Research Designs provides a short overview of the principles involved in the design of experimental and non-experimental studies. Included are single groups designs, pretest-posttest designs, factorial designs, and hierarchical designs. Strengths and weaknesses of the various designs are covered. This book is Volume 22 of Sage Publishing’s Quantitative Applications in the Social Sciences, often referred to as the “little green books”. I wrote this one and Summated Rating Scale Construction.