Subhotosh, it only mentions the definitions of within-subjects design and matched-subjects designs. It doesn't talk about the similarities and differences. The within-subjects design is defined as, "A type of correlated-groups design in which the same subjects are used in each condition." The matched-subjects design is defined as, "A type of correlated groups design in which subjects are matched between conditions on variable(s) that the researcher believe is (are) relevant to the study." My textbook is not very good when giving explanations on material or going into detail about the terms.