For each of the following scenarios, identify which research strategy is used: descriptive, correlational, experimental, or non experimental. (Note: For now, do not differentiate between non experimental and quasi-experimental studies. The distinction between them is discussed in Chapter 10.)

a. Dr. Jones conducts a study examining the relationship between viewing violent television and aggressive behavior of 5-year-old boys. Television preferences are obtained by interviewing each child and aggressive behavior is measured by observing the children during an outdoor play period.

b. Dr. Jones conducts a study examining the relationship between viewing violent television and aggressive behavior of 5-year-old boys. Television preferences are obtained by interviewing each child. Based on the interview results, the boys are divided into two groups: those who prefer violent television and those who prefer nonviolent television. Then aggressive behavior is measured by observing the children during an outdoor play period to determine if there is any difference between the two groups.

c. Dr. Jones conducts a study examining the relationship between viewing violent television and aggressive behavior of 5-year-old boys. A group of boys is randomly separated; half the boys are shown violent television programs for 30 minutes before play time and the other half of the boys are shown nonviolent television programs during the same period. Aggressive behavior is then measured by observing the children during an outdoor play period to determine if there is any difference between the two groups.

d. Dr. Jones conducts a study examining aggressive behavior of 5-year-old boys. Each afternoon for 1 week, a group of boys in a child-care center is observed during a 30-minute period while they play outdoors. Aggressive behaviors are recorded during the 30-minute period.