1. Factorial designs are used when the researcher wishes to measure the effect of an independent variable __________.
2. Most people thrive on a diet containing phenylalanine; only the rare people with
phenylketonuria suffer brain damage because of it. This is an example of a(n):
3. In a factorial design, subjects are matched on IQ and then one of each pair is randomly assigned to one of the treatments; the design is a __________.
4. The design that best controls for individual differences between subjects, using the fewest number of subjects, is the __________.
5. In a between-subjects design, a possible threat to internal validity is _________.
6. A __________ design is a design with two or more independent variables, in which the complete set of treatments is defined by the product of the levels of the independent variables.
7. In a __________ design, each subject receives all the treatments; in a _________ design, each subject receives only one treatment.
8. An experiment with two independent variables, each of which has two levels, in which all
combinations of treatments are included, is called a(n) ________ design.
9. In a factorial design, the total number of treatments __________.
10. In Hall and Kataria's study evaluating different treatments for attention deficit hyperactive disorder, the children were tested on a delayed response task both when they were taking Ritalin and when they were not. A variable such as this involving repeated testing of the same subjects is called:
11. A researcher investigates the effect of caffeine on problem solving speed. She administers either a placebo, 1, 2, or 5 mg of caffeine to subjects and measures the average time it takes them to solve three problems. This design contains _______________ factor(s) with __________ level(s).
12. Counterbalancing is a technique that can be used for:
