A research design in which someone tests a claim about a variable by exposing a person to the variable and showing that the person thought, felt, or behaved as expected is referred to as:

You are watching a video of a man in a developing country performing a task intended to determine if he is in the formal operations state of development. The person performing the task is 28 and he is performing quite poorly. What explanation would late 20th-century researchers have given to account for his poor performance?

a. He was cognitively incapable of formal operations. b. He did not have formal education that included the scientific method. c. He had previously experienced brain damage. d. He was not interested in "proving" his abilities.

The average age of menarche in the United States is _____ years of age

a. 6-8 b. 8-9 c. 10-11 d. 12-13