Purpose: Among the gold standards in human resource development (HRD) research are studies that test theoretically developed hypotheses and use experimental designs. A somewhat typical experimental design would involve collecting pretest and posttest data on individuals assigned to a control or experimental group. Data from such a design that…

Over many decades, educators have developed countless interventions and theories about how to create lasting change. Implementation research is the study of these efforts with a set of basic questions: What are we doing? Is it working? For whom? Where? When? How? And, Why? In other words, implementation research is an endeavor to understand if and…

A subset of students fail to respond adequately to reading interventions. This synthesis systematically reviews studies in which students in grades K-3 responded inadequately to a Tier 2 reading intervention and were provided with a Tier 3 intervention. Descriptions of the Tier 3 reading interventions and effects are provided. To meet inclusion…

In experimental research, internal validity refers to what extent researchers can conclude that changes in dependent variable (i.e. outcome) are caused by manipulations in independent variable. The causal inference permits researchers to meaningfully interpret research results. This article discusses (a) internal validity threats in social and…

Reporting standards and critical appraisal tools serve as beacons for researchers, reviewers, and research consumers. Parallel to existing guidelines for researchers to report and evaluate group-comparison studies, single-case experimental (SCE) researchers are in need of guidelines for reporting and evaluating SCE studies. A systematic search was…

Early detection methods for autism spectrum disorder (ASD) in infancy are rapidly advancing, yet the development of interventions for infants under two years with or at-risk for ASD remains limited. In order to guide research and practice, this paper systematically reviewed studies investigating interventions for infants under 24 months with or…

This systematic descriptive historical review was conducted to examine the status and trends in expository text structure instruction efficacy research for first through twelfth grade students. The analysis included sixty studies, which spanned the years 1978 to 2014. Descriptive dimensions of the research included study type, research design,…

This article examines changes in the research design, sample size, and precision between the planning phase and implementation phase of group randomized trials (GRTs) funded by the Institute of Education Sciences. Thirty-eight GRTs funded between 2002 and 2006 were examined. Three studies revealed changes in the experimental design. Ten studies…

This meta-analysis examined the influence of attributes related to the implementation of learning strategy instruction interventions on students' academic performance, and also examined how the attributes related to the method of testing the intervention effects affected the actual effects measured. Using metaregression, we analyzed the…

Experimental designs are distinguished as the best method to respond to questions involving causality. The purpose of the present paper is to explicate the logic of experimental design and why it is so vital to questions that demand causal conclusions. In addition, types of internal and external validity threats are discussed. To emphasize the…

This comparative study was designed to investigate how online and traditional face-to-face (FtF) students used different learning styles in a graduate educational course. A nonequivalent control group design was employed. The study involved 19 students in an experimental group (online section) and 25 students in a control group (FtF section) in a…

The Hawthorne and placebo effects in educational experiments were examined over a 20-year period, as reported in the ERIC, Dissertation Abstracts International, and Psych Info data bases. The literature searches identified 325 studies in education employing the relevant control procedures, and each study was coded for the type of placebo…

The effect size was calculated for 104 dependent variables studied in 23 experimental or quasi-experimental evaluations of patient education programs. The mean effect size for all 23 studies indicated that the average taught patient moved from the 50th to the 77th percentile, relative to the control group. (GDC)

Several recent studies are identified that used expert ratings of the job performance of certified professionals as a validation criterion. These studies showed a strong relationship between expert ratings and certification, but were susceptible to alternative interpretations due to design constraints. Inclusion of control constructs is presented…

A review and meta-analysis were made of placebo control groups in educational experiments. In all, 125 studies were clustered into procedures that included (1) explicit manipulation of attentional elements; (2) explicit description of the placebo activity plus implied reference to attention; and (3) exclusive reference to the activity. (SLD)