When one has many intervention studies conducted on a single topic, we may want to pool the results:
- Meta-analysis lets us pools results across studies to obtain estimates of overall efficacy
- Meta-regression lets us answer further questions about variation in efficacy.
- For example, "Do the results vary in relation to…"
- Features of the participants in the experiment (e.g., children, teenagers)
- Dosage (e.g., weeks)
- Outcomes measured (e.g., total math, subscale scores, science)
- Study design (e.g., RCT, quasi-experiment)