Last test
If the correlation between two variables is 0.40, what is its r2 (coefficient of determination)?
0.16
Consider a two-way ANOVA. Factor A has three categories and Factor B has four categories. How many groups are defined by these two factors?
12
Consider a three-way ANOVA. Factor A has three categories, Factor B has four categories, and Factor C has two categories. How many interaction effects are there in all?
4
A total of 75 nursing students take a professional board preparation course, and 65 other nursing students study on their own. Which test could be used to reveal which group had the higher board scores, assuming the board scores were normally distributed?
A - independent t test
Which test would be most appropriate to answer the following research question: Are women who are treated at a public health department with a dual diagnosis of unplanned pregnancy and sexually transmitted disease (STD) younger than those who have an unplanned pregnancy but do not have an STD? There were 250 women in the study, and their ages were normally distributed.
A - independent test
Which test would be most appropriate to answer the following research question: Is there a difference in the mean weight loss by women in two age groups (18 to 44 years and 45 to 64 years) over a 3-month period? There were 87 women in the sample, and weight loss was normally distributed.
A - independent test
Which test would be most appropriate to answer the following research question: Is there a difference in the number of outpatient medical visits a year between people who live in urban areas and those who live in rural areas? There were 22 people in the sample (half in each group), and the number of visits was normally distributed.
A - independent test
Consider the following question: Do people without health insurance spend more money a year on over-the-counter drugs than people who have some form of health insurance? How many levels (or possible values) does the variable "health insurance" have?
Two
Consider the following question: Is there a relationship between insurance status and the number of days absent from work? To use an independent t test, how many possible values should the variable "health insurance" have?
Two
The paired t test is used to determine whether the means of which of the following are different from one another?
Two repeated measures and measures from a case and a matched control
Do sixth-graders differ in their knowledge of healthy eating before and after an intervention to teach good nutrition? Knowledge is measured by a 20-item quiz. The sample contains 102 students, and the data (knowledge of healthy eating) are not normally distributed.
Wilcoxon matched pairs test
Patients in a critical care unit, who are matched on age, receive either experimental oral care or control oral care. Which test would be most appropriate to answer the following research question: Does the type of oral care received by the patients have any effect on their length of stay in the critical care unit? There were 36 pairs of patients, and their length of stay was not normally distributed.
Wilcoxon matched pairs test
What is the average number of times per month people exercised before and after a 3-hour exercise orientation program? The study includes 17 participants, and the data (number of times people exercised) are not normally distributed.
Wilcoxon matched-pairs test
Which of the following statistical tests can be used if the data are paired but normally distributed in only one of the measures being compared?
Wilcoxon matched-pairs test
The Friedman's ANOVA by rank is
a nonparametric test
The Kruskal-Wallis test is
a nonparametric test
The Mann-Whitney U-test is best described as
a nonparametric test
The repeated-measures ANOVA is
a parametric test
The independent samples t test is best described as
a parametric test.
The paired t test is
a parametric test.
The main difference between N-way ANOVA and MANOVA is
b & c that ANOVA models have only one dependent variable that MANOVA models can have more than one independent variable
Data are considered paired if
both a and b are true
Friedman's ANOVA by rank has which of the following characteristics?
both a and b are true
The Wilcoxon matched-pairs test is most likely to be significant when
both b and c are true
If the ANOVA test is significant, the next step would be to
conduct a post hoc test to determine which mean(s) are significantly different from the others
Conducting a MANOVA is advantageous to an ANOVA if the outcome measures are
correlated
Which type of variable is included in ANCOVA but not in ANOVA?
covariate
A study is conducted to see whether back pain is best treated by chiropractic interventions, medication, surgery, or no intervention. The chiropractic intervention group has 24 people, the medication group has 17 people, the surgery group has 14 people, and the no intervention group has 18 people. These data include
four independent measures of the same variable
How do people rate their mood (1 to 10, with 1 = very unhappy to 10 = ecstatic) while sitting in five differently colored rooms (i.e., blue, orange, green, purple, and red)? Each person sits in each room and then rates his or her mood. The sample contains 16 people, and the data (mood rating) are not normally distributed.
friedman ANOVA by rank
What are the preferences for contraceptive methods among college freshmen (i.e., no contraception, condoms, injected medoxyprogesterone (Depo-Provera), or birth control pills)? Each student ranks the methods from 1 to 5, with 5 being the most desirable. The sample contains 22 students.
friedman ANOVA by rank
All the following are assumptions for the N-way ANOVA except
heterogeneity of variance
The one-way ANOVA is best used when the measurement scale of the characteristic of interest is
interval or ratio
The paired t test is best used when the measurement scale of the characteristic of interest is
interval or ratio
The repeated-measures ANOVA is best used when the measurement scale of the characteristic of interest is
interval or ratio
Student's independent samples t test is best used when the measurement scale of the characteristic of interest is
interval or ratio.
All ANOVA models determine whether there is a difference in the ______ of different groups.
means
Which of the following measures of central tendency are tested by the Wilcoxon matched-pairs test to determine whether two groups are significantly different?
medians
N-way ANOVA models require that independent variables generally are
nominal
The Mann-Whitney U-test is best used when the measurement scale of the characteristic of interest is
ordinal and interval or ratio.
The Wilcoxon matched-pairs test is best used when the measurement scale of the characteristic of interest is
ordinal and interval or ratio.
All the following are elements needed to compute the f-ratio for each of the factors and for the interaction term in an N-way ANOVA except
p-value
Do women diagnosed with gestational diabetes consume fewer grams of carbohydrates each day than do other pregnant women? A study was conducted with 130 women with gestational diabetes and 130 nondiabetic pregnant women. The women were matched on age, ethnicity, and number of prior pregnancies. Data on grams of carbohydrate consumed in the week before the 7-month prenatal visit were obtained from both groups. The data (grams of carbohydrate consumed) are roughly normally distributed.
paired t test
In a twin study of infant sucking behavior, one infant is shown pictures of faces, and the other is shown pictures of random geometric shapes. Which test would be most appropriate to answer the following research question: Do the infants who are shown the faces evidence more vigorous sucking behavior? There were 38 pairs of infants, and sucking frequency was normally distributed.
paired t test
Do workplace wellness programs increase exercise rate? A workplace wellness program enrolls 452 participants. The number of minutes a week that the participants exercise is measured weekly for the 6-week program. The data (minutes of exercise) are normally distributed.
repeated measures ANOVA
Does test anxiety change during the first year of college? The sample contains 15 people, and anxiety is measured at four points in time: entry, end of first semester, end of second semester, and end of summer semester. The data (anxiety level) are normally distributed.
repeated measures ANOVA
Which of the following is not an assumption of ANCOVA?
the covariate should be a nominal number
Nonparametric tests such as the Kruskal-Wallis and the Mann-Whitney U-test should be used when
the data do not meet the distribution requirements for a parametric test
The Kruskal-Wallis test would be better than a one-way ANOVA when
the dependent variable is not normally distributed
The carryover effect best describes the situation in which
the experiences of an earlier trial affect the results of a later trial
The Kruskal-Wallis H-test can be used when
the measurement scale is ordinal
the position effect occurs under which of the following circumstances?
the order used to test the interventions affects the outcome
Statistical significance of an ANCOVA test is obtained by comparing
the p value to the a level
Statistical significance of an ANOVA test is obtained by comparing
the p-value to the a-level
Student's independent samples t test is best used when
the total sample size is at least 30. the grouping variable is dichotomous
The Mann-Whitney U-test is best used when
the total sample size is at least 8 and the grouping variable is dichotomous.
The Wilcoxon matched-pairs test is best used when
there are two matched groups to compare
The Kruskal-Wallis test is used to determine whether the distributions of which of the following are different from each other?
three or more independent measures
The means of which of the following are determined to be different by the repeated-measure ANOVA test?
three or more repeated measures
A study is conducted to see whether physicians' attitudes toward child abuse victims, adult victims of sexual assault, and adult victims of domestic violence are related to each other. Data are collected by a single survey conducted during a medical conference. These data include
three related measures taken at the same time
A study is conducted to examine the effect of three different anxiety-reduction techniques for dental patients. Each patient experiences a different technique in three different preventive (e.g., tooth cleaning) visits, which are spaced 6 months apart. These data include
three repeated measures over time from the same participant
The Mann-Whitney U-test is used to determine differences in the distribution of a variable in
two groups only
The independent samples t test is used to determine differences in the means of
two groups only
The situation in which an independent samples t test would be used instead of an ANOVA is
when there are only two categories in the grouping variable
ANCOVA uses residuals to determine
whether groups differ after the effect of some variable has been removed.
The one-way ANOVA test tells you
whether the mean of one or more groups is different from the others
The one-way ANOVA determines whether the means of the groups are different by comparing the
within-group variance to the between-group variance
Which test would be most appropriate to answer the following research question: Do patients with a history of cocaine use have more gumline cavities than other patients? There were 15 people in the sample (7 with a history of cocaine use and 8 without), and the number of gumline cavities was not normally distributed.
B - Mann Whitney U test
Which test would be most appropriate to answer the following research question: Is there a difference in the number of outpatient medical visits a year between military dependents and civilian dependents? There were 37 people in the sample, and the number of visits was left-skewed.
B - Mann Whitney U test
Which test would be most appropriate to answer the following research question: Is there any relationship between having children (having none compared with having one or more) and pay measured as an hourly wage? There were 1,021 people in the sample, and wages were left-skewed.
B - Mann Whitney U test
When analyzing the mean or median differences of paired data, which of the following are considered most important?
Both magnitude of the difference and statistical significance of the difference are equally important
Which test could be used to determine the difference in the average number of times in a month people exercise before and after a 3-hour exercise orientation program? There were 50 people in the sample, and the number of times people exercised was not normally distributed.
D - Wilcoxon matched pairs test
Consider the following question: Do people who eat after 8 PM sleep fewer hours than people who do not eat after 8 PM? Which variable is the grouping variable?
Eating before or after 8 pm
All of the following are outcome measures for MANOVA except
F
Consider the following question: Do women make more visits to their primary care physician in a year than men? Which variable is the grouping variable?
Gender
Consider the following question: Do children who are immunized against chick-enpox miss fewer days of school than children who are not immunized? Which of the following variables should be dichotomous to perform a Mann-Whitney U-test?
Immunization status
Consider the following question: Do children who are immunized against chickenpox miss fewer days of school than children who are not immunized? Which is the grouping variable?
Immunization status
Determine the relationship between preschoolers' scores on a fluency assessment and having older siblings (yes/no). The sample contains 22 preschoolers, and the data (fluency) are normally distributed.
Independent t test
Do the ounces of alcohol consumed in a week by undergraduate and graduate students differ? The sample contains 130 students, and the data (ounces of alcohol) are normally distributed.
Independent t test
Is there a difference in length of stay between two types of surgery to repair hernias in young children? The sample contains 25 children, and the data (length of stay) are normally distributed.
Independent t test
A group of researchers is interested in determining whether a relationship exists between geographic area (i.e., rural, suburban, and urban) and SAT math scores. The data include 2,100 scores, which are normally distributed.
Kruskal-Wallis H-test
Among entering kindergarten students, does a relationship exist between the number of letters of the alphabet recognized and the type of dwelling in which the child lived (i.e., house, apartment, and mobile home)? The sample contains 48 children, and the data (letters) are not normally distributed.
Kruskal-Wallis H-test
Determine whether a relationship exists between race (i.e., White, Black, Asian/Pacific Islander, other) and satisfaction with the economy (on a scale of 1 to 10, where 1 = extremely unhappy and 10 = ecstatic). Satisfaction is not normally distributed, and the sample contains 47 people.
Kruskal-Wallis H-test
Does type of news media affect the level of stress a story causes? These data on the level of stress are rated 1 to 5, with 5 being the highest reported by people who see a war-related story on television or read about it in the newspaper. The television group contains 21 people, the newspaper group contains 15 people, and the data (stress rating) are not normally distributed.
Mann Whitney U test
What is the relationship between the number of years a person is married and whether he or she dies by suicide or homicide? The data are from a study of premature mortality. The sample contains 121 people, and the data (marital duration) are not normally distributed.
Mann Whitney U test
Do significant differences exist between husbands and wives regarding holiday depression? There is an ordinal measure of depression, which is not normally distributed. The sample contains 47 couples.
Mann-Whitney U-test
If data are normally distributed in only one group, then which of the following tests can be used?
Mann-Whitney U-test
Consider the following question: Do people who exercise at least three times a week have lower systolic blood pressure than people who exercise less than three times a week? Which of the following variables should be normally distributed to perform a Mann-Whitney U-test?
Neither, because a normal distribution is not an assumption
Consider the following question: Among people with chronic back pain, do those who have their back pain treated by a chiropractor miss fewer days of work than those who are treated by a primary care physician? Is it possible to use an independent t test if the variable "number of days missed" is recoded into three-category variables (none, less than 3, more than or equal to 3)?
No
Consider the following question: Do people with chronic back pain who are treated by a chiropractor miss fewer days of work than people who are treated by a primary care physician? Can a Mann-Whitney U-test be used if the variable "number of days missed" is recoded into two-category variables (none, 1 or more)?
No
Does marijuana smoking increase the appetite of cancer patients? Compare three smoking groups (i.e., never, less than once a week, weekly or more) on the number of calories consumed in a week. Each group contains 14 people, and the data (calorie consumption) are normally distributed.
One way ANOVA
How much money was paid for a prescription of azithromax (Zithromax) by each type of insurance (i.e., Medicare, Medicaid, Blue Cross, and Cigna)? The sample contains 2,230 people, and the data (amount paid) are normally distributed.
One-way ANOVA
In a study of 72 women, a researcher wants to know whether cholesterol level is related to the women's highest attained degree (no degree, high school diploma, associate's degree, and bachelor's degree). The data (cholesterol levels) are normally distributed.
One-way ANOVA
A weight-loss program enrolled 45 heterosexual couples. Did the husbands lose more weight than their wives? The data (weight loss) are normally distributed.
Paired t test
Consider the following question: Do people who exercise three times a week or more have lower systolic blood pressure than people who exercise less than three times a week? Which variable should be normally distributed?
Systolic BP
If the variances of the two groups being compared are significantly different, which independent samples t test should be used?
The independent samples t test for separate variances
