Quantitative Research Exam 2: Quizzes

The degrees of freedom for chi-square associated with 2 ' 3 contingency table will be:

2

A study was done to test the difference in heart rate with four different exercises. A sample of 10 patients were tested, each using the four exericses in random order. The appropriate test for this study would be:

Friedman ANOVA

A study is designed to test if children of parents who smoke also smoke. In a sample of 1000 parent/child pairs, each was asked if they currently smoke. Data were recorded as yes/no. To analyze these data, we would need to use:

McNemar test

Correlation is:

an estimate of shared variance between two variables

What type of data are applied to a chi-square test?

categorical

An ANOVA is run to determine if there is a difference among 5 treatment groups for relief of should pain in a sample of 65 patients. The analysis results in F = 2.41. The critical value and significance of this result is:

critical F = 2.53; the test is not significant

Which of the following conditions does not warrant the use of nonparametric statistics?

data are at the interval level

The effect size for the independent samples one-way ANOVA analysis can be calculated by:

dividing the between-groups sum of squares by the total sum of squares

True or False: A study is planned to determine the effectiveness of a mobilization technique in treating back pain. Participants are randomly assigned to two groups, one getting mobilization and the other getting active exercise. The paired t-test is the appropriate statistic for this analysis.

false

Under which column should you look in the output of an unpaired t-test to determine if variances are equal across groups?

levene's test

The ANOVA is based on all of the following assumptions except:

participants are chosen through a random sampling procedure

A researcher wants to study the relationship between gender and heart rate. Which of the following correlation statistics should be used?

point biserial correlation

Compared to their parametric counterparts, nonparametric statistics:

tend to have slightly lower power

A study was designed to compare three groups on balance scores following three types of balance training. 33 patients are randomly assigned to the two groups in a pretest-posttest design. An ANOVA resulted in F(2,30) = 3.25, p = .07, n2 = .09. What is your reasonable conclusion?

the F value is not significant, but power may be low and differences may be present with a larger sample

A researcher designs a study to measure differences in anxiety (measured 1-10) in patients who do and do not receive an anxiety medication. The appropriate statistic for this analysis would be:

the Mann-Whitney U test

A correlation between two variables X and Y resulted in r = .14 (p = .001). Which statement is a valid conclusion?

the correlation of .14 did not occur by chance

A researcher has studied the relationship between function and strength in individuals with dementia in a nursing care facility, finding a correlation of .75. Which of the following statements is a reasonable interpretation of this coefficient?

the decline in function or strength could be due to the individual's memory deficit

A study is done to compare two teaching strategies, A and B, to determine which method students prefer based on questionnaire responses. Which of the following statements is an accurate statement of the null hypothesis for this study?

the difference between means for A and B will equal zero

A paired t-test is a ratio of:

the mean difference divided by the standard error of the mean difference

Chi-square is used to look at:

the proportion of individuals in different categories

A researcher uses chi-square to examine the association between gender and the presence of migraine headaches. The null hypothesis for this study would be:

the proportion of men or women with or without migraines will not be different from what would be expected by chance

A study was done to look at the association between the presence of plantar fasciitis (PF) and weight (rated underweight, normal, overweight based on BMI) in 100 athletes. This created a 2'3 contingency table, with results shown in the table above. Numbers in red are expected frequencies (Standardized Residual). The results showed that x2=19.17 (p < .001). Which of the following conclusions is not correct?

the proportion of overweight athletes with PF is higher than expected

Correlation coefficients can provide information on all of the following except:

the relationship between variables that have a quadratic relationship

Which of the following assumptions is not relevant for the unpaired t-test?

the sample being tested should come from a random sampling of cases

A researcher is interested in establishing the relationship between quality of life and age. He recruits a sample of 30 patients in a skilled nursing facility. He finds a correlation of -.25 (p = .31). Most likely, the correlation is low because:

the sample was probably homogenous on age and quality of life

A study is done to compare two drugs to improve blood pressure using a sample of 42 patients (21 in each group). The researcher hypothesized that drug 1 would be better than drug 2. The results of a t-test are as follows: t(40) = 1.684, p = .05. Using a = .05. the researcher concludes that there is a significant difference. What would be the effect if he had hypothesized that there would be a difference between the two drugs?

the test would no longer be significant

What is the purpose of a goodness-of-fit test?

to determine if there is a significant difference between a pattern of observed frequencies and the pattern that would be expected by chance

A study is designed to examine the effect of exercise (against no exercise) on knee pain, with measurements taken at 1 week, 3 weeks, and 6 weeks. Participants are randomly assigned to one of the exercise conditions. The appropriate design would be:

two-way analysis of variance with one repeated measure

A study was designed to look at the difference in pain across 4 groups, each receiving a different dose of the medication. The results of a Kruskal-Wallis test showed H = 8.4 (p = .02). Based on the results of a multiple comparison, shown above, which statement is not a correct conclusion?

using .14 mg is better than any other dosage

An unpaired t-test is used to compare two treatments on a sample of 100 patients, resulting in a mean difference of 98 and a 95% confidence interval of 80 to 115. Which of the following statements is a correct interpretation of this confidence interval?

we are 95% confident that the interval 80 to 115 contains the true population mean difference

A study compared two drugs for reducing blood glucose levels in a sample of 32 individuals with diabetes. The researcher hypothesized that there would be a difference between the drugs. The result showed a difference of 10.368 between the two drugs, shown above. Which of the following statements is not an accurate interpretation of these data?

we are 95% confident that the true mean difference is between 3.905 and 16.831

A researcher has established a correlation of -.29 (p = .002) between knee strength and weight in adults. Based on this outcome, the relationship between strength and weight is:

weak because the size of the coefficient is small