Answer the same six questions for each of the experiments described below:

1. Identify any subject variable(s).

2. Identify the independent variable(s).

3. Identify the design (e.g., one way, 2 X 2 factorial).

4. Identify the number of conditions for each independent and manipulated variable.

5. Identify the total number of conditions.

6. Is this a repeated measures design or a between subjects design?

7. Identify the dependent variable(s).

Design 1:

A researcher interested in weight control wondered whether normal and overweight individuals differ in their reaction to the availability of food. Thus, normal and overweight subjects were told to eat as many peanuts as they desired while working on a questionnaire. One manipulation was the proximity of the peanut dish (close or far from the subject); the second manipulation was whether the peanuts were shelled or unshelled. After filling out the questionnaire, the peanut dish was weighed to determine the amount of peanuts consumed.

Design 2:

A researcher studied the influence of intensity of room illumination (low, medium. and high) on reading speed among fifth graders. Each child read 750-word passages under all three levels of illumination (three reading trials). The order of trials for each child was randomly determined.

Design 3:

A researcher investigated the effect of a child’s hair length on judgments of personality and intelligence. Teachers were shown photographs of children to obtain their first impressions of the children. The researcher chose pictures showing different lengths of hair to be shown to the teachers. Each teacher was shown a boy or girl whose hair was either very short, shoulder length, or very long. Teachers rated the friendliness of the child and estimated the child’s intelligence level.

Design 4:

An investigator was interested in the effects of various treatments on reduction of fear in phobic subjects. He suspected that type of phobia may interact with therapeutic treatments; specifically, that the types of treatments for agoraphobics (fear of open spaces) and claustrophobics (fear of closed spaces) might be different. He divided subjects into two groups based upon type of fear and then assigned members of each group to treatment groups: desensitization, insight, and implosive therapies. After three months of treatment, subjects’ anxiety in the feared situation was measured.

Design 5:

Subjects participated in a driving simulation study to investigate night-driving reactions as a function of alcohol consumption and road conditions. Subjects drank cocktails containing either no alcohol, 3 ounces of alcohol, or 6 ounces of alcohol. After 30 minutes, they began the driving simulation test. Each subject simulated a drive on either a straight road, a road with gentle curves, or a road with many sharp curves and on which the subjects encountered various road hazards such as oncoming cars or construction crews. The number of accidents was measured for each subject.

Design 6:

To assess the effects of room illuminations on recognition, forty-eight participants, randomly selected from the undergraduate subject pool at Austin Peay University were randomly assigned to one of four groups with the restriction that the sample sizes would be equal. Treatment one, the control, was defined by the standard level of room illumination prescribed for new classroom construction. Treatments two, three, and four represented equal increments in illumination up to a level where the cost factor (including power) would restrict further consideration. Participants were tested using a speed recognition test. They were asked to type the word they saw flashed on the computer screen onto the keyboard. They were given 30 random target words and the number of correct responses was recorded.

Design 7:

A random selection of nine students from the undergraduate subject pool at Boise State University were tested under two experimental conditions. Under the first condition, no music was playing while participants were asked to identify a word as it was briefly flashed (i.e., 200 ms.) on a computer screen by typing the word onto the computer keyboard as quickly as possible after the word was flashed. Under the second condition, participants were asked to complete the same task, however, noise in the form of hard rock music (i.e., Pearl Jam’s “Jeremy”) was playing loudly (i.e., 30 db.) in the background. Each condition included 15 trials (i.e., words) before switching the treatment condition. Order of treatment was counterbalanced across participants. Two measures, correct responses and reaction time (ms. to the first letter typed) were recorded.

Design 8:

We designed the present study to address the effects of three different dosages of acetylcholine and difficulty of memory tasks in the ability to remember in Alzheimer’s patients. Thirty Alzheimer adults (; ; mean of years) participated in this study. The two difficulty levels of memory task were: 1) low – remember their name and 2) high – remembering a series of tasks to perform within the next hour. The three levels of drug dosage used were 1) 5 mg., 2) 10 mg., and 3) 20 mg. Participants were randomly assigned to level of drug dosage, but all participants completed both difficulty levels with the order counterbalanced across subjects. Ability to remember was measured as the number of correct responses.