NURSING RESEARCH CHAPTER 13

the point at the center of a data set

median

the number of modes found in a data distribution

modality

the most frequently occurring value in a data set

mode

inferential statistical test that describes the relationship of 3 or more variables

multiple regression

the use of statistical tests to provide information about one variable

univariate analysis

the use of statistics to describe the relationship between two variables

bivariate analysis

Match the following terms: 3 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

a

Match the following: 3 1. chi square 2. t test 3. ANOVA 4. pearsons r 5. multiple regression a) uses the f statistic b) tests for the significance of correlation between two variables c) has independent and correlated variations d) tests the significance of relationship among three or more variables e) tests for differences between groups using nonparametric data

a

When data have no outliers, researchers prefer to report the a. mean b. median c. mode d. magnitude

a

to describe the frequency of the single variable myocardial infarction in adults ages 30-49, which of the following could be used? SELECT ALL THAT APPLY a) descriptive statistics b) inferential statistics c) univariate analysis d) bivariate analysis

a,c

inferential statistical tests are used to: SELECT ALL THAT APPLY a) make assumptions about the population b) describe the sample with means and standard deviations c) test hypotheses by asking if there are differences between the groups d) select a sample e) determine whether results occurred by chance

a,c,e

probability of making a type I error

alpha level

a data set that does not have a mode

amodal

inferential statistical test used when the level of measurement is interval or ratio and more than two groups being compared

analysis of variance

Match the following terms: 1 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

b

Match the following: 4 1. chi square 2. t test 3. ANOVA 4. pearsons r 5. multiple regression a) uses the f statistic b) tests for the significance of correlation between two variables c) has independent and correlated variations d) tests the significance of relationship among three or more variables e) tests for differences between groups using nonparametric data

b

a researcher is studying the relationship of the amount of time ICU patients spend lying on their backs and urine output. Which test would the researcher use to analyze the data? a) chi square b) pearsons r c) phi coefficient d) multiple regression

b

when a researcher accepts the null hypothesis when it really should have been rejected, the researcher: SELECT ALL THAT APPLY a) committed a type 1 error b) committed a type II error c) obtained significant results d) obtained nonsignificant results

b,d

a data set with two modes

bimodal

Match the following terms: 4 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

c

Match the following: 2 1. chi square 2. t test 3. ANOVA 4. pearsons r 5. multiple regression a) uses the f statistic b) tests for the significance of correlation between two variables c) has independent and correlated variations d) tests the significance of relationship among three or more variables e) tests for differences between groups using nonparametric data

c

The most frequent data value in a set of data is the a. mean b. median c. mode d. average

c

a common statistic used to analyze nominal and ordinal data to find differences between groups

chi square

a percentage used to compare standard deviations when the units of measure are different or when the means of the distributions being compared are far apart

coefficient of variation

ranges established around means that estimate the probability of being correct

confidence intervals

a variation of the t test used when there is only one group or when groups are related

correlated t test

an estimate ranging from 0.00 to +1.00, that indicates the reliability of an instrument; statistic used to describe the relationship between two variables

correlation coeffiicients

Match the following terms: 6 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

d

Match the following: 5 1. chi square 2. t test 3. ANOVA 4. pearsons r 5. multiple regression a) uses the f statistic b) tests for the significance of correlation between two variables c) has independent and correlated variations d) tests the significance of relationship among three or more variables e) tests for differences between groups using nonparametric data

d

the most commonly used alpha level in nursing research is a) .001 b) .0001 c) .005 d) .05

d

a statistical concept used to refer to the number of sample values that are free to vary, n-1

degrees of freedom

collection and presentation of data that explain characteristics of variables found in the sample

descriptive statistics

the way two variables covary

direction

Match the following terms: 2 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

e

Match the following: 1 1. chi square 2. t test 3. ANOVA 4. pearsons r 5. multiple regression a) uses the f statistic b) tests for the significance of correlation between two variables c) has independent and correlated variations d) tests the significance of relationship among three or more variables e) tests for differences between groups using nonparametric data

e

Is the following ethical or unethical: including information about incidental findings especially when they involve side effects or risks

ethical

Is the following ethical or unethical: publishing articles about studies with nonsignificant findings

ethical

Match the following terms: 5 1. range 2. semiquartile range 3. percentile 4. standard deviation 5. z score 6. coefficient of variation a) rank b) difference between the maximum and minimum values c) measures of the average deviations of a value from the mean d) percentage comparing standard deviations when units of measure are different e) range in the middle 50% of data f) converted standard deviation to a standardized unit

f

All statistically significant findings have clinical significance. true or false

false

If data are highly uniform, a low peak will be observed in a graphic representation of the data TRUE OR FALSE

false

frequency distributions are an effective way to present inferential statistics TRUE OR FALSE

false

the total number of subjects in a sample is represented by the symbol n TRUE OR FALSE

false

the degree to which elements are diverse or not alike

heterogenous

elements that share many common characteristics

homogenous

a variation of the t test used when data values vary independently from one another

independent t test

analysis of data as the basis for prediction related to the phenomenon of interest

inferential statistics

measures providing information about differences among data within a set; measures of dispersion.

measures of variability

The peakedness or flatness of a data set is referred to as:

kurtosis

the strength of the relationship existing between two variables

magnitude

the mathematical average calculated by adding all the values and then dividing by the total number of values

mean

measures that provide information about the typical case found in the data

measures of central tendency

the use of statistics to describe the relationships among three or more variables

multivariate analysis

a distribution when the mean is less than the median and the mode; the longer the tail is pointing to the left

negatively skewed

inferential statistics involving nominal or ordinal level data to make inferences about the population

nonparametric

when results of the study could have occurred by chance; findings that support the null hypothesis

nonsignificant

data representation with a distinctive bell shaped curve, symmetric about the mean

normal distribution

inferential statistical tests involving interval- or ratio- level data to make inferences about the population

parametric

an inferential statistic used when two variables are measured at the interval or ratio level

pearsons r

descriptive statistics used to group data to make results more comprehensible; calculated by dividing the frequency of an event by the total number of events

percentage distributions

a measure of rank representing the percentage of cases that a given value exceeds

percentile

characteristics of a population that are inferred from characteristics of a sample

population parameters

calculated by using the formula (n+1)/2, where n is the number of data values in the set

position of the median

a distribution when the mean is greater than the median and the mode; the longer the tail is pointing to the right

positively skewed

likelihood or chance that an event will occur in a situation

probability

the difference between the maximum and minimum values in a data set

range

rule stating that for every sample 68% of the data will fall within one standard deviation of the mean; 95% will fall within two standard deviations; 99.7% will fall within 3 standard deviations

rule of 68-95-99.7

numerical data describing characteristics of the sample

sample statistics

a theoretical distribution representing an infinite number of samples that can be drawn from a population

sampling distribution

error resulting when elements in the sample do not adequately represent the population

sampling error

the range of the middle 50% of the data

semiquartile range

an asymmetrical distribution of data

skewed

a measure of variability used to determine the number of data values falling within a specific interval in a normal distribution

standard deviation

when critical values fall in the tails of normal distributions; when findings did not happen by chance alone

statistically significant

the branch of mathematics that collects, analyzes, interprets and presents numerical data in terms of samples and populations

statistics

the numerical outcomes and probabilities derived from calculations on raw data

statistics

inferential statistical test to determine whether a statistically significant difference between groups exists

t statistic

the degree to which a tail in a distribution is pulled to the left or the right

tailedness

Categories in grouped data must be mutually exclusive TRUE OR FALSE

true

If the tail of a distribution is skewed to the left, the data are negatively skewed TRUE OR FALSE

true

Nurses should determine that researchers are using the correct statistical tests to analyze data. True or False

true

Percentages are often used to describe characteristics of samples TRUE OR FALSE

true

Reading the table after the text is a helpful strategy that can improve comprehension of ideas. True or False

true

data contained in tables are an important source of evidence for practice TRUE OR FALSE

true

in a normal distribution, the mean, median, and mode are the same value TRUE OR FALSE

true

when the researcher rejects the null hypothesis when it should have been accepted

type 1 error

when the researcher inaccurately concludes that there is no relationship among the independent and dependent variables when an actual relationship does exist; when the researcher accepts the null hypothesis when it should have been rejected

type II error

Is the following ethical or unethical: selecting an alpha of .05 so that the research hypothesis is supported when it would not be if the alpha were set at .01

unethical

a data set with one mode, such as normal distribution

unimodal

standardized units used to compare data gathered using different measurement scales

z scores