Factor analysis is widely utilized to identify latent factors underlying the observed variables. This paper presents a comprehensive comparative study of two widely used methods for determining the optimal number of factors in factor analysis, the K1 rule, and parallel analysis, along with a more recently developed method, the bass-ackward method.…

Lottery-based identification strategies offer potential for generating the next generation of evidence on U.S. early education programs. The authors' collaborative network of five research teams applying this design in early education settings and methods experts has identified six challenges that need to be carefully considered in this next…

Assessments of natural language can provide vast information about individuals' thoughts and cognitive process, but they often rely on time-intensive human scoring, deterring researchers from collecting these sources of data. Natural language processing (NLP) gives researchers the opportunity to implement automated textual analyses across a…

Research on mathematical cognition, learning, and instruction (MCLI) often takes cognition as its point of departure and considers instruction at a later point in the research cycle. In this paper, we call for psychologists who study MCLI to reflect on the "status quo" of their research practices and to consider making instruction an…

Multilevel structural equation (MSEM) models allow researchers to model latent factor structures at multiple levels simultaneously by decomposing within- and between-group variation. Yet the extent to which the sampling ratio (i.e., proportion of cases sampled from each group) influences the results of MSEM models remains unknown. This paper…

Research questions regarding how, for whom, and where a treatment achieves its effect on an outcome have become increasingly valued in substantive research. Such questions can be answered by causal moderated mediation analysis, which assesses the heterogeneity of the mediation mechanism underlying the treatment effect across individual and…

Nested hierarchical structure is one of life's most familiar properties and a major component of biological diversity and complexity. However, there is little effort to teach the evolution of the hierarchy of life, as there is little effort to teach biological complexity per se. We propose a framework for teaching biological complexity based on…

Researchers strategically assess youth mental health by soliciting reports from multiple informants. Typically, these informants (e.g., parents, teachers, youth themselves) vary in the social contexts where they observe youth. Decades of research reveal that the most common data conditions produced with this approach consist of discrepancies…

Several programs of research have sought to assess the replicability of scientific findings in different fields, including economics and psychology. These programs attempt to replicate several findings and use the results to say something about large-scale patterns of replicability in a field. However, little work has been done to understand the…

The present paper serves as the first systematic review of the training, methodologies, and outcomes reported in the professional development (PD) literature for paraprofessionals working with students with or at risk for externalizing behavior disorders. A total of 16 investigations including 332 paraprofessionals and 852 children and adolescents…