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…

Until now, the conventional approach using two distinct groups, experimental and control, continues to dominate research, especially education research. Researchers, particularly those who are active in this domain, readily recognise this pattern when surveying literature. This article explores the use of the Solomon four-group design as a…

The recognition that researcher discretion coupled with unconscious biases and motivated reasoning sometimes leads to false findings ("p-hacking") led to the broad embrace of study preregistration and other open-science practices in experimental research. Paradoxically, the preregistration of quasi-experimental studies remains uncommon…

In recent years, countries including the UK and USA have seen advancements in the use of Randomised Controlled Trials in education, progress that has not been mirrored in Ireland. Ireland does not have a strong tradition of using experimental or quasi-experimental evaluation designs for monitoring and evaluation of education policy despite…

This paper introduces a simple, quotient effect size, termed (for 'quotient'), suitable for reporting on the effectiveness of educational interventions. The quotient effect size for a pre-test-post-test design is defined as the gain score (i.e. post-test minus pre-test) for the intervention group, divided by the gain score for the control group.…

The distribution of the standardized mean difference is well understood. However, in many situations, researchers need to estimate an effect size to represent the relationship between a continuous outcome and a dichotomous grouping variable, adjusting for the effect of a covariate (or a set of covariates). Typically, this adjustment takes place…

This Case Study reviews a quasi-experimental research project in the field of the scholarship of teaching and learning. Researching the effects of pedagogic interventions poses a number of methodologic challenges. Our original research goal was to create an assignment that would ameliorate the problem of content knowledge loss. Teaching and…

The randomized control trial (RCT) is the primary experimental design in education research due to its strong internal validity for causal inference. However, in situations where RCTs are not feasible or ethical, quasi-experiments are alternatives to establish causal inference. This paper serves as an introduction to several quasi-experimental…

Interrupted time series (ITS) studies are frequently used to examine the impact of population-level interventions or exposures. Systematic reviews with meta-analyses including ITS designs may inform public health and policy decision-making. Re-analysis of ITS may be required for inclusion in meta-analysis. While publications of ITS rarely provide…

Scholarly efforts to identify core design features for effective teacher professional development have grown rapidly in the last 25 years. Many concise lists of design principles have emerged, most of which converge on a consensus of 5-7 presumably 'effective' features (e.g. collaborative tasks, active learning, focus on content). The…

We are sometimes forced to use the Interrupted Time Series (ITS) design as an identification strategy for potential policy change, such as when we only have a single treated unit and cannot obtain comparable controls. For example, with recent county- and state-wide criminal justice reform efforts, where judicial bodies have changed bail setting…

Background: Painting is the foundational expression across all art forms and is one of the key creative practices for fostering students' aesthetic ability and creativity within fine arts courses. Collaborative painting in the form of socially shared regulation of learning (SSRL) can be recognized as an effective strategy for enhancing creativity…

This essay imagines how the "quasi-philosophy" of Alfred Jarry (1873-1907) might function as a fulcrum for overturning the legacy of "standard" thinking and writing now profuse within the Educacene, or rather, the epoch of globalized educational standardization. This essay will consider how Jarry's pataphysics or "science…

Quasi-experimental methods are a cornerstone of applied social science, providing critical answers to causal questions that inform policy and practice. Although open science principles have influenced experimental research norms across the social sciences, these practices are rarely implemented in quasi-experimental research. In this paper, we…

By design, randomized experiments (XPs) rule out bias from confounded selection of participants into conditions. Quasi-experiments (QEs) are often considered second-best because they do not share this benefit. However, when results from XPs are used to generalize causal impacts, the benefit from unconfounded selection into conditions may be offset…