In confirmatory factor analysis (CFA), model parameters are usually estimated by iteratively minimizing the Maximum Likelihood (ML) fit function. In optimal circumstances, the ML estimator yields the desirable statistical properties of asymptotic unbiasedness, efficiency, normality, and consistency. In practice, however, real-life data tend to be…

Synthesis of (Z)-alkenes is challenging because the (E) stereoisomers are usually more stable. Energy transfer photocatalysis has emerged as an efficient strategy for (E) [right arrow] (Z) alkene isomerization. We report the development of an advanced undergraduate laboratory experiment that introduces students to contemporary organic…

Low test-taking effort of examinees has been considered a source of construct-irrelevant variance in item response modeling, leading to serious consequences on parameter estimation. This study aims to investigate how non-effortful response (NER) influences the estimation of item and person parameters in item-pool scale linking (IPSL) and whether…

Computational thinking (CT) is increasingly integrated into education, promoting problem-solving skills essential for the 21st century. However, little is known about how teachers assess CT in K-12 classrooms. This qualitative study explores elementary teachers' approaches to CT assessment after professional development in integrating CT into core…

A readily and widely applicable procedure is discussed that can be used to point and interval estimate the probabilities of particular responses on polytomous items at pre-specified points along underlying latent continua. The items are assumed thereby to be part of unidimensional multi-component measuring instruments that may contain also binary…

Bell's theorem is a topic of perennial fascination. Publishers and the general public have a steady appetite for approachable books about its implications. The scholarly literature includes many analogies to Bell's theorem and simple derivations of Bell inequalities, and some of these simplified discussions are the basis of interactive web pages.…

Infants who receive better counting input at home tend to become toddlers with better number knowledge in preschool. However, for many children, in-person counting experience is not always available, despite educational media becoming increasingly prevalent. Might virtual counting experience benefit the young mind? Using a novel online looking…

The use of the aggregate scoring method for scoring concordance tests requires the weighting of test items to be derived from the performance of a group of experts who take the test under the same conditions as the examinees. However, the average score of experts constituting the reference panel remains a critical issue in the use of these tests.…

Computational thinking skills are thought to have a significant part in almost every area and profession in the future. Yet, there is no sufficient number of studies in the literature to understand computational thinking and to reveal its nomological network. Therefore, the purpose of this study was to determine the relations between preservice…

The aim of the present study is to explore strategies in enumerating units of three dimensional (3D) arrays. We analyse enumeration strategies of students in grade 3 (ages 8 to 9) in situations of cubical and spherical representations of units of 3D arrays. By exploring students' strategies in these two situations, we find that difficulties in…

This paper examines the implementation of unplugged tasks across different school settings developing computational thinking skills and concepts at upper primary school children in Spain without programming and without using electronic devices. The study is based on qualitative case study design. Across the three case studies/schools --…

This article is concerned with a subset of numerically stable and scalable algorithms useful to support computationally complex psychometric models in the era of machine learning and massive data. The subset selected here is a core set of numerical methods that should be familiar to computational psychometricians and considers whitening transforms…

A reference interval, or an interval in which a prespecified proportion of measurements from a healthy population are expected to fall, is used to determine whether a person's measurement is typical of a healthy individual. For a specific biomarker, multiple published studies may provide data collected from healthy participants. A reference…

The relativistic addition of velocities is usually introduced early in the study of Einstein's special theory of relativity. The equations are simple enough, but randomly chosen velocities lead to unwieldy calculations that can dishearten the student. This paper presents tables of velocity components in two dimensions, composed of five or fewer…

In learning to program and understanding how a programming language controls a computer, learners develop both insights and misconceptions whilst their mental models are gradually refined. It is important that the learner is able to distinguish the different elements and roles of a computer (compiler, interpreter, memory, etc.), which novice…