Related Experiment Video
Updated: May 22, 2025
10:26
Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
Published on: September 11, 2021
3.8K
Synthesizing data from pretest-posttest-control-group designs in mediation meta-analysis.
Zhiming Lu1, Zijun Ke2, Rebecca Y M Cheung3
1Department of Psychology, Sun Yat-Sen University, Guangzhou, Guangdong, China.
Behavior Research Methods
|April 15, 2025
Summary
This study validates mediation meta-analysis (MMA) for pretest-posttest-control-group (PPCG) designs, comparing posttest scores (PSMMA) and change scores (CSMMA) for effect size computation. Results support MMA feasibility under PPCG designs.
Area of Science:
- Psychology
- Statistics
- Research Methodology
Background:
- Mediation meta-analysis (MMA) under pretest-posttest-control-group (PPCG) designs faces validity concerns.
- Issues include structural equation modeling with binary independent variables, varied treatment doses, and violated variance assumptions.
Purpose of the Study:
- To address concerns regarding MMA in PPCG designs.
- To compare effect size computation using posttest scores (PSMMA) versus change scores (CSMMA).
- To demonstrate the feasibility of MMA under PPCG designs.
Main Methods:
- Theoretical discussions.
- Monte Carlo simulations to assess MMA validity and compare PSMMA and CSMMA.
- Summarization of effect size computation procedures.
Main Results:
- Demonstrated the feasibility of conducting mediation meta-analysis under PPCG designs.
- Provided a comparison between PSMMA and CSMMA effect size calculations.
- Addressed concerns related to binary independent variables and heterogeneous treatment doses.
Conclusions:
- Mediation meta-analysis is feasible for pretest-posttest-control-group designs.
- The choice between PSMMA and CSMMA depends on specific study characteristics.
- Guidelines for effect size computation in MMA for PPCG designs are presented.
Keywords:
Analysis, PretestControlGroup designMediation metaPosttestSynthesizing mediating mechanismsMore Related Videos
Related Concept Videos
02:01Group Design
8.9K
The most basic experimental design involves two groups: the experimental group and the control group. The two groups are designed to be the same except for one difference— experimental manipulation. The experimental group gets the experimental manipulation—that is, the treatment or variable being tested—and the control group does not. Since experimental manipulation is the only difference between the experimental and control groups, we can be sure that any differences between...
8.9K
01:50Statistical Significance
20.1K
Once data is collected from both the experimental and the control groups, a statistical analysis is conducted to find out if there are meaningful differences between the two groups. A statistical analysis determines how likely any difference found is due to chance (and thus not meaningful). In psychology, group differences are considered meaningful, or significant, if the odds that these differences occurred by chance alone are 5 percent or less. Stated another way, if we repeated this...
20.1K
01:16Experimental Designs
11.0K
An experimental design is a systematic process that allows researchers to evaluate the relationship between dependent and independent variables. There are three widely used types of experimental design - pre-experimental design, true experimental design, and quasi-experimental design. In pre-experimental design, the researcher compares the data before and after some interventions or treatments. The true-experimental design has more than one purposefully created group, a commonly measured...
11.0K
01:15Study Design in Statistics
7.8K
A study design is a set of techniques that allow a researcher to collect and analyze data from different variables defined for a specific research problem. Statistics is commonly for effective study design and more robust experiments,
Does aspirin reduce the risk of heart attacks? Is one brand of fertilizer more effective at growing roses than another? Is fatigue as dangerous to a driver as the influence of alcohol? Questions like these are answered using randomized experiments with proper...
Does aspirin reduce the risk of heart attacks? Is one brand of fertilizer more effective at growing roses than another? Is fatigue as dangerous to a driver as the influence of alcohol? Questions like these are answered using randomized experiments with proper...
7.8K
01:16Crossover Experiments
2.7K
Crossover experiments, also called the repeated-measurements design, is a study design in which all experimental units are exposed to all treatments in different periods. Crossover experiments are generally used in psychology, the pharmaceutical industry, agriculture, and medicine.
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
2.7K
01:13Controls in Experiments
6.9K
When conducting an experiment, it is crucial to have control to reduce bias and accurately measure the dependent variables. It also marks the results more reliable. Controls are elements in an experiment that have the same characteristics as the treatment groups but are not affected by the independent variable. By sorting these data into control and experimental conditions, the relationship between the dependent and independent variables can be drawn. A randomized experiment always includes a...
6.9K