In an Experiment, Extraneous (Nonmanipulated) Variables Are Controlled By

Multiple Choice

In an experiment, extraneous (nonmanipulated) variables are controlled by:

A) having more than one experimenter interact with all subjects in the study
B) using subjects who are similar to each other in nearly all respects
C) making all aspects of the procedure identical for all conditions, except for the independent variable manipulation
D) the assignment of subjects to experimental conditions based on the characteristics of the subjects