I was recently asked the following question about experimental research, and I am copying my answer here, in case it is of interest to readers of the blog:
When can we omit or not use the control group in our research and we can use more than one experimental group instead? Sometimes we have to do this in Education. When and why?
It is indeed possible to do research with two or more experimental groups and no control group, but there are some caveats.
In education research, a study with more than one experimental groups would be appropriate when we want to compare the effects of variables with multiple values: e.g., syllabuses, teaching methods or approaches, etc. Provided that our sample is large enough, and group membership is assigned randomly, we can assume that all the experimental groups are more-or-less similar in most respects. If we then applied a…
View original post 463 more words