. What are the limitations of each of the specific designs?

A. (a) A single group post-test only design

(b) single group pretest/posttest design really lacks a decent sized comparison group which can lead to being completely unsure if the changes from the pretest are a result of the in between work done that lead to a posttest result.

(c) single-group time-series design

(d) nonequivalent control group posttest-only design

(e) nonequivalent control group pretest/posttest design

(f) multiple-group time-series design