A quantitative analysis method which aggregates a number of (similar) individual studies into a large data set from which to compute an over all “effect size” (based on similar study procedures and treatments) is commonly known as…?

The quantitative analysis method commonly known as aggregating a number of similar individual studies into a large data set to compute an overall "effect size" is called a meta-analysis.

The quantitative analysis method which aggregates a number of similar individual studies into a large data set to compute an overall "effect size" is commonly known as a meta-analysis.

If you want to know the answer to this kind of question in the future, you can do a simple internet search using keywords related to the topic. In this case, you could search for "quantitative analysis method that aggregates similar studies to compute effect size." This will most likely lead you to reliable sources, such as academic journals or research articles, which can provide a more detailed explanation and examples of meta-analysis.