The world is facing complex global societal challenges including accelerating climate change, a pandemic, rising social inequalities also in well-functioning welfare states, cultural and linguistic diversity, and a renewed call for racial justice. Developmental psychology can make strong contributions to address these and other global challenges…

In this study, we re-analyze recent empirical research on replication from a meta-analytic perspective. We argue that there are different ways to define "replication failure," and that analyses can focus on exploring variation among replication studies or assess whether their results contradict the findings of the original study. We…

Researchers often rely on undergraduate students to participate in psychological studies and so ethical guidelines state that there must be educational value to their participation. In previous studies that have asked undergraduates whether they felt they learned something new from participating in research, students have generally said yes.…

The central roles of science in the field of remedial and special education are to (a) identify basic laws of nature and (b) apply those laws in the design of practices that achieve socially valued outcomes. The scientific process is designed to allow demonstration of specific (typically positive) outcomes, and to assist in the attribution of…

Planned missing data designs allow researchers to increase the amount and quality of data collected in a single study. Unfortunately, the effect of planned missing data designs on power is not straightforward. Under certain conditions using a planned missing design will increase power, whereas in other situations using a planned missing design…

This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have…

Latent state-trait (LST) analysis is frequently applied in psychological research to determine the degree to which observed scores reflect stable person-specific effects, effects of situations and/or person-situation interactions, and random measurement error. Most LST applications use multiple repeatedly measured observed variables as indicators…

Donald Campbell's approach to causal inference (D. T. Campbell, 1957; W. R. Shadish, T. D. Cook, & D. T. Campbell, 2002) is widely used in psychology and education, whereas Donald Rubin's causal model (P. W. Holland, 1986; D. B. Rubin, 1974, 2005) is widely used in economics, statistics, medicine, and public health. Campbell's approach focuses on…

In this commentary, we demonstrate how the potential outcomes framework can help understand the key identification assumptions underlying causal mediation analysis. We show that this framework can lead to the development of alternative research design and statistical analysis strategies applicable to the longitudinal data settings considered by…

This article compares Donald Campbell's and Donald Rubin's work on causal inference in field settings on issues of epistemology, theories of cause and effect, methodology, statistics, generalization, and terminology. The two approaches are quite different but compatible, differing mostly in matters of bandwidth versus fidelity. Campbell's work…

In recent years, single-case designs have increasingly been used to establish an empirical basis for evidence-based interventions and techniques in a variety of disciplines, including psychology and education. Although traditional single-case designs have typically not met the criteria for a randomized controlled trial relative to conventional…

What are the common pitfalls experienced by school researchers and how can they be avoided? Edited by Lisa M. Dinella of Monmouth University, "Conducting Science-Based Psychology Research in Schools" includes the collective knowledge of both established and emerging names in the field, providing an unparalleled resource for those interested in…

Multisite research designs involving cluster randomization are becoming increasingly important in educational and behavioral research. Researchers would like to compute effect size indexes based on the standardized mean difference to compare the results of cluster-randomized studies (and corresponding quasi-experiments) with other studies and to…

Statistical reform in school psychology research is discussed in terms of research designs, measurement issues, statistical modeling and analysis procedures, interpretation and reporting of statistical results, and finally statistics education.

The movement toward evidence-based treatments, interventions, or practices pressures single case research (SCR) to use statistical summaries which have broad credibility. These summaries also need to be easily understood and useful in schools and clinics. To date the effect size families, "proportion of variance"…