415 quiz 6
what provides information regarding how different the data are within a set?
measures of variability
measure of central tendency that splits the data in half
median
the point at the center of a data set
median
the point at the center of the data set
median
correlations between .30-.50
moderate
tests the significance of relationships among 3+ variables
multiple regression
what test is used when researchers want to study the relationship of many independent variables on one dependent variable @ an interval/ratio level
multiple regression
the use of statistical tests to provide information about one variable
univariate analysis
correlations from .10-.30
WEAK
what type of analysis calculated correlation coefficients?
bivariate
When Testing For Relationships Among Variables what considerations have to be made? (2)
how many variables (>2>) LOM
with one mode
unimodal
beta (probability of Type II error)
B
Fisher's F ratio
F
married couple
dependent group
which type of statistic explains characteristics of variables found in a sample and describes, summarizes and synthesizes collected data?
descriptive
test scores from different groups of diabetic patients
independent group
the peakedness or flatness of a distribution of data
kurtosis
Mean
m = 118.28
probability
p
inferential statistical tests involving interval/ratio level data to make inferences about the population
parametric
tests used to make inferences about the population
parametric
a theoretical distribution representing an infinite number of samples that can be drawn from a population
sampling distribution
the average
the mean
which type of analysis: includes information regarding frequency distributions, measures of central tendency, shape of distribution, and measures of variability. AKA dispersion.
univariate analysis
chi square
x2
percentage
%
What test is this an example of: r
Pearson correlation
a researcher is studying the relationship about the amount of time ICU patients spend supine & UO. What test would the researcher use to analyze the data?
Pearson's R
tests for a correlation between 2 variables
Pearson's r
standard deviation
SD
alpha; probability of type I error
a
What test is this an example of: Χ2= 2.52
Chi squared
a percentage used to compare SD when the unit of measure are different or when the means of the distribution are far apart
coefficient of variation
a percentage used to compare standard deviations when the units of measure are different or wen the means of the distributions being compared are far apart
coefficient of variation
percentage comparing standard deviations when units of measurement are different
coefficient of variation
what experiments normally have 2 or more groups?
classic experiments, and quasi-experiments
how is the median determined in grouped data?
cumulative frequencies
parameter estimations can be used to
determine inferences to the population
what is the purpose of inferential statistics?
determine whether the null hypothesis should be accepted or rejected
degrees of freedom
df
what is the formula for degree of freedom
df=N-1
the way 2 variables covary
direction
the way two variables covary
direction
the most important factor in determining which statistical test to use is:
groups or variables
how are the results of descriptive analysis presented?
in a table with scientific notations
what is the most frequently used grouping?
independent groups
what type of statistics is used to test this hypothesis: is there a relationship among the hours of sleep and scores on a memory exam?
inferential statistics
what are the most common types of graphs? (5)
line charts, bar graphs, pie charts, histograms, and scatter grams
the strehngth of the realtinship between 2 variables
magnitude
the strength of the relationship between two variables
magnitude
what are correlations evaluated in terms of? (3)
magnitude, direction and significance
inferential statistics tests are used to: make assumptions about the population describe the sample with means and standard deviations test hypothesis by asking if there are differences in between groups select a sample determine whether results occurred by chance
make assumptions about the population test hypothesis by asking if there are differences in between groups determine whether results occurred by chance
what measure of central tendency describes continuous and nominal data?
mode
what measure of central tendency has the highest frequency in a distribution table?
mode
an inferential statistical test used to describe the relationship of 3+ variables @ an interval/ratio level
multiple regression
an inferential statistics test used to describe the relationship between 3 or more variables
multiple regression
what test would you use: which factors best predict an anorexic adolsecents' success at maintain a weight WNL. The IVs= self esteem, social support, anxiety, and locus of control.
multiple regression
the use of statistics to describe the relationship between 3 or more variables
multivariate analysis
the use of statistics to describe the relationships among 3 or more variables at interval/ratio level
multivariate analysis
groups must be
mutually exclusive
well defined lower and upper limits
mutually exclusive
number in a subsample
n
what type of test is a t-test
parametric
likelihood or chance that an event will occur in a situation (under the same conditions)
probability
the percentage of times that heads is likely to occur by chance alone
probability
what are the 4 conditions of parametric testing?
probability sampling normal distribution of data LOM= I/R reduction of error
other factors (3) in determining which statistical test to use is:
probability sampling method normal distribution of data confounding of variables
Pearson product-moment correlation
r
Pearson Correlation
r = 0.39, p<0.01
computing the overlap/shared variance of pearson's r
r2 (can be used to determine other variables affecting)
difference between maximum and minimum values
range
frequency
f
True or false: If the researcher calculates the probability level of p>0.05 and rejects the null hypothesis, the researcher has made a Type I error.
false
true or false all statistically significant findings are clinically significant
false
true or false if data are highly uniform, a low peak will be observed in a graphic representation of the data.
false
true or false the total number of the subjects in the sample is represented by n
false
true or false: frequency distributions are an effective way to present inferential statistics
false
why is chi square used so often?
finding differences between groups on demographic variables
what is compared in chi square statistics?
frequencies observed in the study and the expected frequencies if the null was true
table made out of raw data that organizes the data to present the information clearly
frequency distribution table
what needs to be consistent in grouping?
group size
correlations above .50
strong
inferential statistics involving nominal or ordinal level data to make inferences about the population
nonparametric
positive z score indicates
the observation is above the mean
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 distribution
calculated by dividing the frequency of an event by the total number of events
percentage distributions
descriptive statistics used to group data to make results more comprehensible
percentage distributions
what type of distribution is often used to present descriptive statistics?
percentage distributions
has independent and dependent correlated variations
t test
what central measure of tendency is used to describe the average when there is an extreme value in the data
the median
which measure of central tendency is used when the center of a data set is desired?
the median
what is the easiest measure of central tendency to determine because it is the most frequently occurring value in the data?
the mode
which measure of central tendency is used to determine the most frequent case?
the mode
which measure of central tendency uses continuous or nominal data values?
the mode
what does the F statitic indicate and why?
the null hypothesis can be rejected bc there is a difference between group means
What are degrees of freedom based off of?
the number of elements in the sample
true or false the position of the median gives only the position, and not the actual value of the the median
true
true or false the strongest inferences can be made when the LOM is interval or ratio, a probability sample was used, the sample size is adequate and the data is normally distributed.
true
true or false probability is affected by the concept of sampling error
true
true or false the mode is not affected by extreme values in the data
true
when grouping data it is imperative that:
there is not overlapping of data
true or false the mean and SD should always be reported together
true
true or false when the alpha level is larger there is more room for error
true
true or false ANOVA allows researchers to compare variations among groups using 1 test thus decreasing the chance of making type I error
true
true or false categories in group data must be mutually exclusive
true
true or false chi square can be done without a computer
true
when the researcher rejects the null when it should have been accepted (RA)
type I errors
in nursing when a practice does not change even though it should.
type II error
when the researcher inaccurately concludes that there is no relationship among variables when a relationship actually exists (AR). accepting the null even though it should have been rejected)
type II error
a standard score
z
what is the z score of the mean on a SD graph?
0
for an alpha of .01 how many times would an error would occur
1 out of 100
what type of CIs are normally reported?
95% or 99%
What test is this an example of: df=6
Degree of freedom
Analysis of Variance (ANOVA); Degrees of freedom
F = 3.59, df = 2, p < 0.05
what is ANOVA used to calculate?
F statistic (based on f distribution using DOF)
A nurse is reading about a study that investigated whether self-concept is related to adherence to medication plan. Self-concept and adherence to medication plan were measured as "good," fair," and "poor." What statistical test should the nurse expect to see described? o Chi square o Kendall's Tau o Pearson's r o Wilcoxin matched pair
Kendall's Tau
when you are trying to determine the relationship between variables with 2 variables with ordinal level data what test would you use?
Kendall's tau
the 2ND most important factor in determining which statistical test to use is:
LOM
what are the uses for nonparametric tests (2)
LOM nominal or ordinal abnormal distribution
median
Mdn
total number in a sample
N
what are the degrees of freedom for pearson's r?
N-2
what alpha level is most commonly used in nursing
.05
what is the most commonly used alpha in nursing research?
.05
in a normal distribution with standard deviations, how is the area designated in which 47.5% of scores are higher than the mean and 47.5% of scores are lower than the mean
2 standard deviations above and below
for an alpha of .05 how many times would an error occur?
5 out of 100
what is the minimum sample size in each cell of the table for chi square?
5+
Uses the F statistic
ANOVA
analysis of variance
ANOVA
an inferential statistic test used for interval/ration LOM when more than 2 groups are being compared
ANOVA (analysis of variance)
the probability of making type I error; typically designated as a .01 or .05 at the end of a tail in a distribution
Alpha
What test is this an example of: F=3.59
Analysis of variance
in order to avoid ______ decision making, researchers must state their selected probability of making a type I error in the initial research proposal
bias
a data set with two modes
bimodal
the use of statistical tests to describe the relationship between two variables
bivaraiate analysis
the use of statistics to describe the relationship between 2 variables
bivariate analysis
which type of analysis: can be expressed in contingency tables or with other statistical tests
bivariate analysis
What test is this an example of: p< 0.001
Probability level
multiple correlation
R
multiple correlation squared
R2
Standard Deviation
SD = 62.5
computation of the coefficient of variation
SD/M (percentage)
What test is this an example of: n=213
Sample size
Range of the middle 50% of data
Semiquartile range
What test is this an example of: t
T-test statistic
Chi square
X2 = 2.52, df = 1, p<.05
what is the goal of hypothesis testing?
accept true claims and reject false ones
designated as .05 or .01 at the end of of a tail in a distribution
alpha level
the probability of making a type I error
alpha level
a data set without a mode
amodal
without a mode
amodal
a inferential statistical test used when the LOM is interval or ratio and more than 2 groups are being compared.
analysis of variance (ANOVA)
when should alphas be chosen & why ?
at the beginning to avoid bias
Tests for differences between groups using non parametric data
chi square
a common statistics used to analyze nominal or ordinal data to find differences between groups
chi square
the common statistic used to analyze nominal and ordinal data to find differences between groups
chi square
what test would you use & why: studying the affects of aromatherapy on BP with a random assignment of 200 subjects divided into 2 groups. There are 54 women and 46 men in the 1st groups and 46 women and 54 men in the second group.
chi square, determine likeness of groups based on extraneous variables of gender (we can determine if changes are due to gender or as a result of the intervention)
what tests are used for answering questions about statistically significant differences between groups?
chi square, t-tests and ANOVA
when the researcher accepts the null even though it should have been rejected the researcher: committed type I error committed type II error obtained significant results obtained non significant results
committed type II error obtained non significant results
Percentages that estimate the probability of inferences in a study being correct are reported as
confidence intervals
how are parameter estimations reported
confidence intervals
range established around means that estimate the probability of being correct
confidence intervals
ranges established around means that estimate the probability of being correct
confidence intervals
how to we compare frequencies with Chi Square?
contingency tables
a variation of the t test used when there is only one group or when the groups are related (paired t test)
correlated t test
a variation of the t test where there is only one group, or two groups that are related
correlated t test (paired t test)
what type of test would you use: difference between subjects morning and evening BP readings
correlated t test (paired t)
an estimate ranging from 0- +1 that indicated the reliability of an instrument (used to describe the relationship between 2 variables)
correlation coefficient
an estimate ranging from 0-+1 that indicated the relability of an instrument a statisitic usd to describe the relationship among 2 variables
correlation coefficient
an estimate, ranging from 0 to +1, that indicates the reliability of an instrument; that is used to describe the relationship between 2 variables
correlation coefficient
an alpha level of .01 ______ type I errors, and ______ type 2 errors
decrease; increase
a statistical concept used to refer to the number of sample values that are free to vary n-1
degrees of freedom
a statistical concept used to refer to the number of sample values that are free to vary; n-1
degrees of freedom
measuring BP before and after exercise
dependent group
to describe the frequency of a single variable MI in adults age 30-49 which of the following could be used? descriptive inferential univariate bivariate
descriptive univariate
which statistics summarize and synthesize collected data?
descriptive statisitcs
which type of statistic is this: study of the effect of vitamin C in preventing the common cold. Study determines that 60% of the subjects in the experimental group had fewer colds than the subjects in the control group.
descriptive statisitic
collection and presentation of data that explain characteristics of variables found in a sample
descriptive statisitics
collection and presentation of data that explains characteristics of variables found in a sample
descriptive statistics
statistics that describe, summarize and synthesize collected data (which must be accurate)
descriptive statistics
the collection and presentation of data that explains characteristics of variables found in the sample
descriptive statistics
what type of statistic is used to provide information regarding univariate and bivariate analyses?
descriptive statistics
is this unethical? including information about incidental findings, especially when involving side effects or risks.
ethical
is this unethical? publishing articles about studies with non significant findings
ethical
what kind of experiments use inferential statistics?
experimental or quasi-experimental designs
which type of data collapses the raw data into smaller clasiticiations to make the data easier to interpret?
grouped data
which type of data uses interval/ration level data?
grouped data
when there is a wide variation in data
heterogeneous
the degree to which elements are divers/not alike
heterogenous
which type of multiple regression is this specified importance of variables is included
hierarchical regression
elements that share many common characteristics
homogeneous
when data are very similar and there is little variability
homogenous
when testing for differences between groups, what to researchers need to consider when deciding what test to use?
how many groups what level variables were measured
what principles can we keep in mind when making decisions about hypotheses?
hypothesis are claims about the world decisions are made about the null hypothesis (not the research hypothesis) nothing can be proven, it is supported or unsupported empirical view is adopted (single reality, and science can be used to find the truth)
collection of objectively measurable data that are gathered empirically to confirm or refute a hypothesis empirical testing testing for construct validity
hypothesis testing
an alpha level of .05 ______ type I errors and _____ type II errors
increases; decreases
a variation of the t test used when data values vary independently from one another
independent t test
a variation of the t test where groups/data vary independently from one another
independent t test
analysis of data as the basis for prediction related to the phenomena of interest
inferential statistics
analysis of data as the basis for prediction related to the phenomenon of interest.
inferential statistics
analysis of data as the basis of prediction related to a phenomena of interest
inferential statistics
statistics used to make inferences or draw conclusions about a population based on a sample
inferential statistics
what type of statistics are used to develop population parameters from the sample statistics?
inferential statistics
what type of statistics is used to test this hypothesis: patients with uninterrupted sleep have better wound healing that those who awake during the night
inferential statistics
which statistics analyze the data and make predictions related to the phenomenon
inferential statistics
which type of statistics is this? study of the effect of vitamin C in preventing the common cold. after determining that 60% of the subjects in the experimental group had less colds we use statistics to determine if the difference is significant, if it is then we can determine and infer that taking vitamin C would be beneficial.
inferential statistics
if you understand the SD you can
interpret individual scores in a comparison with other scores in the data set
what are 2 reasons why inferential statistics can be conducted?
make inferences on the population based on the sample test hypothesis
What test is this an example of: m=118.28
mean
the mathematical average calculated by adding all of the data values and then dividing by the total number of values
mean
the mathematical average calculated by adding all of the data values and then dividing the total number of vales
mean
what is the best measure of central tendency? (no extreme values)
mean
what is the most commonly used measure of central tendency?
mean
when data has no outliers researchers prefer to report the:
mean
which measure of central tendency is the most stable?
mean
which 2 measures of central tendency measure continuous-level data
mean and median
measures such as the mean, median and mode that provide information about typical case found in data
measures of central tendency
the mean median, mode that provide information about the typical case found in the data
measures of central tendency
what is another way to describe raw data?
measures of central tendency
measures providing information about differences among data with a set measures of dispersion
measures of variability
measures providing information about differences among data within a set; measures of dispersion
measures of variability
what is the best measure of central tendency when there are extreme values?
median
the number of modes found in a data distribution
modality
the most frequent value in a set of data is?
mode
the most frequently occuring value in a data set
mode
the most frequently occurring data point in a set
mode
as exercise increases, body weight decreases
negative correlation
the increase of a variable is related to the decrease of another variable and vice versa; inverse covary
negative correlation
a distribution where the mean is less than the median and the mode; the longer tail is pointing to the left
negatively skewed
what does a correlation of 0 mean
no relationship
Which LOM has the the raw data represents some characteristics of the variable
nominal and ordinal
inferential statistics using nominal and ordinal data to make inferences about a population
non parametric
what type of test is a chi square?
nonparametric
when results of the study could have occurred by chance; findings support the null hypothesis
nonsignificant
when the results could have occurred by chance; findings support the null hypothesis
nonsignificant
what curve is SD based off of?
normal curve
data representation with a distinct bell curve; data is symmetric around the mean
normal distribution
the mean median and mode are all equal and the data is symmetrical
normal distribution
F=4.65, df=2, 50, p<.05
notation of ANOVA
nonsignificant
ns
in a type I error ________ is rejected when it should be accepted.
null hypothesis
negative z-score indicates
observation is below the mean
inferential statistics involving interval or ratio level data to make inferences about the population
parametric
what kind of tests would you use for: VAS
parametric tests
an inferential statistic used when 2 variables are measured at the interval/ratio level
pearson's r
what test would you use to: determine the relationship between self esteems and weight gain. then determine that self esteem only accounts for 5% of weight gain, thus deducing that other variables must contribute to weight gain.
pearson's r
an inferential statistic used when relationship 2 variables are measured at the interval ratio level
pearson's r (pearson product-movement correlation)
what tests are used for determining relationships/correlations among variables?
pearson's r, multiple regression and kendall's tau
a measure of rank representing the percentage of cases a given value exceeds
percentile
measure of rank representing the percentage of cases that a given value exceeds
percentile
rank
percentile
what are methods to reduce error (4)?
pick designs that fit the question control IV careful measurement of variables reducing threats to internal validity and external validity
which tests normally involve 1 group?
pilot studies
characteristics of a population that are inferred from characteristics of a sample
population parameters
characteristics of a population that are inferred from the 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
calculated by using the formula (n+1)/2, where n is the number of data values in the set
position of the median
as weight increases so does systolic BP
positive correlation
the increase of a variable is associated with the increase of another and vice versa
positive correlation
a distribution in which the mean is greater than the median and the mode the longer tail is pointed to the right
positively skewed
________ is the likelihood of the frequency of an event in repeated trials under similar conditions
probability
likelihood or chance that an event will occur in a situation
probability
the difference between the maximum and minimum in a data set
range
the difference between the maximum and minimum values in a data set
range
what are common measures of variation? (4)
range, semiquartile range, percentile, and standard deviation
what does ANOVA help to decrease?
risk for type I error
rule stating that for every sample 68% of the data will fall within 1 SD of the mean, 95% will fall into 2 SD of the mean and 99.7% will fall within 3 SD of the mean.
rule of 68-95-99.7
numerical data describing characteristics of the sample
sample statistic
numerical data describing the characteristics of the sample
sample statistics
a researchers studies the relationship between Reiki therapy and pain relief. the researcher conducts 7 trials and observes that the statistical results vary greatly from one trial to the next. this variance is an example of:
sampling error
error resulting when elements in the sample do not adequately represent the population
sampling error
error where the elements of the sample do not adequately represent the population
sampling error
the tendency for statistical results to fluctuate from one sample to another
sampling error
what type of plotting of data can provide hints about direction and magnitude?
scatterplots
what can we do to reduce error and increase confidence in findings? (4)
select designs that fit the ? controlling the IV careful measuring of variables reduce threats to internal and external validity
the difference between the 3rd and 1st quartile values, which describes the middle 1/2 of data distribution
semiquartile range
the range of the middle 50% of the data
semiquartile range
a statistically significant correlation is one that is _____
significantly different from 0
asymmetric distribution of the data
skewed
why do researchers attempt to reduce errors?
so we can have confidence in the findings
a measure of variability use to determine the number of data values falling within a specific interval in a normal distribution
standard deviation
a measure of variability used to determine the number of data values falling within a specific interval in a normal distribution
standard deviation
measure of the average deviations of a value to the mean
standard deviation
the most commonly reported measure of variability is the
standard deviation
how is the t test information provided in report?
statistical test done, number of degree of freedom, actual t value and significance level t(2)=2.54, p<.01
results that are unlikely to occur as a result of chance are considered:
statistically significant
when critical values fall in the tails of normal distribution findings did not happen by chance alone
statistically significant
when critical values fall in the tails of normal distributions when findings did not happen by chance along
statistically significant
the numerical outcomes and probabilities derived from calculations of raw data
statistics
what enable researchers to determine that probability that results are not a result of chance along?
statistics
original meaning of statistics meaning "of the state"
statisticum
which type of multiple regression is used to determine the smallest number of IV that account for the greatest proportion of variance in the DV
step-wise
computed value of t test
t
t- test
t = 2.65, p < 0.01
inferential statistic test used to determine whether a statistically significant difference between groups exist
t statistic
inferential statistics test used to determine if a statistically significant difference between groups exist
t statistic
The researcher is trying to determine if the children who use the magic glove while an IV is inserted report less pain than children who do not. Pain is measured using a scale of 0-10. What statistical test should the researcher use? o Chi square o Multiple regression o Pearson's r o t-test
t-test
the degree to which the tail in a distribution is pulled to the left or to the right
tailedness
what is reported in step wise and hierarchical regressions?
the amount of variance that is significant
in chi square what is used to determine if the critical value is significant?
the chi square statistic, the degree of freedom, and the alpha level (then compare to the table)
what does an N-2 degree of freedom mean for pearson's r?
the correlation coefficient can be affected by the sample size
in experimental and quasi experimental designs what is the t test used for?
to determine whether the means of 2 groups are statistically different
delta (amount of change)
triangle
True or false When a probability level is calculated as p<.05 and the researcher has previously set the alpha level of significance at 0.05, the researcher must reject the null hypothesis.
true
true or false although grouping data makes it easier to understand, it results in some loss of information
true
true or false because SD are based on the mean of the data info collected using different measurement scales cannot be directly compared
true
true or false data contained in tables are an important source of evidence for practice
true
true or false due to the instability of the mode it is rarely presented as the sole measure of central tendency
true
true or false errors are avoided when the researchers accept the null when it is true.
true
true or false graphs provide a visual representation of data and make it easier to determine trends.
true
true or false grouped data is more meaningful than raw or ungrouped data.
true
true or false if data is collected and analyzed and the inferential statistics tests are non significant, the null is supported.
true
true or false if the tail of the data is skewed towards the left, then the data are negatively skewed
true
true or false if there is an even number of data points the median is the average number between the two middle most values (even if that number is not found in the data set)
true
true or false in a normal distribution the mean, median and mode are the same value
true
true or false in data comparison the greater the range the more variable the data
true
true or false inferential statistics are best used to determine if there is a difference between groups or a relationship among the variables.
true
true or false it is more risky to claim a treatment works when it actually doesn't
true
true or false magnitude is not dependent on or related to the direction of the correlation
true
true or false nurses should determine that researchers are using the correct statistical test to analyze the data
true
true or false reading the table after the text is a helpful strategy that can improve comprehension of ideas
true
true or false researchers must evaluate data for outliers before performing statistical analyses in order to prove statistical significance of the mean.
true
true or false the alpha level helps to adjust the risk for error
true
true or false the larger the sample size the less an outlier will affect the mean.
true
true or false the mean and median are not necessarily actual data points, and are unique values.
true
true or false the mean is greatly affected by outliers because every data set is used in the calculation
true
true or false the median actually refers to the average position in the data, and is minimally affects by outliers
true
true or false the mode does not mean that a data value occurs more than once in a frequency distribution because the mode is an actual data point.
true
true or false when critical values fall within 3 SD in a normal distribution we can claim findings did not occur by chance
true
true or false when type I error (rejection of null- RA) occurs in nursing the researcher makes false claims about the research hypothesis
true
true or false when type I error increases, type II error decreases
true
true or false with standard deviation information collected using different measurement scales cannot be directly compared
true
true or false descriptive research questions do not require inferential statistics
true
true or false if there are an odd number of data points the median of the scores is exactly in the middle
true
true or false it is possible for a small correlation coefficient to be statistically significant when there is a large sample
true
true or false nonparametric tests are less powerful than parametric tests
true
true or false once the mean is calculated the degree of freedom is lost
true
true or false percentages are often used to describe characteristics of samples
true
true or false post hoc tests are conducted to determine where the significant difference occurred
true
true or false small correlations can be statistically significant because it does not take much variation to be significantly different from 0
true
true or false the F test does not tell the specific group that differed
true
true or false the greater then F statistic the greater the variation between the means of the group
true
true or false the level of confidence related to nonparametric tests is not as strong
true
true or false the range is an unstable measure of variability
true
true or false when only comparing 2 groups the same results would occur between the t test and ANOVA.
true
true or false when parametric tests are used, nurses can have a high level of confidence about the conclusions made
true
true or false correlation coefficients provide information regarding the degree to which variables are related
true
true or false: in data comparison the smaller the range the more uniform the data
true
true or false: the mean and median can be rounded to the nearest number, but the mode cannot be rounded because it is the actual data point
true
true or false the mode is an unstable measure of central tendency
true (varys)
results=statistically significant null=rejected
type I error
what are the more serious error in healthcare?
type I error
when a researcher falsely claims that an intervention works, or that there is a relationship between variables when
type I error
results=failure to obtain statistically significant results null=accepted
type II errors
what are the degrees of freedom used to correct for?
underestimation of population parameters when performing mathematical equations
is this unethical? selection of an alpha of .05 so the researcher hypothesis is supported, because it is not supported at .01.
unethical
what type of data is primarily used to present nominal and ordinal data
ungrouped data
what are 2 questions used to discern if the researcher is using the correct statistical test?
what type of question is being asked? what is the LOM for the variables?
converts standard deviation to a standardized unit
z score
standardized units used to compare data gathered using different measurement scales
z score
what is used to make comparisons among unlike data?
z score
what is used when data collection involves a comparison of the measurement of bone density to obesity measured as a % of body fat?
z score
what measure of variability allows comparison between age and weight?
z score
what are used to compare variablity among data with different units of meausre? (2)
z score variance
mean
M
with two modes
bimodal
What test is this an example of: SD=62.5
Standard deviation
what is used to determine the # of data values that fall within a specific interval in a normal distribution
Standard deviation
branch of mathematics that collects, analyzes, interprets, and presents numerical data in terms of samples and populations
Statisitics
what is the use of a t test?
to determine significance between 2 groups
which measure of central tendency is most often used to compute other statistics?
the mean
which measures of central tendency use continuous level data values for their calculations?
the mean and median
the meaure of the average deviations of a vale from the mean in a given data set
the standard deviation
what 3 pieces of information does this notation for pearson's r show? r=.62, p<.01
the variables are related at a magnitude of .62 (moderate) the variables have a + relationship correlation is statistically significant
how can you determine the mode on a frequency polygon and a histogram?
they have the highest peaks and the tallest bars.
The rule of 68-95-99.7 states that in a normal distribution, 99.7% of the data will fall within ____________ standard deviation(s) of the mean.
three