This article reviews the origins and use of the terms quasi-experiment and natural experiment. It demonstrates how the terms conflate whether variation in the independent variable of interest falls short of random with whether researchers find, rather than intervene to create, that variation. Using the lens of assignment--the process driving…

In this Methods Showcase Article, we outline a workflow for running behavioral experiments online, with a focus on experiments that rely on presentation of complex stimuli and measurement of reaction times, which includes many psycholinguistic experiments. The workflow that we describe here relies on three tools: OpenSesame/OSWeb (open source)…

Understanding the abstract principles of statistical experimental design can challenge undergraduate students, especially when learned in a lecture setting. This article presents a concrete and easily replicated example of experimental design principles in action through a hands-on learning activity for students enrolled in an experimental design…

In particular research domains, the randomized control trial (RCT) is considered to be the only means for obtaining reliable estimates of the true impact of an intervention. However, an RCT design would often not be considered ethical, politically feasible, or appropriate for evaluating the impact of many policy, programme, or structural changes…

In science in general and in the context of single-case experimental designs, replication of the effects of the intervention within and/or across participants or experiments is crucial for establishing causality and for assessing the generality of the intervention effect. Specific developments and proposals for assessing whether an effect has been…

Field experiments, which are a powerful research technique, are common in some fields, but they have not been widely used in studying the effect of financial and counseling planning interventions. Financial services can benefit from the expanded use of field experiments to explore potential causal mechanisms for the effects of financial planning…

Over the last decade, there has been much excitement about the use of optogenetic tools to test whether specific cells, regions, and projection pathways are necessary or sufficient for initiating, sustaining, or altering behavior. However, the use of such tools can result in side effects that can complicate experimental design or interpretation.…

This essay traces the history of an activity designed to promote the intellectual and social development of elementary-age schoolchildren during the afterschool hours. Following in the footsteps of Urie Bronfenbrenner, I highlight his argument that just as all human development occurs in contexts of varying levels of inclusiveness and mutual…

A simple and cheap laboratory class is proposed to illustrate the lethal effect of UV radiation on bacteria and the operation of different DNA repair mechanisms. The class is divided into two sessions, an initial 3-hour experimental session and a second 2-hour analytical session. The experimental session involves two separate experiments: one…

Instructors frequently utilize breaching experiments in an attempt to "bring sociology to life." However, an uncritical embrace of breaching experiments obscures the complexity of their possible effects on participants and subjects. These experiments have real potential to inflict deleterious consequences on individuals and groups.…

Understanding neurocognitive mechanisms in children with autism spectrum disorder (ASD) is an essential goal of autism research. Studying young children with ASD or other neurodevelopmental conditions in demanding experimental settings, however, can pose many practical and ethical challenges. In this article, we present practical strategies that…

It is known that visual working memory capacity is limited, but the nature of this limit remains a subject of controversy. Increasingly, two factors are thought to limit visual memory: an object-based limit associated with so-called "slots" models, and an information-based limit associated with resource models. Recently, Barton, Ester, and Awh…

Covariate adjustment can increase the precision of estimates by removing unexplained variance from the error in randomized experiments, although chance covariate imbalance tends to counteract the improvement in precision. The author develops an easy measure to examine chance covariate imbalance in randomization by standardizing the average…

The subject of research methods is often unknown, foreboding, and unappealing to undergraduate communication majors. Thus, in the research methods course, two ways to overcome such issues and achieve learning are by: (1) making the unfamiliar more familiar and accessible; and (2) placing abstract knowledge in its useful real-world context. Making…

Experiments allow researchers to randomly vary the key manipulation, the instruments of measurement, and the sequences of the measurements and manipulations across participants. To date, however, the advantages of randomized experiments to manipulate both the aspects of interest and the aspects that threaten internal validity have been primarily…