1. The Principle of Parsimony indicates that

1. we should not needlessly complicate the research project
2. we should use the most complex research design possible
3. only one IV should be used in the research project
4. more than one IV should be used in all research projects

1. Random Assignment is more likely to create equal groups when

1. small samples are involved
2. large samples are involved
3. within-subjects comparisons are to be made
4. a directional hypothesis is being tested

1. Your inferential test statistic can be seen to be a ratio or __________ divided by _________.

1. between group variability, within group variability
2. within group variability, between group variability
3. the effect of the DV, the effect of the IV
4. nuisance variables, confounders

1. Error variability for a correlated groups design should be ___________ the error variability for a random

1. the same as
2. more than
3. less than
4. undetermined

1. If you match on an irrelevant variable, the use of the correlated groups design may actually be detrimental

because:

1. a confounder is allowed to operate
2. between group variability increases
3. a nuisance variable is allowed to operate that reduces within groups variability
4. you lose degrees of freedom and a larger critical value is required for the test statistic

1. You decide to use participants’ sex as your IV. Which of the following is true?

1. this will be an ex post facto study
2. this will not be a true experiment
3. you will be unable to draw a cause and effect conclusion
4. all of the above

1. Your IV is sex—comparing men to women. The appropriate statistical test will be

1. correlation
2. t –test
3. ANOVA
4. Z scores

1. Yarbrough (1993) wanted to know if paper color affected survey return rates. The color of paper was

1. a nuisance variable
2. a confounder
3. the DV
4. the IV

1. Suppose you tested the effects of a drug on rats’ learning by giving them 5, 10 or 15 milligrams of the

drug. How many IVs do you have?

1. 1
2. 2
3. 3
4. 4

1. The effect of the IV is contained in

1. within groups variability
2. correlation value
3. error variability
4. between groups variability

1. Unlike the two groups design, a significant result for the multiple groups design requires:

1. many more participants
2. the conduct of post hoc comparisons
3. a manipulated IV
4. a correlation

1. Which of the following is a post hoc test?

1. t- test
2. F- test
3. Scheffe
4. ANOVA

1. You wish to compare the results from three different personality tests. You get three groups of participants

and administer a different test to each group. What analysis should you use?

1. t –test
2. one-way ANOVA
3. two-way ANOVA
4. three-way ANOVA

1. The factorial design gets its name from the use of multiple

1. levels
2. IVs
3. participants per condition
4. control procedures

1. The simplest factorial design is a:

1. 1 X 1
2. 1 X 2
3. 2 X 2
4. 2 X 3

1. A 2 X 2 experiment has been conducted. What information will be obtained from the analysis?

1. the effects of IV A
2. the effects of IV B
3. the effects of A X B
4. all of the above
5. none of the above

1. Which of the following represents a three-way factorial design for an experiment concerning determinants

of GPA?

1. sex (M, F) by major (science, english, education)
2. sex (M, F) by major (science, education)
3. class (Fr. Soph, Jr. Sr) by major (science, math, education)
4. sex (M, F) by class (Fr, Soph, Jr, Sr) by major (science, english, math)

1. When the probability of a result falls between .05 and .10, some researchers say that the result

1. is meaningless
2. fails to show any relationship between the IV and the DV
3. is uninterpretable
4. is marginally significant

1. Making a Type I error means that

1. we rejected the null when we should have accepted it.
2. we accepted the null when we should have rejected it.
3. our IV had an effect on the DV.
4. we allowed an extraneous variable to confound the study.

1. Suppose you are reading an experimental report. What would you know from the following sentence?

1. the interaction of print size and age was significant
2. the interaction of print size and age was not significant
3. the interaction of print size, age, and reading speed was significant
4. the main effects of print size and age were significant

1. Why would you choose to randomly assign participants to groups? Why would you choose to use correlated assignment?

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Explain the matched pairs, repeated measures, and natural pairs techniques. Give an example of an experiment using each.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Explain the rationale behind the use of post hoc comparisons.

1. Correlation (worth 10 points) The number of pounds lost per week and the number of cigarettes smoked per day.

1. What is the null hypothesis ____________________________________
2. What is the significance level_____________
3. What is the correlation value ____________
4. How would you interpret this correlation? ____________________________________________________________________________________________

 

5. What are three explanations for this relationship

• Bonus: If someone said that they conducted a correlation between race of respondent (1 = white, 2 = Asian, 3 = Hispanic, 4 = Black, 5 = other) and income. They found a significant negative correlation. What would you make of this correlation?

Supervisor Bob thinks that workers in his company might work longer hours if he lets them bring in their pets but he wants to know for sure before he allows this in his company. You have been hired to conduct the experiment and your statistician hands you the following printout based on your study. What will you report to Bob concerning his plans?

1. What is the null hypothesis?__________________________________________
2. Will you reject or accept the null?_______________________
3. What will you report to Bob?

________________________________________________________________________________________

 

_____________________________________________________________________________________________

4. How did you assign participants to groups? _________________________

* Bonus: Are there any warnings you might give Bob concerning this study and its implications? (answer on the back)

You are a health psychologist who believes that blood pressure can be influenced by exercise. You conduct an experiment in which you assign subjects to one of two treatment groups based on their weight. Your treatment is the amount of exercise they are told to do for one month (20 vs. 60). Your dependent variable is their blood pressure. What would you conclude from the results given to you by your statistician?

1. What is the null hypothesis for the t-test? _______________________
2. Will you accept or reject this hypothesis? _______________________
3. How would you state your conclusions?

____________________________________________________________________________________________

_____________________________________________________________________________________________

 

4. What specific kind of assignment did you use in this design? ___________________________________________
5. What variable is being controlled in order to reduce error variability ?_____________________________________

You are a consumer psychologist who wants to know if the time of the day makes a difference in how much money consumers spend while in the grocery store. You measure spending at four different times of the day (early morning, midday, afternoon, evening). Your statistician hands you the following printout.

________________________________________________________________________________________________

a. What is the null hypothesis and would you accept or reject it? __________________________________________________________________________________________

b. How would you interpret your findings?

Suppose you believe that working conditions and personality are both related to productivity. You hypothesize that productivity (number of projects completed) is affected by whether or not employees work in closed cubicles or in open spaces where they can talk to one another easily. You also think that whether or not employees are extroverted or introverted will affect productivity. You decide to conduct a 2 X 2 design to test your idea. These are your results.

1. Draw a graph of your findings

 

 

 

 

 

 

 

 

 

 

2. Is there a significant main effect for: Personality _____________ Environment ________________
3. Is the interaction significant? __________
4. How would you interpret the outcome?

________________________________________________________________________________________________

________________________________________________________________________________________________

e. Is this a true experiment? Why or Why not?