Read the research study description and then answer the questions that follow the description.

Researchers in Dublin, Ireland, carried out a study on the effects of a Self-Alert Training (SAT) program in adults with ADHD. The participants were randomly assigned to either the SAT or control training. One of the psychological outcome measures was the Beck Depression Inventory (BDI). The BDI contains 21 questions about the severity of depression symptoms. Test takers are asked to rate each question on a scale of 0 to 3 where higher scores indicate higher depression. The Elevator Counting with Distraction was used to assess sustained attention. For this test, the test takers listened to a series of tones and counted the high pitched tones only. The post-training results indicated that the SAT group had significantly lower BDI scores than the control group. The post-training results also showed that the SAT group’s improvement on the Elevator Counting with Distraction test was significantly greater than the control group’s improvement.

1. The investigators carried out an ___.

a. Experiment

b. Observational study

2. A Beck Depression Inventory (BDI) score is a ___ variable.

a. Qualitative

b. Quantitative

3. Depression is measured on the ___ level.

a. Nominal

b. Ordinal

c. Approximately interval

d. Interval/Ratio

4. An Elevator Counting with Distraction test score is a ___ variable.

a. Qualitative

b. Quantitative

5. Depression is a/an ___ variable.

a. Dependent

b. Independent

6. Group assignment (SAT or control) is a/an ____ variable.

a. Dependent

b. Independent