Parallel analysis (PA) assesses the number of factors in exploratory factor analysis. Traditionally PA compares the eigenvalues for a sample correlation matrix with the eigenvalues for correlation matrices for 100 comparison datasets generated such that the variables are independent, but this approach uses the wrong reference distribution. The…

This meta-analysis reviewed 144 studies from 1996 to 2013 using the Beck Depression Inventory-Second Edition. Internal consistency was 0.89 and test-retest reliability 0.75. Convergent comparisons were robust across 43 depression instruments. Structural validity supported both one- and two-factor solutions and diagnostic accuracy varied according…

The purpose of this inquiry was to investigate the effectiveness of item response theory (IRT) proficiency estimators in terms of estimation bias and error under multistage testing (MST). We chose a 2-stage MST design in which 1 adaptation to the examinees' ability levels takes place. It includes 4 modules (1 at Stage 1, 3 at Stage 2) and 3 paths…

Data distributions can be represented using different external representations, such as histograms and boxplots. Although the role of external representations has been extensively studied in mathematics, this is less the case in statistics. This study helps to fill this gap by systematically varying the representation that accompanies a task…

Regression discontinuity design is an alternative to randomized experiments to make causal inference when random assignment is not possible. This article first presents the formal identification and estimation of regression discontinuity treatment effects in the framework of Rubin's causal model, followed by a thorough literature review of…

This article presents a reanalysis of the data of 862 second and fourth graders collected in two previous studies, focusing on the influence of method (psychometric vs. chronometric) and stimulus type on the gender difference in mental-rotation accuracy. The children had to solve mental-rotation tasks with animal pictures, letters, or cube…

Errors in detecting randomness are often explained in terms of biases and misconceptions. We propose and provide evidence for an account that characterizes the contribution of the inherent statistical difficulty of the task. Our account is based on a Bayesian statistical analysis, focusing on the fact that a random process is a special case of…