Which of the following refers to a measured variable used to determine whether the manipulation has unwittingly caused differences on other variables that might be systematically related to the independent variable?

Which is NOT true of our self-image?

a. It is almost never influenced by stranger's opinions. b. Teasing by family members can lead to a negative self-image. c. We tend to revise our self-image through more recent experiences with others. d. Youth tend to internalize what others think of them.

Suppose you conduct a survey of 100 teenage girls, asking them whether or not they used contraception at their first experience of sexual intercourse

If this group was typical, you should expect that about ____ of these girls report that they DID use contraception. a. 90% b. 78% c. 50% d. 22%