what is a randomized group design?

Angel Klym: here are some links:http://core.ecu.edu/psyc/wuenschk/docs2210/Researc...Experimental designs are often touted as the most "rigorous" of all research designs or, as the "gold standard" against which all other designs are judged. In one sense, they probably are. If you can implement an experimental design well (and that is a big "if" indeed), then the experiment is probably the strongest design with respect to internal validity. Why? Recall that internal validity is at the center of all causal or cause-effect inferences. When you want to determine whether some program or treatment causes some outcome or outcomes to occur, then you are interested in having strong internal validity. Essentially, you want to assess the proposition:http://www.socialresearchmethods.net/kb/desexper.p...good luck!....Show more