Exam 8: Issues in Inferential Statistics

In a particular study, a directional hypothesis was stated. (The researchers hypothesized that Group A would score significantly higher than Group B.) When the data were analyzed, the mean scores for Group A and Group B were 37 and 40, respectively. What should the researcher do now?

How many total subjects are needed in a 2 x 2 repeated-measures design with 10 subjects in each treatment condition?

Which of the following describes a mixed-model design?

Given the following information, would you reject the null hypothesis? t df Sig (2-tailed) Mean Diff 2.65 123 .03 4.8

In a study of IQ scores, if the mean score and standard deviation for the control group are 100 and 15, respectively, and the researcher has decided not to do an experiment unless an effect size of at least 1.00 can be achieved, what minimum IQ score would the treatment group need to reach?

What do statistically significant results imply?

An experimenter using the .05 alpha level determined that two means were not significantly different. In actual fact, the null hypothesis is false. What error has been committed, and what were the chances of its occurrence?

Which of the following statements correctly indicates the relationship between statistical significance and practical significance?

Which of the following is NOT a definition of statistical power?

Which of the following correctly indicates that a one-tailed test will be used?

What name is given to the condition in an experimental design where the same subjects are in every group?

What has happened when a researcher rejects H₀ when H₀ is false?

You reported a relationship that really does not exist. What did you do?

If a researcher accepts a false null hypothesis, what has occurred?

Use the following information to answer the question: The purpose of the research was to determine whether cholesterol level is related to lifestyle behaviors. The lifestyle behaviors of interest were physical activity, dietary fat intake, smoking status, and self-reported life satisfaction. The researchers rejected the null hypothesis. What was the primary dependent variable in this study?

In a 2 x 4 between-groups design, how many total subjects are needed if 10 subjects are required for each group?

If a researcher retains the null hypothesis, but it is false, what error has been committed, and what is its probability? (α = .05)

If α = .05 and β = .90, what is the power?

A decrease in which of the following will generally increase power?

How many independent variables exist in a 2 x 3 x 4 experimental design?