In the Context of the Historical Development of Single-Subject Designs

Multiple Choice

In the context of the historical development of single-subject designs, which of the following took place at the beginning of the 20^th century?

A) A global measurement of therapeutic effectiveness was found to be inappropriate because of the overwhelming complexity and number of confounding variables.
B) The first experiments were performed on individual subjects.
C) Awareness of the inadequacies of the uncontrolled case study led to the existence of the therapeutic professions being challenged.
D) The invention of descriptive and inferential statistics facilitated group comparisons.