Suggests an elementary school activity and questions to promote five types of mathematical thinking including modeling, logical analysis, inference, optimization, and abstraction. Discusses evaluating activities for mathematical reasoning opportunities. (ASK)

Investigated the robustness of the group-level polytomous Item Response Theory model to violations of assumptions of school-level normality and within-school normality and constant variance with eight large simulated case samples. Discusses the precision obtained in estimating school ability. (SLD)

Describes an investigation that leads to one of the significant contributions that sabermetrics--new approaches to gaining information about baseball from its numerical records--has made to our understanding of baseball. (ASK)

Examines the importance of declining economic conditions in school attendance decision making for households with teenagers aged 12-17 in Costa Rica, using a reduced-form model. The 1981-83 economic recession coincided with a large attendance drop. Household labor market characteristics and student characteristics also significantly determine…

The intention of this article is to present a year-long interdisciplinary course, Mathematical Models in Chemistry. The course is comprised of eleven units, each of which has both a mathematical and a chemical component. A syllabus of the course is given and the format of the class is explained. The interaction of the professors and the content is…

In recent years, latent class models have proven useful for analyzing relationships between measured multiple indicators and covariates of interest. Such models summarize shared features of the multiple indicators as an underlying categorical variable, and the indicators' substantive associations with predictors are built directly and indirectly…

Switch costs in task switching are commonly attributed to an executive control process of task-set reconfiguration, particularly in studies involving the explicit task-cuing procedure. The authors propose an alternative account of explicitly cued performance that is based on 2 mechanisms: priming of cue encoding from residual activation of cues in…

A novel attentional capture effect is reported in which visual-verbal serial recall was disrupted if a single deviation in the interstimulus interval occurred within otherwise regularly presented task-irrelevant spoken items. The degree of disruption was the same whether the temporal deviant was embedded in a sequence made up of a repeating item…

The use of complex value-added models that attempt to isolate the contributions of teachers or schools to student development is increasing. Several variations on these models are being applied in the research literature, and policy makers have expressed interest in using these models for evaluating teachers and schools. In this article, we…

Time delays are an important aspect of mathematical modelling, but often result in highly complicated equations which are difficult to treat analytically. In this paper it is shown how careful application of certain undergraduate tools such as the Method of Steps and the Principle of the Argument can yield significant results. Certain delay…

The difficulties that primary students experience when dealing with real-world related word problems have been discussed extensively. These difficulties are not only related to complex, non-routine problems but already occur with respect to routine problems that involve the application of a simple algorithm. Due to difficulties with the…

Binary or graded disagree-agree responses to attitude items are often collected for the purpose of attitude measurement. Although such data are sometimes analyzed with cumulative measurement models, recent investigations suggest that unfolding models are more appropriate (J. S. Roberts, 1995; W. H. Van Schuur and H. A. L. Kiers, 1994). Advances in…

This paper outlines a theoretical perspective for studying student understandings of the concept of addition. The notion of operational sense is defined as a way to describe the notion of addition as a mathematical object, paving the way for an application of the theory of reification at this level. Previous frameworks relative to problem solving…

The concept of fuzzy time series is introduced and used to forecast the enrollment of a university. Fuzzy time series, an aspect of fuzzy set theory, forecasts enrollment using a first-order time-invariant model. To evaluate the model, the conventional linear regression technique is applied and the predicted values obtained are compared to the…

The objective of this investigation was to take a small data set that represents unbalanced factorial designs and explain by example how the variance is partitioned when using the various options from the Statistical Package for the Social Sciences (SPSSX) and Statistical Analysis System (SAS). That the unequal cell size analysis of variance…