Question 1

_____ variance is the deviation of the individual scores in each group from their respective group means.

Accepted Answer

A)  Error 
B)  Systematic 
C)  Inferential 
D)  Alpha

Question 2

Which of the following statements is true of a null hypothesis?

Accepted Answer

A)  The population means are not equal. 
B)  The difference in means is not due to random error. 
C)  The mean of the experimental group is not equal to the mean of the control group. 
D)  The mean of the placebo treatment is equal to the mean of the experimental treatment group.

Question 3

The null hypothesis:

Accepted Answer

A)  is used because it is a very precise statement. 
B)  is rejected when there is a high probability that the obtained results are due to random error. 
C)  does not allow one to know the probability of the outcome of the study occurring. 
D)  states that the independent variable did have an effect.

Question 4

When comparing the differences in the ratings of responsibility for an automobile accident between male and female drivers,the null hypothesis would suggest that:

Accepted Answer

A)  women are more responsible drivers than men. 
B)  there is no difference in the ratings of responsibility between male and female drivers. 
C)  men are more responsible drivers than women. 
D)  there is a difference in the ratings of responsibility between male and female drivers.

Question 5

A researcher is interested in knowing whether responses to lowering the legal age for drinking alcohol varies by gender.Which statistical test would be most appropriate for this type of data?

Accepted Answer

A)  Chi-square test 
B)  Analysis of variance 
C)  t test 
D)  Pearson correlation

Question 6

Sean wants to test a hypothesis according to which the mean amount of sales dollars will vary between Oak Ridge,Oak Wood,and Oak Park shopping malls.The appropriate statistical test would be the _____.

Accepted Answer

A)  Mann-Whitney U 
B)  t-test 
C)  F-test 
D)  Pearson r

Question 7

Which statistical test would be most appropriate for examining the relationship between temperature and the number of ice cream cones sold?

Accepted Answer

A)  Chi-square test 
B)  Analysis of variance 
C)  t test 
D)  Pearson correlation

Question 8

If a researcher proposes that there is a difference in the hiring preferences between veterans and nonveterans,such a situation represents the _____ hypothesis.If the researcher proposes that there is no difference in the hiring preferences between veterans and non-veterans,such a situation represents the _____ hypothesis.

Accepted Answer

A)  null;research 
B)  research;null 
C)  inferential;descriptive 
D)  descriptive;inferential

Question 9

Ethan concludes that there is no difference in the driving ability of drivers who have consumed one can of beer and those who have consumed three cans of beer.However,there actually is a difference in the driving ability of the drivers.In this case,Ethan has made a(n)_____ error.

Accepted Answer

A)  null 
B)  alpha 
C)  Type I 
D)  Type II

Question 10

Which of the following is used to determine whether the results held up if an experiment was conducted repeatedly,each time with a new sample?

Accepted Answer

A)  Descriptive statistics 
B)  Inferential statistics 
C)  The research hypothesis 
D)  The null hypothesis

Question 11

The probability of making a Type II error is NOT influenced by the:

Accepted Answer

A)  effect size. 
B)  sample size. 
C)  alpha level. 
D)  gamma level.

Question 12

Which of the following accurately describes the relationship between concepts?

Accepted Answer

A)  Systematic variance = error variance 
B)  Error variance = between-groups variance 
C)  Between-groups variance = systematic variance 
D)  Systematic variance = within-group variance

Question 13

The research hypothesis states that the:

Accepted Answer

A)  independent variable has no effect. 
B)  independent variable has an effect. 
C)  dependent variable has no effect. 
D)  dependent variable has an effect.

Question 14

The sampling distribution is based on the assumption that the _____ hypothesis is _____.

Accepted Answer

A)  null;true 
B)  null;false 
C)  research;true 
D)  research;confounded

Question 15

Tevy reports that individuals who follow her diet plan lose more weight than individuals who follow Jake's diet plan.In actuality,there is no difference in weight loss between those following Tevy's diet plan and those following Jake's diet plan.In this case,Tevy's claim illustrates a _____ error.

Accepted Answer

A)  Type IV 
B)  Type III 
C)  Type II 
D)  Type I

Question 16

A researcher employs inferential statistics to examine the difference in mean scores obtained by fourth grade boys and girls in a standardized math test.In this case,inferential statistics:

Accepted Answer

A)  summarize and describe the important characteristics of the data. 
B)  test the research hypothesis. 
C)  indicate the strength of the relationship between the math scores of boys and girls. 
D)  indicate the probability that the difference between means reflect random error.

Question 17

A manipulation check is especially important when:

Accepted Answer

A)  significant results are obtained. 
B)  nonsignificant results are obtained. 
C)  one-tailed tests are used. 
D)  two-tailed tests are used.

Question 18

The null hypothesis is rejected whenever:

Accepted Answer

A)  past studies prove it wrong. 
B)  there is a low probability that the obtained results could be due to random error. 
C)  the independent variable fails to have an effect on the dependent variable. 
D)  the researcher is convinced that the variable is ineffective in causing changes in behavior.

Question 19

Statistically,significant results mean that the results are:

Accepted Answer

A)  very important. 
B)  meaningless. 
C)  likely to be due to chance differences between the groups. 
D)  likely to be due to true differences between the groups.

Question 20

Andrea is told that the means of two groups in a study were statistically significant.She knows the means and standard deviations of the two groups and is interested in calculating an estimate of effect size.Given this information,which effect size estimate should she calculate?

Accepted Answer

A)  F 
B)  Effect size r 
C)  Cohen's d 
D)  Alpha

Exam 13: Understanding Research Results: Statistical Inference