Richard has schizophrenia, At times, he maintains a rigid posture and is unresponsive to vocal commands. At other times, he repeats what other people say to him. Which subtype of schizophrenia does Richard most likely have ?

Factor analysis is a statistical procedure used to:

a. derive IQ scores by comparing mental age with chronological age. b. evaluate how accurately test items predict a criterion behavior. c. extract test norms from a standardization sample. d. identify clusters of closely related test items. e. provide a quantitative estimate of heritability.

Sleep deprivation has been found to interfere with

a. the ability to perform physical tasks. b. the ability to react to stressful situations. c. language abilities. d. the ability to perform tasks that require concentration. e. speech abilities.