1. To assess the effect of caffeine on persistence researchers assign their participants to a group that gets a non-caffeinated beverage or a group with a caffeinated beverage. They measure how much time the participants spend on a difficult puzzle.
2. To see whether intelligence is important for academic success, researchers look at the relation between scores on an intelligence test and grade point average.
3. In investigating the factors related to marital satisfaction, a researcher asks 300 married adults how long they have been married and how satisfied they are with their marriage.
4. Believing men tend to be more adventurous than women a researcher asks 100 men and 100 women to rate themselves on adventurousness.
5. A college wonders if off-campus experiences are helpful in promoting critical thinking so they survey all of the students who spent a semester abroad and all the students who stayed on campus to assess critical thinking skills. This is an quasi-experiment because you are promoting critical thinking which can only be found by having the student study abroad. The dependent variable is semester abroad students and independent is the students who stayed on campus.
6. To investigate whether individuals will be more interested in being with other people when they are in a stressful situation, a researcher told half of their participants that they would be giving an impromptu speech (a stressful situation) and the other half that they would be writing a short essay on a well-known topic (a non-stressful situation). He