Biostat Exam 1

Calculate the effect size for the following output. The effect size is

(Sum of squares between groups)/(sum of squares total)

If scores on a test gave a mean of 30 and SD of 8 what is the z-score for 22?

-1

In an experimental study where there are three levels of a treatment (usual care, education, education + social support) and you want to determine if the means across the 3 treatments are statistically different, what statistical procedure is best?

1-way ANOVA

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Bar graph

A

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Proportion

A

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Do people who are sneakers jump higher than people who wear a dress shoes?

A

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Medians

A or B

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Mode

A or B

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Frequency

A or B (mostly A)

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Admission to ICU

A.

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Tumor classification

A. Grading, ordinal

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above A researcher explored the relationship of a school wide smoking cessation program via a scale (normally distributed) between youth in one school and youth in another school (not matched). a. A b. B c. C d. D e. E

A. Independent t-test

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above Do nurses have a more favorable attitude (scale score, normally distributed) towards AIDS patients than physicians? a. A b. B c. C d. D e. E

A. Independent t-test

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above The IV is infant birth weight (low versus normal), the DV is number of days absent from school in first grade. a. A b. B c. C d. D e. E

A. Independent t-test

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Adherence to treatment plan

A. Nominal

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Color of bruises

A. Nominal, color

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Do nurses have a more favorable attitude (scale score) towards AIDS patients than physicians?

A. Nurses vs physicians

In a sample the distribution is unimodal. Mean (SD)=195 (14) median =175 A. Positively skewed B. Negatively skewed C. Multimodal D. Normal E. Kurtotic

A. Right or positively skewed

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Smoking history

A. Smoker or no smoker

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Pressure ulcers

A. Stages 1-4 ordinal

Why are we interested in determining the level of measurement? a. The level of the dependent variable determines what stat test we can run b. The level of the independent variable determines what stat test we can run c. We need to know what the value labels stand for d. We need to know which variable is larger than the others

A. The level of the dependednt variable determines which stat test we can run

The age distribution of people diagnosed with heart failure is most likely to be A. negatively skewed B. normally distributed C. positively skewed D. multimodal

A. negatively skewed

A nurse is studying the job satisfaction among different levels of nurses. Her research is to see if there is a statistically significant difference in mean job satisfaction scores (continuous variable with normal distribution) for registered nurses, licensed practice nurses and unlicensed assistive providers

ANOVA

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Box plots

B

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Interquartile range

B

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Skewness

B

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Variance

B

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis The school nurse explored the impact of a schoolwide smoking cessation program by comparing the number of cigarettes students smoked one month before and one month after the program

B

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Number if platelets on CBC report

B

Which are paired data as in paired t test? A. Comparisons of minutes of downtime per night of ED & LND nurses B. Comparisons of psychological development of identical twins over three years C. Comparisons of steps walked per day by elderly using canes to those using walkers D. Nurses working part time live longer than nurses working full-time

B (A,C,D is independent not paired)

Match the proper type of descriptive statistic or type of graph to the correct type of variable A. Nominal/ordinal B. Interval/ratio Range

B.

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Can people jump higher with when they are wearing Sneakers than when they are wearing dress shoes?

B. Paired data with 2 time periods

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above Can people jump higher (normally distributed) when they are wearing sneakers than when they are wearing dress shoes? a. A b. B c. C d. D e. E

B. Paired t-test

What kind of measurement? A. Nominal/ordinal or B. Interval/ratio Length of rehab stay

B. Time

What measure of central tendency usually lies between the other two measures of central tendency regardless of the direction of the skewness of a distribution? A. mean B. median C. mode D. standard deviation

B. median

Which of the following is an example of a dichotomous variable? a. BMI b. belief in the tooth fairy c. military ranking d. marital status

Belief in the tooth fairy

In its basic form, the ANOVA contrasts

Between group variances to within group variances

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Is there a statistically significant difference in main job satisfaction scores for registered nurses, licensed practical nurses, and unlicensed assistive providers?

C. 3 categories with one variable

Skewness refers to the A. Shape of the top of the curve B. The width of a curve C. Extent to which data are not symmetrical about the center D. Presence of outliers

C. Extent to which data are not symmetrical about the center

Which is not a measure of effect size? A. Cohen's d B. Pearson r C. F-test D. Odds ratio E. ETA squared

C. F-test

Standard deviation is best described by the following statement A. It is used to detect outliers B. It is the average distance of each point from the mean C. It is the average distance of each point from the mean D. Both a and b above are correct

C. It is the average distance of each point from the mean

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above Is the average math score different from two unrelated groups, assuming the math scores is non-normal distributed? a. A b. B c. C d. D e. E

C. Mann Whitney U

What kind of statistics can we use to describe an ordinal variable? a. Means b. Standard deviations c. Proportions d. Inferential statistics

C. Proportions

What are descriptive statistics used for? A. Used to examine relationships between variables in a dataset B. Used to see how well sample data can be generalized to the population C. Used to provide numerical or graphical summaries of data D. All of the above

C. Used to provide numerical or graphical summaries of data

Which of the following in NOT a demographic variable? a. number of children b. gender c. weight d. ethnicity

C. Weight

Which of the following is a Ratio level of measurement? a. A patient's temperature in the morning b. A patient's medical record number c. A patient's weight in the morning d. A patient's room number

C. a patients weight in the morning

When is it appropriate to use independent t tests? A. To test the association between the means of two groups B. To test the difference between the means of three groups C. To test the differences in the medians of two groups D. To test the difference between the means of two groups E. To test if they change between a pre-and post test is significant

D.

You notice the variable 'pain rating' which has a range of 1-10 has a missing value (4% os subjects) and missing values are coded as 999 in your data set of 100 post-op patients. Which of the following is of concern to you? A. Too small a sample size to run any analysis B. Biased results C. Loss of power due to missing D. How the missing is coded and analyzed E. All of the above

D. A is incorrect because not much is missing

Effect sizes emphasizes the A. Percentage of average scores among small samples B. Statistical significance C. Magnitude of the relationships for small sample sizes D. Magnitude of the relationship regardless of sample size

D. Magnitude of the relationship regardless of sample size

Which measure of central tendency would be best if the data are moderately negatively skewed A. Mean B. SD C. Mode D. Median E. Variance

D. Median

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Is there a difference in a patient quality of life score (assume normal distribution) by marital status (Single, married, or divorced and widowed) and employment?

D. Two variables marital status and employment

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above Do undergraduate student scores on nursing research exam increase in the time between entry into the BSN program and graduation (n = 16; assume non normal distribution for scores)? a. A b. B c. C d. D e. E

D. Wilcoxson signed-rank test

What level of measurement would be used if a participant was asked to report their level of pain on a scale that ranged from "Worst pain I have ever had" to "No pain"? a. Ratio b. Interval c. Nominal d. Ordinal

D. ordinal

It is good practice to look at missing values in your data because if too many missing it may result in A. Too small a sample size to run any analysis B. Biased results C. Loss of power D. A&B only E. A,B,C

E

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Do you students in my gym class (n=21) who are designer sneakers jump higher than those who wear plain sneakers?

E (n=21)

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above The IV is time since first diagnosis of cancer (1 month versus 3 months versus 6 months), the DV is body weight. a. A b. B c. C d. D e. E

E. None of the above

You are reading a manuscript were a T test P value in a table is P = 0.009. The author concludes that there is no significant difference. They have A. Made a type one error B. Made the correct inference C. Use the wrong statistical test D. Not corrected for different variances E. Made a type 2 error

E. Type 2 error

The effect size estimate in an ANOVA is known a the

Eta-squared

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Do scores on a general statistical knowledge exam increase in the time between entry into the DNP program and graduation? I assume non-normal distribution for scores, n=16

F. Small sample size with paired data

Select the appropriate test A. T-test for independent groups B. T-test for dependent groups C. One way ANOVA D. Two way ANOVA E. Mann Whitney U F. Wilcoxon signed rank G. Kruskal Wallis Is there a difference in satisfaction with life (scale) between levels of anxiety (none, moderate, high) in a sample where normality cannot be assumed?

G

A medical researcher identifies 3 well-known pain killer drugs (drug A, drug B, drug C) and recruits a group of 30 individuals with a similar level of back pain and randomly assigns them to one of the three treatment groups for a 4 week period. At the end of the 4 weeks, the researcher asks the participants to rate their back pain. The researcher wishes to compare the levels of pain (ordinal) experienced by the different groups at the end of the drug treatment period. What statistical approach do you recommend?

Kruskal-Wallis

If you intended to do a 1-way ANOVA but could only collect data on 7 patients in each of the three treatment arms, what non-parametric alternative could you use?

Kruskal-Wallis

Three groups of students study a passage of text for 30 minutes. Those in group 1 study with background noise at a constant volume. Those in group 2 study with noise that changes volume periodically. Those in group 3 study with no sound at all. After studying, all students take 10 point multiple choice tests (interval but non-normally distributed) over the material. What test do you use to determine if students will learn most effectively with a constant background sound, as opposed to an unpredictable sound or no sound at all.

Kruskal-Wallis

nonparametric tests

Mann-Whitney U-test, Wilcoxon signed-rank test (for matched pairs), Soloman and Kruskal-Wallis H-test

All of the following are assumptions for ANOVA except

Normal distribution of the independent variable

A sample of 80 children with chronic ear infections were treated with 1 of 4 drugs. After 3 months of treatment, parent satisfaction was measured across the 4 groups. The calculated ANOVA F statistic =2.424. If the critical F value is 2.725, what would your decision be about the null hypothesis?

The calculates F value is less than the critical F value, therefore the null hypothesis must be accepted.

A nominal level of measurement is used when the values of a variable have which of the following properties? a. They can be placed in meaningful order, have meaningful intervals between each other, but there is no true zero b. They can be placed in meaningful order, have meaningful intervals between each other, and have a true zero c. They can be placed in meaningful order, but there is no information about the size of the interval between each value d. They represent independent categories

They represent independent categories

A person who scores one SD below the mean has a higher score than a. 16% of the cases b. 34.1% of the cases c. 13.6% of the cases d. 68.2% of the cases

a. 16% of the cases

You are interested in evaluating how compliance with the DASH diet affects the stage of high blood pressure. You follow criteria to assess blood pressure as normal, prehypertensive, stage I hypertension, stage II hypertension, hypertensive crisis. Compliance will be a count of how many days the diet was followed in the past week. a. What is the dependent variable? b. What is the level of measurement of the dependent variable?

a. DV = blood pressure b. ordinal (categories with ordering)

You are interested in evaluating how compliance with the DASH diet affects the stage of high blood pressure. You follow criteria to assess blood pressure as normal, prehypertensive, stage I hypertension, stage II hypertension, hypertensive crisis. Compliance will be a count of how many days the diet was followed in the past week. a. What is the independent variable? b. What is the level of measurement of the independent variable?

a. IV = compliance b. Interval/ratio

A z score of 0 corresponds to the a. Mean b. standard deviation c. interquartile range d. 75th percentile

a. Mean

What effect size would be used to measure correlation? a. Pearson's r b. Cohen's d c. R2 d. Eta2

a. Pearson's r

The null hypothesis states a. that no relationship or difference will be found b. that a relationship or difference is expected c. an expected direction of the relationship d. that the distribution is normal

a. that no relationship or difference will be found

A variable is considered to be normally distributed if a. the mean= median=mode b. a lot (20%) of observations fall outside 2 standard deviations of the mean c. there is a bimodal distribution d. the distribution is not symmetrical

a. the mean= median=mode

Which of the following is NOT a measure of dispersion? a. the median b. the range c. the standard deviation d. the variance

a. the median

in hypothesis testing, Alpha refers to: a. the probability of making a Type 1 error b. the probability of making a Type 2 error c. 1 minus the power of a statistical test d. cannot tell

a. the probability of making a Type 1 error

A 95% confidence interval means a. there is 5 chances in 100 of making an error b. there is 95 percent confidence in the result c. there is 95 chances in 100 of making an error d. there is .95 chances in 100 of making an error

a. there is 5 chances in 100 of making an error

Given a normal distribution of scores with a mean of 100 and a standard deviation of 10 what is the z score for a score of 130? a. -3 b. +3 c. +2 d. 0.3

b. +3

Which of the following is normally true in behavioral research? a. Making a Type 2 error is seen as more dangerous than making a Type 1 error. b. Making a Type 1 error is seen as more dangerous than making a Type 2 error. c. Making a Type 1 and Type 2 error are seen as equally dangerous. d. It is not possible to compare Type 1 and Type 2 errors.

b. Making a Type 1 error is seen as more dangerous than making a Type 2 error.

A nursing instructor hypothesized that there are differences in the mean physiology exam scores depending on whether the type of instruction used was Face-to-face or Completely on-line. What would be the most appropriate statistical analysis to use to test this hypothesis, if the assumptions of normality were NOT met? a. Pearson correlation coefficient b. Mann Whitney U c. t-test d. Cannot determine

b. Mann Whitney U

What is considered the most stable index of central tendency? a. Standard deviation b. Mean c. Mode d. Median

b. Mean

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above The IV is parental role within couples (mother vs father ), the DV is degree of bonding with infant. a. A b. B c. C d. D e. E

b. Paired t-test

What measurement is likely to be normally distributed out of the following? a. Age of retirement b. Scores on SAT c. Number of accidents per hour in a 24 hour per d. Proportion of people liking Coke over Pepsi

b. Scores on SAT

An experiment was conducted in the middle of the Summer to test the efficacy of various sun blocks in protecting participants' skin from the harmful effects of the sun. Two types of sunblock were used, and researchers monitored the participants skin for signs of sunburn, controlling for amount of sun exposure. In the scenario above what is the independent variable? a. Summertime b. Sun blocks c. the participants d. Signs of sunburn

b. sun blocks

Beta refers to a. the probability of making a Type 1 error b. the probability of making a Type 2 error c. the p value d. 1 plus the effect size

b. the probability of making a Type 2 error

Which of the following is true about missing values a. they are always assigned the value of '9' b. they can lead to misleading results because of bias c. you can ignore if more than 20% of your sample provided responses d. they make analysis easier because less data to deal with

b. they can lead to misleading results because of bias

If the mean score for stress is 70 and the standard error of the mean =0.69, what is the 95% confidence interval around the mean? a. 70 +/- .69 b. 70 +/- .34 c. 70 +/- 1.4 d. 70 +/- .83

c. 70 +/- 1.4

Which of the following would be considered a type II error? a. A researcher validates a statistically significant difference when the p value is less than the alpha value. b. A researcher validates a statistically significant difference when the p value is greater than the alpha value c. A researcher fails to reject a null hypothesis that is false. d. A researcher fails to reject a null hypothesis that is true.

c. A researcher fails to reject a null hypothesis that is false.

A researcher studying adults with Stage 3/4 lung cancer, compared the depression scores between women and men. Depression was assessed using a scale in which a higher score represented a higher level of depression. Among the men, the mean scale score was 45; among the women, the depression score was 38. After testing for assumptions, a t-test was done and the following findings were reported: t = 5.25, p < .03. Based on these results the researcher could conclude: a. Gender is a significant cause of depression among lung cancer patients. b. Male lung cancer patient's depression scores were significantly lower than women's. c. Female lung cancer patient's depression scores were significantly lower than men's. d. There is no significant difference in depression scores between men and women.

c. Female lung cancer patient's depression scores were significantly lower than men's.

Assuming the distribution of data is normally distributed, what is the mean and standard deviation if you know that 95% of female preschoolers weigh between 32 and 42 pounds? a. Mean=0, SD=2 b. Mean=37, SD=5 c. Mean=37, SD= 2.4 d. Mean=36.5, SD=3

c. Mean=37, SD= 2.4

Distribution of data is described by the following EXCEPT: a. Variability b. Shape c. Population d. Central tendency

c. Population

A researcher collects his sample of participants by randomly selecting every other patient that walks into a clinic on a given day. What type of sampling techniques is he using? a. Cluster sampling b. Stratified sampling c. Systematic random sampling d. Simple random sampling

c. Systematic random sampling

Under what condition is a sample population curve more likely to look like the population curve ? a. When the bell shape of the distribution is wide b. When the sample size is small c. When the sample size is greater than 30 d. When the distribution is leptokurtic

c. When the sample size is greater than 30

Which is not a measure of effect size? a. Cohen's d b. Pearson r c. t-test d. Odds ratio

c. t-test

Which of the following is most influenced by outliers? a. the median b. the mode c. the mean d. the frequency

c. the mean

If the p-value of a statistical test is found to be significant, it means that a. the study didn't have acceptable power b. the findings have important clinical application c. the null hypothesis should be rejected d. all of the above are true

c. the null hypothesis should be rejected

If the results of a study found t=2.92, p=.04 for a 2-tailed test, what would be the p value if it was 1-tailed? a. 0.08 b. 0.05 c. 0.01 d. 0.02

d. 0.02

Which of the following would be considered a type I error? a. A researcher validates a statistically significant difference when the p value is less than the alpha value b. A researcher accepts a null hypothesis that has a p value that is less than the alpha value. c. A researcher accepts a null hypothesis that has a p value that is greater than the alpha value d. A researcher validates a statistically significant difference when the p value is greater than the alpha value.

d. A researcher validates a statistically significant difference when the p value is greater than the alpha value.

The term for the standard deviation of a sampling distribution of means is a. Confidence interval b. Population value c. Standardized score d. Standard error of the mean

d. Standard error of the mean

If a researcher is examining how exposure to cigarette ads affects smoking behavior, the cigarette ads are what type of variable? a. qualitative b. quantitative c. dependent d. independent

d. independent

Effect sizes emphasize the a. percentage of average scores among small samples b. statistical significance c. magnitude of the relationships for small sample sizes d. magnitude of the relationship regardless of sample size

d. magnitude of the relationship regardless of sample size

A presenter asks her audience to visit her website and respond to an online survey. What type of sampling techniques is she using? a. Systematic random sampling b. Purposive sampling c. Simple random sampling d. none of the above

d. none of the above

An experiment was conducted in the middle of the Summer to test the efficacy of various sun blocks in protecting participants' skin from the harmful effects of the sun. Two types of sunblock were used, and researchers monitored the participants skin for signs of sunburn, controlling for amount of sun exposure. In the scenario above what is the dependent variable? a. Summertime b. Sun blocks c. the participants d. Signs of sunburn

d. signs of sunburn

Which of the following CANNOT be used to display the frequency data of a nominal or ordinal variable? a. Pie chart b. Bar graph c. table d.Histogram

d.Histogram

What are three good practices to think about when it comes to missing values?

determine how many ( if <5% might be OK), note how they are coded as might need to be careful doing analyses, inform the reader when reporting findings

Using the following, select the appropriate test for each of the following: a. independent t-test b. Paired t-test c. Mann whitney U d. Wilcoxson signed-rank test e. None of the above The IV is sex (men vs women) , the DV is compliance versus noncompliance with a medication regime. a. A b. B c. C d. D e. E

e. None of the above

Skewness refers to the

extent to which data are not symmetrical about the center.

If a statistical test is significant it means that

the null hypothesis was rejected

When working with a datafile one can refer to a codebook to understand what kinds of things?

what 'question/piece of information' the variable is referring to. How responses were coded and what the codes mean