM-IV disorders among native and immigrant children living in low socio-economic status (SES) inner-city neighborhoods in the Netherlands. In the first phase of a two-phase epidemiological design, teachers screened an ethnically diverse sample of 2041 children aged 6-10 years using the…

The aim of this study was to ascertain the nature of the interaction between the affective value of musical distraction, personality type and performance on the cognitive tasks of reading comprehension, free recall, mental arithmetic and verbal reasoning in children aged 11-12 years. It was hypothesized that the cognitive performance of extraverts…

This article describes a joint effort between a mathematics educator and a middle school art teacher who wanted their students to experience first hand how construction works in the real world. It starts with students designing and building scale models for a large inflatable item in which they display their art and extends to building the…

This article describes a lesson study project that explored the impact of using storybooks to teach mathematics in three kindergarten classrooms. The study involved three kindergarten teachers and three university educators, who collaborated to plan, design, implement revise, and reflect on a unit of mathematics that focused on the concept of…

Many people believe that the 1989 National Council for Teachers of Mathematics (NCTM) standards heralded the biggest mathematics reform of the 20th century. Despite all reform efforts, recent studies indicate that mathematics taught in primary and middle school mainly consists of basic arithmetic tasks that use memorization and repetition. Today…