CHAPTER 13

In a sample of 250 patients with cancer, the scores on a scale that measured resilience ranged from 10 to 70. There were two peaks in the distribution, at the scores of 25 and 55. What would this distribution be called? A) Unimodal B) Bimodal C) Asymmetric D) Normal

B

Which of the following is a statistic associated with logistic regression? A) OR B) R2 C) t D) F

A

Which statement about standard errors of the mean (SEM) and sampling distributions is true? A) One component in the formula for estimating SEMs is the standard deviation for the sample. B) Researchers construct sampling distributions from their study data. C) A sampling distribution of the mean is positively skewed. D) The larger the SEM, the more accurate are sample means as estimation of population means

A

A researcher wants to estimate how many people would need to receive a fall prevention intervention to prevent one fall. What index would the researcher compute? A) Number needed to treat B) Odds ratio C) Absolute risk reduction D) Absolute risk

A

An instrument's ability to correctly identify a case is its: A) sensitivity. B) specificity. C) content validity. D) ROC curve.

A

Analysis of covariance (ANCOVA) removes the effect of which type of variable before testing whether mean group differences on the outcome are statistically significant? A) Confounding variable B) Mediating variable C) Independent variable D) Dependent variable

A

If a power analysis indicated that for a given sample size, the power was .50, which would be true? A) The risk of a Type II error would be 50%. B) The results would be statistically significant 50% of the time. C) The 95% CI would have a range of 50 points. D) The risk of a Type I error would be 50%.

A

In a sample of 300 adults, a researcher tests the hypothesis that men and women differ in the amount of time (number of hours) they spend exercising weekly. Which of the following statistical tests would the researcher likely use? A) An independent groups t-test B) A chi-squared test C) A dependent groups t-test D) A paired t-test

A

In a study on patient compliance, a nurse researcher administered a questionnaire and asked about the participants' marital status. What is the level of measurement of the variable marital status? A) Nominal B) Ordinal C) Interval D) Ratio

A

In an analysis of variance (ANOVA), what is the test statistic? A) F ratio B) t C) d D) r

A

In analyzing scores on an anxiety scale, a nurse researcher found the scores were distributed from 62 to 98 in the research sample. What is the range? A) 36 B) 62 C) 98 D) 160

A

The use of inferential statistics permits researchers to: A) draw conclusions about a population based on data from a sample. B) describe data obtained from a population. C) interpret parameters. D) interpret the laws of probability.

A

There are four levels of measurement. Variables measured at which two levels are often called continuous variables? A) Interval and ratio B) Nominal and ordinal C) Ordinal and interval D) Ordinal and ratio

A

What is the technical name for a distribution that is sometimes referred to as a bell-shaped curve? A) Normal B) Multimodal C) Bimodal D) Skewed

A

Which of the following is a characteristic of a normal distribution? A) 95% of the values are within two standard deviations above and below the mean. B) The range of scores is from 20 to 80. C) The values are positively skewed. D) The mean is 50.0.

A

A 95% CI in parameter estimation corresponds to which alpha value in a hypothesis testing framework? A) An alpha of .95 B) An alpha of .05 C) An alpha of .99 D) An alpha of .01

B

A 95% confidence interval is associated with how many standard deviation (SD) units? A) 0.95 B) 1.96 C) 2.58 D) Depends on the sample size

B

A group of 500 elders completed a test of cognitive functioning. The mean score was 85, the standard deviation was 5, and scores were normally distributed. Approximately what percentage of the 500 scores fell between 80 and 90? A) 34% B) 68% C) 95% D) Impossible to determine

B

A nurse researcher reported that, for scores on a 12-item scale of empathy,x = 43. What does the symbol x represent? A) An effect size B) A mean C) Total sample size D) An individual score

B

A nurse researcher wants to describe the relationship between marital status (married vs. unmarried) and having a diagnosis of postpartum depression (yes vs. no). Which of the following would the researcher use to describe the data? A) Pearson's product-moment correlation coefficient B) A crosstabs table C) A correlation matrix D) Spearman's rho

B

A researcher compared the mean anxiety levels of patients who had been randomly assigned to a soothing music group, a massage group, or a control group. Which of the following statistical tests was likely used to test group differences in anxiety scores? A) t-Test B) ANOVA C) ANCOVA D) Chi-squared test

B

A researcher controls the risk of a Type I error by: A) selecting a sufficiently large sample. B) setting the level of significance. C) computing confidence intervals rather than using hypothesis testing. D) using the appropriate sampling distribution.

B

A researcher found a multiple correlation of .40 (R = .40) between candy intake, age, and income on the one hand and dental caries on the other. How much variability in dental caries, the dependent variable, can be accounted by the three predictor variables? A) 4% B) 16% C) 40% D) Cannot be determined Ans: B

B

A researcher wants to compare male and female oncology patients in terms of scores on a depression scale, controlling for age and severity of illness. The analysis would likely involve which test? A) Multiple regression B) ANCOVA C) Logistic regression D) Repeated measures ANOVA

B

Here are five score values: 5, 6, 9, 10, 10. Which measure of central tendency for this distribution would have a value of 9? A) The mode B) The median C) The mean D) The mode, median, and mean would be equal—all would be 9.

B

In a randomized controlled trial testing the effect of a smoking cessation program with 75 experimental group members and 75 control group members, which index would be a measure of the proportion of individuals in the control group who presumably would have stopped smoking had they received the intervention? A) Absolute risk B) Absolute risk reduction C) Odds ratio D) Number needed to treat

B

In a study on patients' fear of falling, a nurse researcher administered a questionnaire; one question asked about the participants' educational attainment (1 = high school, 2 = some college, 3 = college degree, 4 = graduate degree). In this example, what is the level of measurement of the variable educational attainment? A) Nominal B) Ordinal C) Interval D) Ratio

B

In reporting the results of a statistical test in a research article, which would not be reported? A) The computed value of the test statistic B) The theoretical value of the test statistic C) Degrees of freedom D) The probability (p) value

B

A researcher tested the hypothesis that a person's decision to have a colonoscopy was related to his or her perceived risk for colorectal cancer. With α = .05, the hypothesis was not supported. What might be a cause of this result? A) There were too many degrees of freedom. B) The alpha level was too conservative. C) The test had inadequate power. D) A researcher did not use an appropriate conceptual framework.

C

A researcher wanted to predict whether nursing home residents would or would not experience a fall within 6 months of admission based on four predictors (e.g., age, vision acuity, cognitive functioning, and having had a prior fall). The analysis would involve which of the following? A) Multiple regression B) ANCOVA C) Logistic regression D) MANOVA

C

Confidence intervals (CIs) address a question relating to the appraisal of evidence. Which of the following questions do CIs address? A) What is the quality of the evidence? B) What is the magnitude of effects? C) How precise is the estimate? D) What is the cost of applying the evidence?

C

In a sample of patients with peripheral neuropathy, a researcher found that the correlation between pain scores and age was .02. What does this mean? A) The older the patient, the much greater the pain score. B) Older patients had pain scores 2% higher than younger patients. C) Older patients had pain scores similar to younger patients. D) The relationship between pain scores and age was perfect.

C

When a statistical test has been performed, the computed p value is compared to the: A) theoretical distribution for the test statistic. B) values for the 95% CI. C) specified value of alpha. D) specified value of the power criterion.

C

Which measure exemplifies ratio-level measurement? A)Scores on a depression scale B) Apgar scores C) Urine output in milliliters per hour D) Employment status

C

Which measure of central tendency is the most stable? A) Mode B) Median C) Mean D) The mode, the median, and the mean are equally stable.

C

Which measurement property of a multi-item composite scale is estimated with coefficient alpha? A) Stability/reproducibility B) Interrater reliability C) Internal consistency D) Construct validity

C

Which of the following could not be a point estimate of a population parameter? A) .05% B) 520 C) 18.0 to 22.0 D) .95

C

Which of the following is an effect size index? A) t B) F C) d D) 2

C

Which of the following would be an example of a positively skewed attribute in general populations? A) Age at diagnosis of dementia B) Typical number of hours of sleep C) Number of years of education D) Age at retirement

C

A nurse researcher develops a scale to measure preparedness for caregiving among family members of palliative care patients. A panel of experts is recruited to assess the relevance of the items, and the results indicated a CVI of .91. What type of validity is being assessed? A) Content validity B) Internal validity C) Criterion validity D) Construct validity

A

A researcher is doing a test-retest assessment of a 10-item scale to measure fear of hospitals. What would be the preferred reliability statistic for this situation? A) The intraclass correlation coefficient B) Pearson's r C) Coefficient alpha D) Cohen's kappa

A

A researcher tested the hypothesis that patients in the ICU who were administered a silicone border foam dressing would be less likely than those without the dressing to experience incontinence-associated dermatitis. Which statistical test would the researcher likely use? A) A chi-squared test B) A paired t-test C) ANOVA D) An independent groups t-test

A

In terms of measurement levels for variables in a multiple regression analysis, which of the following is true? A) Nominal-level variables cannot be used as predictors in multiple regression analysis. B) Infant birth weight is measured at an acceptable level for use as either a predictor or a dependent variable in multiple regression. C) Smoking status (smoker vs. nonsmoker) is measured at an acceptable level for use as either a predictor or a dependent variable in multiple regression. D) The dependent variable in multiple regression can be measured at any measurement level.

B

What is the least conservative alpha that is considered acceptable? A) .10 B) .05 C) .01 D) .001

B

What is the most frequently occurring score in a distribution called? A) Average B) Mode C) Median D) Mean

B

Which of the following is a parameter? A) The average birth weight of a sample of 2,000 infants B) The average age of an accessible population of 50,000 nursing home residents in New York City C) The percentage of male and female in a sample of 5,000 patients D) The grade point average of nursing students responding to an Internet survey

B

Which of the following is the standard deviation of a sampling distribution of means? A) Sampling error B) Standard error of the mean C) Mean difference D) Square of the standard deviation

B

A researcher compared an experimental and control group on scores on a quality-of-life scale. The value of the calculated t statistic was -2.50 and the theoretical t value (for df = 60 and α = .05) is 2.00. The researcher would: A) conclude that a Type II error had been made. B) accept the null hypothesis. C) reject the null hypothesis. D) use a different level of significance.

C

A nurse researcher administered a 30-item scale that measured the severity of caregiver burden. What is the level of measurement of the scores on the scale? A) Nominal B) Ordinal C) Interval D) Ratio

C

A nurse researcher developed a new scale to measure stress in adolescents and calculated a Pearson's r between scale scores and a gold standard, wake-up salivary free cortisol levels. What type of validity is being assessed? A) Content validity B) Internal validity C) Criterion validity D) Construct validity

C

A nurse researcher wants to describe the relationship between patients' age and their scores on a 20-item social support scale. Which of the following would the researcher use in this descriptive analysis? A) A crosstabulation B) Spearman's rho C) Pearson's r D) A correlation matrix

C

A researcher reported the age of onset of Alzheimer's disease in a sample of residents in a memory care facility. What index of central tendency is likely to best communicate the information? A) The average B) The mode C) The median D) The mean

C

Which statement about errors in statistical decision making is true? A) A Type I error occurs when a researcher concludes that there is no relationship between variables when there is one. B) A Type II error occurs when a researcher concludes that there is no relationship between variables when there is none. C) A Type II error occurs when a researcher concludes that there is no relationship between variables when there is one. D) A Type I error occurs when a researcher concludes that there is a relationship between variables when there is one.

C

Which statement about standard deviations (SDs) is true? A) In a normal distribution, there are roughly 2 SDs above and below the mean. B) In a normal distribution, 1 SD above the mean accounts for 68% of the cases. C) The SD represents the average amount of deviation of scores from the mean. D) An SD of 10 indicates a distribution that is more heterogeneous than one with an SD of 20.

C

Which statistical test result would not be considered statistically significant? A) r = .19, p = .05 B) 2 = 12.33, p < .001 C) t = 1.70, p = .09 D) F = 3.23, p < .05

C

Which of the following is not one of the steps involved in hypothesis testing? A) Selecting the appropriate statistic to be used B) Specifying a level of significance C) Computing a test statistic D) Calculating the theoretical distribution for the test statistic

D

Which of the following is the most likely distribution for the variable height in a population of adults? A) Bimodal B) Positively skewed C) Negatively skewed D) Normally distributed

D

A researcher administered a self-esteem scale to a sample of 500 12-year-old children. The bulk of scores were at the upper end of the distribution. How would the frequency distribution for the scores be described? A) Normal B) Bimodal C) Positively skewed D) Negatively skewed

D

A researcher tested the effects of prenatal yoga on the mean stress levels of 100 pregnant women at three points in time—at baseline and at two points of follow-up. Which statistical procedure did the researcher likely use? A) Paired t-test B) Chi-squared test C) Analysis of variance (ANOVA) D) Repeated measures ANOVA

D

A researcher tested the hypothesis that weight gain during pregnancy was associated with infant birth weight. Which statistical test would be appropriate? A) A paired t-test B) ANOVA C) Chi-squared test D) Pearson's r

D

Consider the following hypothesis: The amount of daily daylight is unrelated to levels of depression in older adults. What type of hypothesis is this? A) Research hypothesis B) Alternative hypothesis C) Parametric hypothesis D) Null hypothesis

D

For a distribution of scores on a quality of life scale, the standard deviation was computed to be 4.0. What is the value of the range? A) 2.0 B) 4.0 C) 16.0 D) Insufficient information to determine

D

For which level of significance is the probability of committing a Type I error lowest? A) .10 B) .05 C) .01 D) .001

D

The standard error of the mean (SEM) gets smaller as which occurs? A) The mean gets smaller B) The sample size gets smaller C) The mean gets larger D) The sample size gets larger

D

The tendency of sample values (statistics) to fluctuate from one sample to another reflects: A) a Type I error. B) measurement error. C) a sampling bias. D) a sampling error.

D

There are four levels of measurement. What is ordinal measurement? A) A level in which characteristics are classified into discrete, mutually exclusive categories B) A level with equal distances between ordered values and a true meaningful zero point C) A level in which an attribute is ordered on a scale with equal distances between points on the scale but with no rational zero D) A level in which an attribute is rank ordered on a scale with unequal distances between points on the scale.

D

What is the range of the multiple correlation coefficient (R)? A) −0.10 to 0.00 B) −1.00 to +1.00 C) 0.00 to −1.00 D) 0.00 to +1.00

D

When a researcher reports that a result is statistically significant, what does this mean? A) The result is clinically meaningful. B) The result does not contain a Type I or Type II error. C) The result was consistent with the null hypothesis. D) The obtained result likely was not the result of chance.

D

Which is an index of variability that takes into account all score values? A) The range B) The median C) The mean D) The standard deviation

D