Deck 13: Understanding Research Results: Statistical Inference

Question 1

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

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.

Answer 1

D

Question 2

A researcher was interested in the differences in the opinions about marriage between men and women. She predicted that women would have different opinions about marriage from men. What would the null hypothesis suggest in this situation?

A)Women have more positive opinions about marriage than men.
B)Men have more positive opinions about marriage than women.
C)There is no difference between men and women in their opinions about marriage.
D)There is a difference between men and women in their opinions about marriage.

Answer 2

C

Question 3

The null hypothesis is rejected whenever:

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.

Answer 3

B

Question 4

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:

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 5

Inferential statistics _____.

A)are used to generally describe the data
B)are used to make conclusions about the data
C)focus mainly on scales of measurement
D)focus mainly on standard deviations

Question 6

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.

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

Question 7

According to the _____ hypothesis, the independent variable has no effect.

A)null
B)research
C)practical
D)significant

Question 8

The research hypothesis states that the:

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 9

A researcher studying the gender-based differences in the use of disciplinary practices predicted that men use power-oriented practices more frequently than women. In this case, the research hypothesis would suggest that:

A)women use power-oriented practices more than men.
B)men use power-oriented practices more than women.
C)there is no difference between men and women in the use of disciplinary techniques.
D)gender does not influence the kind of disciplinary practice used.

Question 10

A _____ result is one that has a very low probability of occurring if the population means are equal.

A)simplistic
B)significant
C)specifiable
D)systematic

Question 11

When testing the differences between means, the _____ hypothesis suggests that population means are not equal.

A)null
B)research
C)practical
D)significant

Question 12

Aden finds that, on an average, men have higher starting salaries than women. In order to conclude that the differences in starting salaries are true differences and not a result of random error, Aden would employ the use of _____ statistics.

A)qualitative
B)descriptive
C)inferential
D)ordinal

Question 13

Arafa has collected data on the relationship between physical attractiveness and judgments of personality characteristics. In order to determine if the results obtained from the sample are representative of the population, Arafa will need to employ _____ statistics.

A)qualitative
B)descriptive
C)inferential
D)ordinal

Question 14

The null hypothesis:

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 15

When testing the differences between means, the null hypothesis suggests that any observed difference is due to _____.

A)manipulation
B)systematic variance
C)error variance
D)random error

Question 16

Adrian found no significant difference in the amount of money spent on entertainment on those students who live on campus versus those who live off campus. Based on this finding, Adrian would:

A)accept the null hypotheses.
B)reject the null hypotheses.
C)accept a Type I error.
D)reject a Type I error.

Question 17

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

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 18

According to her statistical analysis, an investigator found that significantly more men than women used punishment to discipline their children. Thus, the investigator would:

A)accept the null hypothesis.
B)reject the null hypothesis.
C)make a Type II error.
D)make a Type I error.

Question 19

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?

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

Question 20

A researcher assesses the length of the prison sentence for physically attractive and physically unattractive defendants. He believes that attractive defendants will receive shorter prison sentences than unattractive defendants. The null hypothesis would suggest that:

A)there is no difference in the length of the prison sentence received by attractive and unattractive defendants.
B)physically attractive defendants will receive longer prison sentences than physically unattractive defendants.
C)physically attractive defendants will receive shorter prison sentences than physically unattractive defendants.
D)some other variable such as gender is responsible for the difference in the length of prison sentence.

Question 21

Before employing inferential statistics, Alberto selects the probability level required for statistical significance. This level is referred to as the _____ of the test.

A)null hypothesis
B)research hypothesis
C)intuitive level
D)alpha level

Question 22

Which of the following accurately describes the relationship between concepts?

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

Question 23

How does sample size affect determinations of statistical significance?

A)The larger the sample size, the greater the probability that the variable has an effect.
B)The smaller the sample size, the greater the probability that the variable has an effect.
C)The larger the sample size, the more accurate the estimation of the true population value.
D)The smaller the sample size, the more confident one can be in one's decision to reject or retain the null hypothesis.

Question 24

The likelihood of the occurrence of some event or outcome is referred to as:

A)reactivity.
B)reliability.
C)variability.
D)probability.

Question 25

The expected value of t under the null hypothesis _____.

A)equals 1
B)equals 0
C)depends on the degrees of freedom
D)varies depending on the alpha level

Question 26

A one-tailed statistical test is used when:

A)the data are from a ratio scale.
B)the data are from an ordinal scale.
C)there is a specific prediction regarding the direction of difference between groups.
D)there is no prediction regarding the direction of difference between groups.

Question 27

A researcher asked participants to rate the quality of two well-known brands of paper bags-Prime and Zenith. Prime was rated higher than Zenith with mean ratings of 5.50 and 3.25 respectively. This difference was statistically significant at the .05 probability level. The research hypothesis for this study suggests that:

A)Prime is better than Zenith in terms of quality.
B)Zenith is better than Prime in terms of quality.
C)There is a difference between Prime and Zenith in terms of quality.
D)There is no difference between Prime and Zenith in terms of quality.

Question 28

When comparing two group means, the _____ refers to the number of scores free to vary once the means are known.

A)null hypothesis
B)research hypothesis
C)statistical significance
D)degree of freedom

Question 29

Alistair has obtained statistical significance in his study that examines the relationship between gender and voter preference. Which statement would Alistair NOT make?

A)Male candidates receive more votes than female candidates.
B)The null hypothesis is rejected.
C)The research hypothesis is accepted.
D)Female candidates are just as likely to receive votes as male candidates.

Question 30

The _____ is commonly used to examine whether two groups are significantly different from each other.

A)t test
B)Mann-Whitney U test
C)Chi-square test
D)r test

Question 31

Statistically, significant results mean that the results are:

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 32

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

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

Question 33

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

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

Question 34

A researcher asked participants to rate the softness of two well-known brands of tissue paper-Daisy and Flora. Daisy was rated softer than Flora with mean ratings of 5.50 and 3.25 respectively. This difference was statistically significant at the .05 probability level. The null hypothesis for the population suggests that:

A)Daisy is softer than Flora.
B)Flora is softer than Daisy.
C)There is a difference between Daisy and Flora in softness.
D)There is no difference between the softness of Daisy and Flora tissues.

Question 35

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 _____.

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

Question 36

A researcher wants to test a hypothesis according to which the mean rating of guilt will be higher for unattractive defendants than for attractive defendants. The appropriate statistical test would be the _____.

A)Pearson r
B)two-tailed t-test
C)one-tailed t-test
D)chi-square

Question 37

A student is interested in the effect of environmental conditions on task performance. She makes participants complete a series of math problems under different conditions of temperature-cold, warm, and hot, and different noise conditions-quiet and noisy. The most appropriate test to analyze the data would be a(n) _____.

A)t-test
B)Pearson r
C)chi-square
D)F-test

Question 38

The larger the F ratio, the more likely the results are _____.

A)significant
B)invalid
C)dissimilar
D)manipulated

Question 39

All statistical techniques rely on _____ to determine the probability that the results are consistent with the null hypothesis.

A)Type I errors
B)Type II errors
C)sampling distributions
D)statistical significance

Question 40

_____ variance is the deviation of the group means from the grand mean.

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

Question 41

The significance level chosen by a researcher is dependent on the _____.

A)scales of measurement used for the study
B)desired probability of correctly rejecting the null hypothesis
C)consequences of making a Type I versus a Type II error
D)type of statistic being used

Question 42

Which significance level would minimize the probability of a Type I error?

A).25
B).10
C).05
D).01

Question 43

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?

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

Question 44

Dr. Afzal finds that students who work less than 10 hours a week have significantly higher test scores than students who work more than 10 hours a week. In order to determine the magnitude of the effect of work hours on test scores, he should calculate an estimate of the _____.

A)critical value
B)effect size
C)null effect
D)halo effect

Question 45

Negative results are problematical because they:

A)are difficult to interpret.
B)are less important.
C)disprove the theory one tries to support.
D)cannot be analyzed statistically.

Question 46

When analyzing the difference between two means, Professor Angus obtains the effect size as .85 using Cohen's d. In this case, Professor Angus can conclude that:

A)85 percent of the effect on the dependent variable is due to the manipulation.
B)there is a correlation of .85 between the independent variable and the dependent variable.
C)the means are separated by a .85 standard deviation.
D)the results would only occur 85 percent of the time.

Question 47

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.

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

Question 48

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

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

Question 49

Reida has developed a program that is designed to increase the reading comprehension scores of sixth graders. She randomly selects three students to participate in her program. When she compares the mean score of the students who completed her program to that of three students who did not participate in the program, she finds no significant difference between the mean scores. What is most likely the reason for the nonsignificant finding?

A)Too strong a manipulation
B)The participation of sixth graders
C)A small sample size
D)A true research hypothesis

Question 50

When the independent variable has no effect on the dependent variable, the effect size statistic will:

A)be equal to the degrees of freedom.
B)have a value of 0.00.
C)have a value of -1.0 or +1.0.
D)vary depending on the alpha level.

Question 51

A consumer analyst asks participants to rate the comfort of the ride for two brands of all-terrain tires-Trail Cushion and Mud Handler. Trail Cushion is rated more comfortable with a mean of 5.5 than Mud Handler, which is found to have a mean of 4.3. The Type I error would be to conclude that Trail Cushion is:

A)more comfortable than Mud Handler when a true difference in comfort exists.
B)no more comfortable than Mud Handler when Trail Cushion is actually more comfortable.
C)no more comfortable than Mud Handler when no difference in comfort exists.
D)more comfortable than Mud Handler when the two tires are equally comfortable.

Question 52

A Type II error occurs when one:

A)rejects the null hypothesis when it is false.
B)rejects the null hypothesis when it is true.
C)accepts the null hypothesis when it is true.
D)accepts the null hypothesis when it is false.

Question 53

Which of the following is the least accurate statement about the use of statistical tests?

A)One of the goals is to allow one to make a decision about whether the obtained results are reliable.
B)The likelihood of obtaining significant results increases with decreasing sample size.
C)The significance level selected indicates how confident one wants to be when making a decision.
D)One is most likely to obtain significant results when the effect size is large.

Question 54

Rejecting the null hypothesis when it is true is called a _____ error, whereas not rejecting a false null hypothesis when it is false is called a(n) _____ error.

A)beta; alpha
B)Type I; Type II
C)minor; major
D)significant; insignificant

Question 55

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.

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

Question 56

The probability of making a Type II error increases when the:

A)significance level is set very high.
B)effect size is small.
C)sample size is large.
D)probability of a Type I error is high.

Question 57

When a researcher _____ the probability of making a Type I error, he or she _____ the probability of making a Type II error.

A)increases; increases
B)decreases; increases
C)decreases; decreases
D)decreases; does not affect

Question 58

According to a survey, 57 percent of the citizens of the United States prefer a Democratic candidate, while 43 percent of the citizens prefer a Republican candidate in an election. The survey reports a confidence interval (CFI) of 95 percent + or -3. What can be concluded from these results?

A)The Republican candidate will win the election.
B)There is a 95 percent chance of making a correct prediction about the election.
C)There is a 5 percent chance of making a correct prediction about the election.
D)There is no way of knowing which candidate has a higher likelihood of being elected.

Question 59

A consumer analyst asks participants to rate the health benefits of two health drinks-EnerG and Supreme. EnerG is rated more nutritive with a mean of 5.5 than Supreme, which is found to have a mean of 4.3. The Type II error would be to conclude that EnerG is:

A)more nutritious than Supreme when a true difference in health benefits exists.
B)no more nutritious than Supreme when EnerG actually provides more health benefits.
C)no more nutritious than Supreme when no difference in health benefits exists.
D)more nutritious than Supreme when the two brands provide similar health benefits.

Question 60

A Type I error occurs when one:

A)rejects the null hypothesis when it is false.
B)rejects the null hypothesis when it is true.
C)accepts the null hypothesis when it is true.
D)accepts the null hypothesis when it is false.

Question 61

A desired probability of correctly rejecting the null hypothesis is the _____.

A)Type I error
B)Type II error
C)effect size of the test
D)power of the test

Question 62

When examining the strength of the relationship between study time and test score, the null hypothesis would suggest that the true population correlation is:

A)greater than 0.00.
B)less than 0.00.
C)equal to 0.00.
D)1.00.

Question 63

The appropriate statistical test for nominal level data of two groups is the:

A)t test.
B)Pearson correlation.
C)chi-square test.
D)analysis of variance.

Question 64

A researcher wants to know if cholesterol levels are lower in vegetarians or nonvegetarians. Which statistical test would be most appropriate for this data?

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

Question 65

The appropriate statistical test for interval or ratio level data is the _____.

A)t test
B)Pearson correlation
C)chi-square test
D)F test

Question 66

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?

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

Question 67

With three independent variables and a single dependent variable, the most appropriate statistical test for analyzing the data would be the _____.

A)chi-square test
B)one-way analysis of variance
C)t test
D)Pearson correlation

Question 68

A manipulation check is especially important when:

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

Question 69

If both the independent and dependent variables use nominal scale properties, the most appropriate statistical test would be the _____.

A)Pearson correlation
B)analysis of variance
C)t test
D)chi-square test

Question 70

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

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