Six-year-old Amira received a score of 30 on an intelligence test, and this was the average score received by most 10-year-olds. Amira's mental age would be considered

One of the main concerns with the case study method of research is that

a. a single case is seldom able to provide a historical perspective. b. hypotheses cannot be generated about the origin of the behavior. c. case studies cannot be used to study rare or unusual events. d. the experiences reported may be highly subjective.

A threat to internal validity in which extreme scores, upon retesting, tend to be less extreme is called a. a time-series confound

b. a single-group effect. c. regression to the mean. d. none of the options is correct