The present simulation study indicates that a method where the regression effect of a predictor (X) on an outcome at follow-up (Y1) is calculated while adjusting for the outcome at baseline (Y0) can give spurious findings, especially when there is a strong correlation between X and Y0 and when the test-retest correlation between Y0 and Y1 is…

We introduce the basics of the Monte Carlo method that allows computing areas and definite integrals, by means of the generation of long sequences of random numbers. The areas of some nontrivial shapes are computed, showing the convergence towards their exact values. The application of the method to the computation of definite integrals is also…

The aim of the present study was to investigate the properties of paper-and-pencil data collection instruments developed to measure Computational Thinking (CT) based on several variables. Thus, keywords were identified and used in searches conducted in various databases. The outcomes of the search were analyzed based on the inclusion/exclusion…

Modern environmental science research increasingly requires computational ability to apply statistics to environmental science problems, but graduate students in these scientific fields typically lack these integral skills. Many scientific graduate degree programs expect students to acquire these computational skills in an applied statistics…

Children do not understand the meanings of count words like "two" and "three" until the preschool years. But even before knowing the meanings of these individual words, might they recognize that counting is "about" the dimension of number? Here in five experiments, we asked whether infants already associate counting…

Nomographs (or nomograms, or alignment charts) are graphical representations of mathematical relationships (extending to empirical relationships of data) which are used by simply applying a straightedge across the plot through points on scales representing independent variables, which then crosses the corresponding datum point for the dependent…

We derive formulas for the differential item functioning (DIF) measures that two routinely used DIF statistics are designed to estimate. The DIF measures that match on observed scores are compared to DIF measures based on an unobserved ability (theta or true score) for items that are described by either the one-parameter logistic (1PL) or…

From his first attempts to explain attachment phenomena in the 1940s through his "Attachment and Loss" trilogy (Bowlby, 1969/1982, 1973, 1980), John Bowlby reformulated the theoretical underpinnings of attachment theory several times. He initially attempted to explain attachment phenomena in psychoanalytic terms. Then he invoked…

Regression mixture models are a statistical approach used for estimating heterogeneity in effects. This study investigates the impact of sample size on regression mixture's ability to produce "stable" results. Monte Carlo simulations and analysis of resamples from an application data set were used to illustrate the types of problems that…

Parameter linking in item response theory is generally necessary to adjust for differences between the true values for the same item and ability parameters due to the use of different identifiability restrictions in different calibrations. The research reported in this article explores a precision-weighted (PW) approach to the problem of…

There have been a few methods described in this journal and elsewhere for measuring the wavelength of the standing electromagnetic waves in a microwave oven. Typically, these involve melting chocolate, cheese, or some other substance on a plate that is prevented from rotating. In this article I describe a more dynamic and colorful technique that…

The idea of using fingers as a key component in arithmetic development has received a great deal of support, much of which is based on neuroscientific evidence. However, this body of work pays limited attention to how fingers are used and possible different outcomes in arithmetic problem solving. The aim of our paper, based on an analysis of 126…

We proposed an extended form of the Govindarajulu and Barnett margin of error (MOE) equation and used it with an analysis of variance experimental design to examine the effects of aggregating student evaluations of teaching (SET) ratings on the MOE statistic. The interpretative validity of SET ratings can be questioned when the number of students…

Counting is an important functional skill that is embedded throughout people's daily lives, which can result in numerous meaningful opportunities through which students can learn. Counting, especially early counting, provides a foundation for the development of later mathematics understanding and is highly predictive of later mathematics…

The commenter's proposal may be a reasonable method for addressing uncertainty in predictive modeling, where the goal is to predict "y." In a treatment effects framework, where the goal is causal inference by conditioning-on-observables, the commenter's proposal is deeply flawed. The proposal (1) ignores the definition of…