One concern with measuring split-half reliability is that many different correlations are possible depending on how you decide to split the test items in half

An epidemiologist is about to testify to Congress on the findings of comorbidity. Which of the following points will she want to make after reviewing research on comorbidity?

a. Most mental disorders have a biological basis. b. Those with severe impairment often have more than one disorder. c. We have underestimated the role of toxins as the cause of disorders. d. The majority of mental disorders tend to "run in families" as a result of genetic anomalies.

The slot machine is an example of a variable-ratio schedule.

a. true b. false