The structure, development, and etiology of observed temperament during middle childhood.

Investigating the structure and etiology of temperament is key to understanding how children interact with the world (Kagan, 1994). Although these topics have yielded an abundance of research, fewer studies have employed observational data during middle childhood, when unique environmental challenges could influence temperament development. To address this gap, Israeli twin children were observed at Age 6.

General Ability or Distinct Scholastic Aptitudes? A Multidimensional Validity Analysis of a Psychometric Higher-Education Entrance Test.

The present study explored the construct validity of the Psychometric Entrance Test (PET) for higher education in Israel, as represented by the factorial structure of the scholastic aptitudes it measures, and focused on whether the test presents a single measure of overall ability or a measure of the fields of knowledge that are being tested. In Study 1, we used Exploratory Factor Analysis to generate hypotheses regarding the factorial structure of the test. In Study 2, Confirmatory Factor Analysis was carried out to compare competing models that were constructed based on theoretical considerations and the results of Study 1.

Standard errors and confidence intervals for correlations corrected for indirect range restriction: A simulation study comparing analytic and bootstrap methods.

A frequent topic of psychological research is the estimation of the correlation between two variables from a sample that underwent a selection process based on a third variable. Due to indirect range restriction, the sample correlation is a biased estimator of the population correlation, and a correction formula is used. In the past, bootstrap standard error and confidence intervals for the corrected correlations were examined with normal data.