Deck 25: Using Statistics to Determine Differences

Question 1

Which of the following are parametric statistical tests that may be used to measure, clarify, or evaluate causation?

A)t-test for independent samples
B)Mann-Whitney U test
C)t-test for dependent samples
D)Wilcoxon signed-rank test
E)ANOVA
F)Tukey Honestly Significant Difference (HSD) test
G)Kruskal-Wallis test
H)Chi-square

Answer 1

t-test for independent samples
t-test for dependent samples
ANOVA
Tukey Honestly Significant Difference (HSD) test

Question 2

What does the two-way chi-square test measure?

A)Whether one variable seems related to another one
B)Whether two variables cause one another
C)Whether an intervention changes the dependent variable's value
D)Change over time

Answer 2

Whether one variable seems related to another one

Question 3

A statistician measures the difference in songbird warble variation in 25 mockingbirds, both before and after nutritional supplementation with Dr. Petit Oiseau's Musical Bird Seed. Warble variation is determined by a cranky librarian, who characterizes the birds, before and after treatment, as one of the following "Lots of Notes There!" "Fair Variety," and "Quite the Redundant Little Song." What considerations determine choice of a test for this research?

A)The sample size is small to moderate.
B)There is one group of birds, and all receive the treatment.
C)A before-after type of design is used.
D)The independent variable is nominal level.
E)Birds are divided into two groups.
F)The dependent variable is ordinal level.
G)The dependent variable is ratio level.

Answer 3

There is one group of birds, and all receive the treatment.
A before-after type of design is used.
The independent variable is nominal level.
The dependent variable is ordinal level.

Question 4

A statistician measures the difference in songbird warble variation in 25 mockingbirds, both before and after nutritional supplementation with Dr. Petit Oiseau's Musical Bird Seed. Warble variation is determined by a computer program that detects sound frequency and pattern changes during a 15-minute period twice a day, and these data are averaged to represent number of warble variations per minute. What considerations determine choice of a test for this research?

A)The sample size is small to moderate.
B)There is one group of birds and all receive the treatment.
C)A before-after type of design is used.
D)The independent variable is at the nominal level.
E)Birds are divided into two groups.
F)The independent variable is ratio level.
G)The dependent variable is ratio level.

Question 5

What are the principal reasons why a nonparametric test of causality is used instead of a parametric one?

A)The assumptions for parametric analyses were not achieved.
B)The effect that the interventional conditions produced was not measurable.
C)The data were not normally distributed.
D)The dependent variable was measured at the ordinal level.
E)The results were not statistically significant.

Question 6

In an ANOVA calculation evaluating causation, the mean square within groups value represents the ordinary amount of variation that exists in the data set. What does the mean square between groups value represent?

A)The effect produced by the interventional conditions
B)The average of all variations in the data set
C)Total variation
D)The differences that exist among the several interventional conditions

Question 7

Below the third table in a research report, concerning switching infants to cow's milk at 6 months of age instead of 12 months, is a notation: "t(22) = -0.76, p = .41" What does this mean?

A)A t-test was performed.
B)Apparently 24 subjects participated in the study.
C)There was a difference between groups.
D)The difference between groups was not statistically significant.
E)If there was an intervention, the intervention was more effective than the control condition.
F)The results are generalizable.
G)The researcher failed to reject the null hypothesis.
H)A Type I error occurred.

Question 8

Which test is essentially a comparison of means?

A)Mann-Whitney U
B)Chi-square
C)Wilcoxon signed-rank test
D)t-test

Question 9

What do the t-test and the ANOVA have in common?

A)They both are used when the dependent variable is ordinal.
B)They both assume a normal distribution.
C)They both compare groups to decide whether they are the same or different.
D)They both can be used when the dependent variable is of the interval level.
E)They both require secondary post hoc analyses.
F)They both use the same statistical tables for interpretation of results.
G)They are both parametric analyses.

Question 10

What is unique about chi-square analysis?

A)It is almost always statistically significant.
B)It is used for two nominal variables.
C)It demands normal distribution, even of dichotomous variables.
D)It is parametric.

Question 11

A researcher is conducting a study to discover whether the provision of hypnosis with dental work affects pain. The researcher's three groups are (1) hypnosis before and during the procedure, (2) hypnosis before but not during the procedure, and (3) no hypnosis. If the researcher plans to use an ANOVA for the statistical analysis, which would be an acceptable way to measure pain, for this study?

A)Present versus absent
B)Worse ... Some ... A Lot ... Unbearable
C)0- to 100-point verbal numerical scale
D)Systolic blood pressure readings
E)The force with which the subject squeezes a rubber ball with pressure gauge attached

Question 12

Which of the following results would represent statistical significance, if the level of significance were set at 0.05 for each?

A)t = 8.43, p < 0.01
B)X² = 10.83, p < 0.1
C)F = 2.37, p < 0.07
D)r = 0.2, p = 0.23
E)r_s = 0.74, p = 0.049

Question 13

Why is post hoc statistical testing not performed with a two-group ANOVA?

A)A researcher is reluctant to perform a post hoc analysis that would require a more stringent level of significance.
B)The F-statistic would be invalidated by the second test.
C)If hypothesis testing reveals that a difference between groups exists, it is obvious what two groups those are.
D)Sample sizes are not large enough for this analysis.

Question 14

A researcher designs a study to measure whether receiving a free season pass to a beautiful ski resort near Bountiful, Utah, increases the number of days a subject who has lived in the area for 1 to 3 years skis during the season. An independent samples t-test of correlation is used to measure the effect of receiving a season pass upon number of ski days. If, instead, the researcher decided to measure the subjects' responses by asking them to check one of these four replies on a survey, "Much more often than last year," "More often than last year," "Just about the same as last year," or "Less often than last year," why would the independent samples t-test have to be abandoned for a Mann-Whitney U test instead?

A)The variable of free season pass versus daily pay is measured at the nominal instead of the ratio level.
B)The variable of free season pass versus daily pay is now measured at the ordinal instead of ratio level.
C)The variable amount skied is now measured at the nominal level instead of the ratio level.
D)The variable amount skied is now measured at the ordinal level instead of the ratio level.
E)Both variables' levels have changed.
F)The independent samples t-test used demands ratio-level or interval-level data.
G)The Mann-Whitney U test allows for ordinal level values, but not nominal.