# In a one tailed test of significance,  The researcher is interested in extreme scores in only one tail of the distribution The hypothesis is nondirectional The possibility of rejecting the hypothesis is lower The 5% of statistical values that are considered statistically significant according to decision theory must be distributed between the two extremes of the curve

DNP-816: Analysis & Applic of Health Data for ANP

STATISTICS QUIZ 2

1. In a sample of 50  pregnant women, only 5 women end up having their baby  more than 1 week after the due date, while 10 are delivered at least 1 week prior to the due date.  What is the probability in this sample that a woman will deliver within 1 week of the due date?

.7 or 70%

10% or .1

.2 or 20%

80% or .8

1. If you are conducting a study to examine  relationships or predict an event, your study is based on which of the following theories?

Probablility

Decision

Causality

Power

No answer text provided.

1. What is the median for the following set of cases?

6, 7,  9, 10, 10, 11, 12, 13, 15, 16

10.5

10.9

10

11.2

1. According to Polit and Beck (2017), what is the best way to handle Likert scales when conducting research?

Use the total score of the questionnaire used in order to consider it interval level of measurement.

Because intervals between responses have not been shown to be equal, using Likert scales is not recommended

Use parametric statistics as Likert scales are not dependable.

Likert scales are considered nominal data and should not be used for statistical analysis.

1. Why is the level of measurement of variables important in a statistical analysis?

It affects what you can do with the data

It determines the direction of the relationship

It affects the power of a study

It determines the power of a study

1. Which example is below would be the best way to measure the  variable- weight?

Weight in pounds

Weight in three groups: under 125 lbs, 126 to 175 lbs and 176 lbs +

Nnormal weight or overweight

BMI score below 17, between 19 and 24 , above 25

1. Why is it important to measure variables at the highest level of measurement that is congruent with the concept being measured?

Data from a higher level of measurement can be converted to lower- level measurement, but lower level measurement can not be converted to higher level data

Each statistical analysis requires specified levels of measurement

More mathematical operations are possible with variables measured at the interval and ratio levels of measurement

All answers are correct.

1. A grouped frequency distribution:

Results in loss of information

Is seldom used with continous data

Provides more information as the number of groups decreases

Should avoid group definitions used in previous studies

1. Scatterplots are often used to visualize the relationship between two variables. Which of the following is true about these plots?

In correlation analysis, the line of best fit may be included on the plot

They give little information about the strength of a relationship

They give little information about the directionality of a relationship

Scatterplots reveal relationships only when the researcher has specified them in advance.

1. Which of the following is not trueconcerning the use of descriptive statistics?

Provides a mechanism for drawing conclusions about a population using a sample

They are used in every research study, qualitative as well as quantitative

They are used to identify patterns in data

They are used to address objectives of some studies

1. Which of the following is true about the mean?

It is the mathematical average of a set of scores

It is a measure reflecting the way a set of scores is spread out

It is unaffected by outlier or extreme scores

It represents the most frequently occurring score in set of scores

1. According to the theoretical normal curve, what percent of the scores in a data set are within one standard deviation (above and below) the mean?

68%

50%

95%

99%

1. A researcher is conducting a study on the effectiveness of different methods of test review on test scores based on the NCLEX test plan.  Which of the variables is the independent variable?

Methods of test review

Test scores

NCLEX test plan

The researcher

1. What does it mean when calculating a confidence interval that the confidence interval includes the number 1?

It means that there is not a significant p value.

It means there is a statistically significant result

It means that the statistics were not calculated correctly

It means that the sample size is too small

1. What is the best way to determine  how well  the sample statistic represents the unknown population parameter?

Calculate a Confidence interval

Determine central tendency

Determine variability

Calculate probability

STATISTICS QUIZ 3

• In a study examining the relationship between a participant’s age and number of friends, a Pearson r = -.62 was computed.  Which of the following best describes this finding?

As age increases the number of friends decreases

As age increases, the number of friends increase

As age decreases, the number of friends decreases

As age increases, the number of friends stays the same.

• Many researchers become excited when they identify statistically significant relationships between variables and may interpret this to mean that the relationship is very important. However, when the percentage of variance explained is calculated, the picture becomes less rosy. Which of the following is true about the percentage of variance explained?

All of the answers are correct

It is calculated by squaring the r value

The obtained value will be lower than the r value unless there is a perfect correlation

A correlation of .40 would explain only 16% of variance, leaving 84% unexplained

• Which of the following is true about correlational analyses?

All of the data should come from a single population

Data must be measured at the ratio level for these analyses to be valid

The range of values should be truncated or shortened in order for these statistical procedures to work

Data from groups that are different in some way are preferred in these analyses

• Below is a correlation matrix for four variables (A, B, C, D). Which value in the matrix indicates the strongest relationship?

 A B C D A B .62 C -.59 .45 D -.65 .52 -.27

-.65

-.59

.52

.62

• A correlation of +0.80 has been found between impulsivity and number of offenses committed in a group of young men. How much variance in impulsivity can be explained by number of offenses committed in percentage terms?

64%

20%

36%

84%

• The most common purpose for a Pearson’s correlation is to examine:

Relationships between two variables

Relationships among groups

Differences between variables

Differences between two or more groups

• 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 for the analysis?

A crosstabs table

Pearson’s produce-moment correlation coefficient

A scatter plot

Spearman’s rho

• A nurse researcher wants to describe the relationship between clients’ age and their scores on a 20 item social support scale. Which of the following would the researcher use to present the results of the analysis graphically?

A scatter plot

A crosstabs table

A correlation matrix

A histogram

• Match the following statistical tests with the level of measurement  or other requirement required for each analysis.

Group of answer choices

Pearson r

[ Choose ] Nominal data Ordinal data Ordinal, very small group size Interval or ratio data

Spearman ‘s Rank Order (rho)

[ Choose ] Nominal data Ordinal data Ordinal, very small group size Interval or ratio data

Kendall’s Tau

[ Choose ] Nominal data Ordinal data Ordinal, very small group size Interval or ratio data

Chi Square

[ Choose ] Nominal data Ordinal data Ordinal, very small group size Interval or ratio data

• What is a major weakness of correlational studies?

They are vulnerable to self-selection bias

They tend to be expensive

They tend to be artificial.

They are complex

• What is a central feature of non-experimental research?

The researcher does not manipulate the independent variable

The researcher manipulates the dependent variable.

Data are collected through the observation of participants’ behaviors.

The strength lies in their ability to elucidate cause-and-effect relationships.

• In a one tailed test of significance,

The researcher is interested in extreme scores in only one tail of the distribution

The hypothesis is nondirectional

The possibility of rejecting the hypothesis is lower

The 5% of statistical values that are considered statistically significant according to decision theory must be distributed between the two extremes of the curve

• If the null hypothesis was rejected and there was only 1 chance out of 100 that the decision was wrong, what was the alpha level in the study?

.01

.05

.10

.001

• What is a Type I error?

When we reject the null hypothesis when it is true

Obtaining a non-significant result by sampling error alone

Obtaining a non-significant result when it should be significant

Accepting the null hypothesis when in it is false

• A Type I error occurs when:

The results indicate a statistically significant difference, when in reality, there is no significant difference

The results are not statistically significant

The wrong statistical procedures are used

The data were not measure at the interval level

STATISTICS QUIZ 4

• When the results of an experiment can  confidently be attributed to the effect of the independent variable, the experiment is said to have

Construct validity

External validity

Statistical conclusion validity

Internal validity

• What does inferential statistics permit researchers to do?

Describe information from an emprirical observation.

Intepret descriptive statistics

Draw conclusions about a population based on data from a sample

Reject the null hypothesis

• What type of statistics are used to infer that the results from a sample are reflective of the true population scores?

Regression

Correlated statistics

Descriptive

Inferential

• A researcher tests the hypothesis that men and women differ in the amount of time (number of hours) they spend exercising weekly. Which statistical test might the researcher use, assuming a reasonable normal distribution of values?

Mann-Whitney U test

A chi-squared test

A paired t test

Independent groups t test

• Of the examples below, which one is describing a  within group design?

A study is conducted to examine the difference in reading ability in 6 year old children compared with children who are 8 years old.

The researcher conducts a study to examine the difference in coping style between engineering students and biology students.

A study is conducted to see if there is a statistically significant difference in anger expression between cat owners and dog owners.

A group of participants are tested on their recall of a list of words. They are tested immediately, 10 minutes later, 2 hours later and 24 hours later to determine how their scores differ between the three tests

• Which statistical test would you choose for  the following hypothesis?  “There will be a difference in attitude towards good dietary practice in individuals whose hobby is athletics as compared to individuals whose hobby is model aircraft assembly”.

Pearson product moment correlation

Independent t test

Linear regression

Dependent t test

• The level of measurement for the dependent variable (DV) in an ANOVA should be:

Nominal

Categorical

Ordinal

Interval or higher

• When analyzing data to determine differences between groups, it is important that the researcher know if the data sets are independent or dependent on one another and make any needed adjustments in statistical calculations. An example of  independent groups is:

Comparison of pretest and post-test groups.

Comparison of mother and daughter groups in relation to premenstrual symptoms

Intervention and control group made of different subject who were randomly assigned to groups

Matched pairs of subjects used for the control and treatment groups

• Which tool is useful for understanding the precision of  results?

Confidence intervals

Significance levels

Effect size indexes

Type I error rates

• A researcher tested the hypothesis that a person’s perceived risk for colorectal cancer was related to his or her cancer screening behavior.  With alpha = .05, the hypothesis was not supported.  What might be a cause of this result?

A nonparametric test was inappropriately used

The test was underpowered

Too many degrees of freedom

The alpha level was too conservative

• Consider the following hypothesis: The amount of daylight is unrelated to levels of depression in older adults.  What type of hypothesis is this?

Nonsignificant hypothesis

Research hypothesis

Alternative hypothesis

Null

• You want to compare the average heart rate of infants, children, teens and adults.  You will need to do multiple two sample t tests for this research.  Why is the use of t tests inappropriate in this situation?

T tests should be used in this situation, knowing that the result may have false positives

Correlation is a more appropriate statistic in this situation

When there are multiple tests with multiple dependent variables, the Type I error increases

Regression is the appropriate statistic as it enables prediction

• If you decided to make the critical p-value or alpha for significance as 0.001 as opposed to the conventional 0.05, what would the consequences be?

There would be fewer instances when the null hypothesis would be rejected

You would be more likely to make a Type II error

All of the answers

You would be less likely to make a Type I error

• A researcher wants to compare the entrance test scores on XYZ admission test by nursing students at his/her program to national data available on this same admission test. What is the best statistical test to find out whether the program mean admission test score differs significantly from the average national admission test score?

ANOVA

One sample t test

ANCOVA

Chi square test

• Which of the following is the correct way to report the results of a dependent sample t test?

The high school GPA statistically predicted college mathematics performance, R squared = .12, F (1,148) = 20.18, p < .001

t = 9.42, p = .001

The t test was significantly different between group one and group two

On average, the sample glucose level after the new diet (M=132.7, SE = 0.43) was significantly lower than that before the new diet (M= 155.7, SE = 0.46), t (35) = 8.38, p = .001.