Under conditions of constant temperature T and pressure P, chemical equilibrium occurs in a closed system (fixed mass) when the Gibbs free energy G of the reaction mixture is minimized. However, when chemical reactions occur under other conditions, other thermodynamic functions are minimized or maximized. For processes at constant T and volume V,…

Digital cameras are a piece of technology routinely used by students. To demonstrate the camera's use as a scientific instrument, the author developed an exercise to challenge students' scientific creativity and provide an experience in the scientific research process. Students designed and carried out experiments to determine the distance from…

In this article a new approach to calculate the return-on-investment (ROI) when introducing technology in education or training is introduced. After an identification of major aspects that are of significance when talking about traditional ROI an alternative method called Simplified ROI is introduced. The main function of Simplified ROI is less to…

Paired associates and serial list memory are typically investigated separately. An "isolation principle" (J. B. Caplan, 2005) was proposed to explain behavior in both paradigms by using a single model, in which serial list and paired associates memory differ only in how isolated pairs of items are from interference from other studied items. In…

An experiment which enables students to determine the index of refraction at various wavelengths is demonstrated by using two polymers examples, poly(dimethyl siloxane) (PDMS) and poly(methyl methacrylate) (PMMA). This experiment would be suitable for a course in organic chemistry or any course discussing the optical properties of polymeric…

Are salary and wage trends in public education keeping up or falling behind in the race with inflation? Are salary increases for central-office administrators and school building administrators keeping pace with increases received by classroom teachers and support personnel? How do overall salary and wage changes in one school system compare with…

In item-response theory, if a latent-structure model has an ability variable, then elementary information theory may be employed to provide a criterion for evaluation of the information the test provides concerning ability. This criterion may be considered even in cases in which the latent-structure model is not valid, although interpretation of…

Full account of the latent regression model for the National Assessment of Educational Progress is given. The treatment includes derivation of the EM algorithm, Newton-Raphson method, and the asymptotic standard errors. The paper also features the use of the adaptive Gauss-Hermite numerical integration method as a basic tool to evaluate…

This paper focuses on using technology to support mathematics instruction. Technologies such as computers and calculators are widely used in the teaching of mathematics. The educators advocate the use of these tools to reduce tiresome computations and tasks so that class time can be more effectively used for learning mathematics. The purpose of…

This article explores the origins and potential benefits of the empty number line for the development of mental computation. It also provides a learner's perspective of its use through the reflections of nine-year-old Emily. (Contains 3 figures.)

Background: Teachers' work overload has been the subject of intense research, and the results of these studies show that a substantial proportion of teachers perceive their job as very stressful. Aims: To investigate how different formulations of high demands and low decision latitude was related to teachers' burnout, and to estimate the possible…

The procedures required to obtain the approximate posterior standard deviations of the parameters in the three commonly used item response models for dichotomous items are described and used to generate values for some common situations. The results were compared with those obtained from maximum likelihood estimation. It is shown that the use of…

This article explores how counting collections of objects helps elementary-age children develop number sense and number relations. The authors provide evidence that counting collections offers multiple entry points for children at different places on the counting trajectory. It is suggested that the teacher's role is one of noticing, questioning,…

This paper describes the construction of a slide-rule computer that allows one to quickly determine magnitudes of several effects that result from the detonation of a nuclear device. Suggestions for exercises are also included that allow high school and college-level physics students to explore scenarios involving these effects. It is hoped that…

In this article, the author describes integrated science and mathematics activities developed for fourth-grade students to explore and investigate three-dimensional geometric shapes, Bernoulli's principle, estimation, and art with and through bubbles. Students were engaged in thinking and reflection on the questions their teachers asked and were…