In research concerning model invariance across populations, researchers have discussed the limitations of the conventional chi-square difference test ([Delta] chi-square test). There have been some research efforts in using goodness-of-fit indexes (i.e., [Delta]goodness-of-fit indexes) for assessing multisample model invariance, and some specific…

How this teacher develops composition of ten with second graders was dramatically reshaped by the 2006 release of NCTM's "Curriculum Focal Points." The release of "Curriculum Focal Points"--particularly the suggestion that number sense and computation be focal areas in the second-grade mathematics curriculum--resulted in positive changes in this…

Students will use the first law of thermodynamics to determine the feasibility of using corn ethanol as an alternative to fossil fuels in automobiles. Energy flow is tracked from the Sun, to photosynthesized carbohydrate, to ethanol through fermentation, and finally to work in the combustion engine. Feasibility is gauged by estimating a…

Medicinal chemistry is a specialized, scientific discipline. Computational chemistry and structure-based drug design constitute important themes in the education of medicinal chemists. This problem-based task is associated with structure-based drug design lectures. It requires students to use computational techniques to investigate conformational…

We investigated the influence of self-efficacy beliefs and working memory capacity on mathematical problem-solving performance, response time, and efficiency (i.e., the ratio of problems solved correctly to time). Students completed a letter-recoding task (Experiment 1) or an operation span task (Experiment 2), rated their self-efficacy for…

The European Association for Astronomy Education (EAAE), in collaboration with the Bibliotheca Alexandrina of Egypt and the participation of schools from all around the world, performed the Eratosthenes experiment on 21 June 2010. This activity has been selected as one of the finalists in the 11th international prize organized by Ciencia en…

The relationship between mothers' and teachers' estimations of 60 children's literacy level and their actual performance were investigated in two different socio-economic status (SES) groups: low (LSES) and high (HSES). The children's reading (fluency, accuracy and comprehension) and spelling levels were measured. The mothers evaluated their own…

Continuous exponential families are applied to linking forms via a single-group design. In this application, a distribution from the continuous bivariate exponential family is used that has selected moments that match those of the bivariate distribution of scores on the forms to be linked. The selected continuous bivariate distribution then yields…

A 100 years-old formula that was given by J. J. Thomson recently found numerous applications in computational electrostatics and electromagnetics. Thomson himself never gave a proof for the formula; but a proof based on Differential Geometry was suggested by Jackson and later published by Pappas. Unfortunately, Differential Geometry, being a…

Test security has been a concern for computerized adaptive tests (CAT) due to the nature of continuous testing. This concern becomes unprecedentedly severe with increasingly easy access to the World-Wide-Web where some examinees post on the internet their recollections of items they are administered, leaving future examinees with opportunities to…

I have found that students easily understand that a measurement cannot be exact, but they often seem to lack an understanding of why it is important to know "something" about the magnitude of the uncertainty. This tends to promote an attitude that almost any uncertainty value will do. Such indifference may exist because once an uncertainty is…

The function 1 divided by "x"[superscript 2] minus "e"[superscript"-x"] divided by (1 minus "e"[superscript"-x"])[superscript 2] for "x" greater than 0 is proved to be strictly decreasing. As an application of this monotonicity, the logarithmic concavity of the function "t" divided by "e"[superscript "at"] minus "e"[superscript"(a-1)""t"] for "a"…

In this study, we directly contrast two approaches that have been proposed to explain the SNARC effect. The traditional direct mapping account suggests that a direct association exists between the position of a number on the mental number line and the location of the response. On the other hand, accounts are considered that propose an intermediate…

The achievement level is a variable measured with error, that can be estimated by means of the Rasch model. Teacher grades also measure the achievement level but they are expressed on a different scale. This paper proposes a method for combining these two scores to obtain a synthetic measure of the achievement level based on the theory developed…

The purpose of this study was to examine the impact of misspecifying a growth mixture model (GMM) by assuming that Level-1 residual variances are constant across classes, when they do, in fact, vary in each subpopulation. Misspecification produced bias in the within-class growth trajectories and variance components, and estimates were…