Who is the psychologist that used a pragmatic, trial-and-error approach to psychological measurement that continues to serve as the predominant approach to test construction today?

The current authoritative source for classifying mental disorders is the

a. DSM. b. DSM-III. c. DSM-III-R. d. DSM-IV. e. DSM-IV-TR.

Concrete operational children are able to reverse their thinking, which allows them to perform conservation tasks that preoperational children cannot

Indicate whether the statement is true or false