Deck 11: Understanding Statistics in Research

Question 1

A researcher reports that results of a study were not statistically significant. How is this to be interpreted?

A) Intervention was not strong enough to make a difference.
B) Researcher does not have enough evidence to reject the null hypothesis.
C) Researcher's logic or conceptualization in setting up the study was faulty.
D) Topic is of no further interest to nurse researchers or clinicians.

Answer 1

Researcher does not have enough evidence to reject the null hypothesis.

Question 2

There is a greater risk of making which error with a directional hypothesis?

A) Concluding that there is a difference between groups when there really is no difference
B) Concluding that there is no difference between groups when there is an inverse relationship
C) Concluding that there is no difference between groups when there really is a difference
D) Rejecting the null hypothesis when the measurement error is moderate

Answer 2

Concluding that there is a difference between groups when there really is no difference

Question 3

Level of significance, sample size, power, and effect size are the four components of:

A) decision theory.
B) exploratory analysis.
C) inference.
D) power analysis.

Answer 3

power analysis.

Question 4

Under what condition would the mean, median, and mode be equal?

A) Equal range and standard deviation
B) Multimodal distribution of scores
C) Normal distribution of scores
D) Small variance

Question 5

What proportion of the standardized scores of a sample lies between the Z-scores of -1.96 and +1.96?

A)34.0%
B)47.7%
C)68.3%
D)95.5%

Question 6

A Type I error could occur for which of the following reasons?

A) Large difference between groups
B) Large sample size
C) Lenient level of significance
D) Normal distribution

Question 7

Which of the following interpretations is acceptable as worded?

A) Findings suggest that cholesterol levels influence cardiac blood flow.
B) Results demonstrate that lithium has hazardous side effects in all humans.
C) The positive correlation between age and reaction time indicates that age is a causal factor in automobile accidents.
D) The study proved that cigarette smoking causes lung cancer.

Question 8

Which of the following is true about Type I errors?

A) Considered only when results are not statistically significant in a study
B) Extremely likely to happen when p is less than 0.001
C) More likely to happen when p is less than 0.01 rather than p is less than 0.05
D) Occur when the researcher says there is a significance, but findings are actually not statistically significant

Question 9

The mean is represented by which score in the following frequency distribution?

A) 12
B) 10
C) 9
D) 7

Question 10

The likelihood that a statistical value obtained through analysis of the data is likely to occur in any two samples selected from the same population is called:

A) degrees of freedom.
B) induction.
C) interval estimation.
D) probability.

Question 11

In the following frequency distribution of data, the score 12 is which measure of central tendency?

A) Frequency
B) Mean
C) Median
D) Mode

Question 12

The level of significance usually set in nursing studies is at either:

A).5 or .1.
B).03 or .003.
C).05 or .01.
D).005 or .001.

Question 13

Descriptive statistics should be reported in every study to:

A) determine validity.
B) indicate reliability.
C) provide a powerful analysis of data.
D) show the sample characteristics.

Question 14

A researcher notes that 3 of 30 subjects had extreme anxiety scores when compared with the other subjects. These three subjects would be treated as:

A) deviants.
B) outliers.
C) unexpected findings.
D) ungrouped participants.

Question 15

Which of the following questions relates to generalization?

A) Are the findings generally significant to people in the study?
B) Can these findings be applied to other groups or settings?
C) Does the degree of control in the study allow for statistical significance?
D) How many alternative explanations or rival hypotheses can be proposed?

Question 16

Results of an ANOVA analysis of three specialty nursing groups indicate there is a significant difference between groups on the practice of spiritual care. To determine where the difference occurs, the researcher would need to run which statistical analyses?

A) Confirmatory
B) Post hoc
C) Predictive
D) Relational

Question 17

Type I errors are more likely to occur when the level of significance is less than:

A)0.05.
B)0.01.
C)0.001.
D)0.0001.

Question 18

A statistically significant finding means that:

A) findings are clinically important and valuable.
B) interventions should be used in clinical practice.
C) obtained results are not likely to have been due to chance.
D) results will be the same if the study is repeated with another sample.

Question 19

Which of the following levels of significance would decrease the chance of a Type II error?

A)0.10
B)0.05
C)0.01
D)0.001

Question 20

Which of the following is true about the level of significance? The level of significance:

A) ensures that findings will be correct 95% of the time if an alpha value of less than 0.05 is used.
B) refers to a statistic calculated during computer analysis of data.
C) represents the probability of getting a calculated statistic as high as the one found in the study if the null hypothesis is really true.
D) represents the risk the researcher is willing to take in making a Type I error and is established before data are analyzed.

Question 21

The mean scores of two groups participating in a study are exactly the same for a particular variable. This suggests that the:

A) average score is the same, but distribution of scores for each group are not known.
B) distribution and range of scores will be similar.
C) groups are definitely heterogeneous in relation to this variable.
D) groups are very much alike in relation to the variable.

Question 22

If a nurse researcher found that older patients asked fewer questions before surgery than younger patients, the relationship would be described statistically as:

A) negative.
B) null.
C) positive.
D) random.

Question 23

Which of the following is true about the chi-square statistic?

A) Expected and observed frequencies or proportions are compared.
B) Interval level data are used for all variables.
C) Post hoc testing is used to identify areas of group differences.
D) Results are reported in terms of differences between group means.

Question 24

Which of the following measures would be helpful in interpreting the relationship of a particular score to the distribution?

A) Frequency
B) Mean
C) Standard deviation
D) Variance

Question 25

The information, "t = 9.28 (df = 18)" indicates:

A) that it is unlikely there is a significant difference in scores between groups.
B) that more than two groups of subjects participated in the study.
C) nothing about the statistical significance of the findings.
D) that scores for analysis came from independent groups of subjects.

Question 26

Which test statistic is calculated in analysis of variance (ANOVA)?

A) r
B) F
C) t
D) X²

Question 27

What percent of scores will be within one standard deviation above or below the mean?

A) 34
B) 68
C) 95
D) 99

Question 28

Which of the following is true about the Pearson product moment correlation?

A) Determines relationships between a set of predictors and one outcome
B) Examines bidirectional relationships between two variables
C) Investigates relationships between an independent and dependent variable
D) Measures variables at the nominal level

Question 29

Which of the following correlation coefficients shows the strongest relationship?

A)0.10
B)0.30
C)0.90
D)0.92

Question 30

The mean of the following set of numbers (12, 4, 13, 20, 4, 10, 14) is:

A)4.
B)10.
C)11.
D)17.

Question 31

In estimating the parameters of a population of students categorized by year in school, which of the following estimators is the most nonbiased?

A) Mean
B) Median
C) Standard deviation
D) Variance

Question 32

What statistical test would you use to test the difference in heart rate response to exercise between a group of cardiac patients involved in a formal cardiac rehabilitation program and another group exercising at home?

A) Central tendency
B) Chi-square
C) Pearson product moment correlation
D) t-test

Question 33

The median is represented by which score in the following frequency distribution?

A) 12
B) 10
C) 9
D) 7

Question 34

Standard deviation is defined as:

A) a difference score based on the lowest and highest value in the set.
B) scores grouped so that the range in each set is standardized and equal.
C) scores that have been standardized to have a mean of zero.
D) the average difference between the mean and each of the scores in the set.

Question 35

Which test statistic is calculated for Pearson product moment correlation?

A) F
B) r
C) t
D) X²

Question 36

What statistical test would you use to simultaneously test the difference between temperatures of four groups of subjects?

A) ANOVA
B) Chi-square
C) t-test for dependent samples
D) t-test for independent samples

Question 37

Which of the following is an exploratory data analysis technique that is used to graphically illustrate the relationship of scores on one variable with scores on another variable?

A) Box-and-whiskers plot
B) Q-plot
C) Scatterplot
D) Stem-and-leaf display

Question 38

The median of the following set of numbers (12, 4, 13, 20, 4, 10, 14) is:

A)4.
B)11.
C)12.
D)17.

Question 39

Assuming a normal distribution, where would you find approximately two thirds of the scores if they ranged from 30 to 68, M = 45, and SD = 7 Between:

A) 30 and 68
B) 31 and 59
C) 37 and 61
D) 38 and 52

Question 40

Which of the following will be most affected by scores that are extremely high or extremely low?

A) Mean
B) Median
C) Mode
D) All of the above are affected equally.

Question 41

A recent research study investigating weight loss in the morbidly obese, found a statistically significant (p = 0.01) difference between subjects who followed an individually planned diet regimen with aerobic exercise and those in the treatment group, who also followed an individually planned diet regimen with aerobic exercise, but in addition, took a new medication. The medication, though extremely costly, created an additional 12 pound weight loss over the 3-month trial. What recommendations would be expected to come from this study?

A) Further research is suggested as the medication appears promising.
B) The findings are modest at best; the medication should not be recommended.
C) The medication can provide significant results for anyone needing to lose weight.
D) The expense is much too great to ever justify use of this medication.

Question 42

Which of the following are purposes of statistical analysis?

A) Prove the research hypothesis to be true.
B) Examine the numerical data gathered in a study. Provide insight into the meaning of the data.
C) Determine correct protocols for clinical research.
D) Prove the validity of a nursing theory.

Question 43

In reviewing a research study, which of the following statements would indicate clear problems with the findings?

A) "Descriptive statistics indicated confirmation of the generalizability of the findings."
B) "From the random sample of 1500 subjects from 16 colleges and universities, it was determined that nursing students tend to eat healthier while studying for an exam than other undergraduate students."
C) "The instrument selected has been used in many previous studies and has good reliability and validity."
D) "The sample consisted of 5000 clients with hypertension cared for in primary care settings from around the county."

Question 44

When preparing data for analysis, which of the following variables would not most likely be grouped for statistical analysis?

A) Ounces of water consumed by new mothers
B) Race and ethnicity of nursing faculty members
C) Results of fasting blood sugar testing
D) Weight of student athletes

Question 45

Unexpected results are best dealt with in which of the following ways?

A) Included in the final report
B) Incorporated into the ongoing study
C) Ignored because they are suspect findings
D) Interchanged with the dependent variable

Question 46

Research is reported in which the t-test is used to make multiple comparisons within the groups established for the study. Which of the following statements would someone reading the research correctly include in a critique of the study?

A) "The researcher did not appear to know how to make correct use of the t-test."
B) "The t-test is the correct statistic to use when making comparisons between groups."
C) "There is concern over a Type II error caused by the multiple use of t-tests."
D) "With no mention of the Bonferroni procedure, it is difficult to judge the levels of significance."

Question 47

In interpreting findings of a study, the researcher should:

A) avoid discussion of problems encountered while doing the study that might influence outcomes.
B) emphasize that statistically significant findings must be incorporated into practice.
C) relate findings back to the purpose and framework of the study.
D) speculate about what the findings might mean to nursing practice.

Question 48

Increasing the size of the sample can have an effect on the:

A) alpha level.
B) internal consistency.
C) measurement error.
D) Type II error.

Question 49

One key difference between research and evaluation is the ability of the researcher to:

A) control all extraneous variables.
B) generalize the results to a larger population.
C) predict the outcome based on probability factors.
D) remain objective during the research process.

Question 50

Nonsignificant findings are interpreted to mean the:

A) differences between the groups are of little importance clinically.
B) groups are not statistically different.
C) study did not detect any differences between groups.
D) study results approached significance, but were not mathematically supported.

Question 51

Which of the following is an example of a dependent group?

A) Chemotherapy recipients randomly assigned to receive either a new antiemetic drug or normal care
B) Nurses practicing in the hospital setting evaluated against those in community settings
C) Patients in cardiac rehabilitation measured for outcomes before and after completion of the program
D) Students involved in volunteer activities in a BSN program compared with those in an ADN program

Question 52

The researcher's own voice is heard most in which section of a study?

A) Conclusions
B) Findings
C) Literature review
D) Results

Question 53

Which of the following variables are not matched correctly with their probable grouping status (grouped or ungrouped) in a frequency distribution?

A) Age-grouped
B) Gender-grouped
C) Marital status-ungrouped
D) Time-grouped

Question 54

A researcher notes that although no mathematical significance was found, some premature infants who were exposed to soothing music for 6 hours daily exhibited lower heart rates and less crying. This finding would have which type of significance?

A) Clinical
B) General
C) Inferential
D) Statistical

Question 55

Which of the following study results are most common?

A) Mixed results
B) Nonsignificant results
C) Significant and predicted results
D) Unexpected results