CH 14 - Exam 2 Flashcards
Can research studies still be published or peer reviewed if they use the wrong type of statistical test or measure to analyze its study?
no
What are the 5 levels of measurement
- nominal
- ordinal
- interval
- ratio
- continuous variable
A ___ measure is the lowest level of measurement and involves using ___ to designate attributes
- nominal
- numbers
Can the numeric indicators used in a nominal study be used mathematically
no
___ measurements rank people based on an attribute, where the number relates to the rating of the attribute
ordinal
___ measurements rank people on attributes with a number that clearly specifies a distance b/t the two
interval
An IQ is an example of what type of level of measurement
interval
___ measurements are the highest level, and the numbers included are able to have a meaningful zero
ratio
Ratio measures have 2 values that can be accurately described by their ___
ratio
___ ___ are variables with interval and ratio measurements
continuous variables
Descriptive statistics are used to ___ and ___ data
synthesize and describe
Parameters are ___ values such as ___ and ___
- calculates
- percents
- averages
A ___ is a descriptive index from a sample
statistic
A frequency distribution takes a list of values and organizes it ___ to ___ and includes a ___.
- lowest to highest
- count
Symmetric distributions are ones where if the graph is folded in 1/2 it would be ____.
superimposed
A skewed distribution the majority of the data ___ to ___ ___
peaks to one side
A normal distribution has a ___ ___ which has a ___ peak than other types of distribution
bell-shaped curve
lower
___ attributes tend to have a bell shaped curve
Ex:
- human
- height and intelligence
___ ___ includes methods to determine a central value for a set of numbers
central tendency
When measures of central tendencies are the same for two different sets of distribution it is know as ___
variability
___ ___ is a variability index calculated based on every value is a distribution
standard deviation
Standard deviation is the ___ amount of deviation of values from the ___
- average
- mean
The lower the standard of deviation the more ___ the distribution
- homologous
For normal distribution what percentage of values will be within the first standard of deviation?
The 2nd?
- 68%
- 95%
If a frequency distribution is based on 3 variables a ___ ___ can be used to depict the data
crosstabs crosstable
cross tabulations use __ variables ___ statistics, can can be used with ___ or ___ data
- 2 variables
- descriptive
- nominal
- ordinal
Correlations are methods to describe ____ between 2 ___
- relationship
- variables
The ___ ___ describes the intensity and direction of the relationship between two variables
correlation coefficient
What is the range for correlation coefficients?
What do the numbers indicate?
- range : -1 - +1
- 0 - +1 = a positive relationship
- -1 - 0 = a negative relationship
The most widely used correlation stat is ___ __ (the product moment correlation coefficient)
Pearson’s r
Spearman’s ___ is a correlation coefficient calculated for values on an ___ scale
- rho
- ordinal
A ___ ___ displays correlation coefficients in tables
correlation matrix
What is absolute risk
the proportion of people who actually experienced an undesirable outcome in each group involved in the study.
What is absolute risk reduction?
when you subtract the value of absolute risk of the control group from the absolute risk value of the test group
What is the odds ratio?
the odds of an undesirable event : divide the number of people who did not experience AE by those who did –> this value can be used to compare the 2 groups
What is the number needed to treat
an estimate of how many people need to receive an intervention to prevent one undesirable outcome (1 divided by the absolute risk)
___ statistics use the law of probability to test research hypotheses with data
inferential
A ___ sample size helps reduce the risk of outlying data
large
___ ___ of the ___ = standard deviation of the mean of a sample
standard error of the mean (SEM)
A \_\_\_ (high/low) SEM is associated with more error associated with the sample selected Therefore a \_\_\_ SEM reflects a more appropriate sample size
- higher
- lower
parameter estimation is used to estimate a ___ ___ such as the __
- population parameter
- mean
A ___ ___ relates to the probability of the parameter estimation being correct
confidence interval
What is the goal for a confidence interval (%)
95-99%
Hypothesis testing uses ___ ___ to determine if the hypothesis is supported to rejected
objective criteria
A null hypothesis is when there is ___ ___ between the ___ and ___ ___
- no relationship
- independent and dependent variable
Rejecting a null hypothesis that is true is a ___ ___ ___
type one error
When the null hypothesis is assumed to be true when in fact the independent variable did have an effect is a __ __ __
type 2 error
level of significance is indicated by the __ or a ___
alpha or designation
The level of significance is calculated by :
subtracting the confidence level from 1
To reduce the risk of a type to error you should
increase the sample size
A ___ __ is calculated to determine the chance of a type 2 error
power analysis
What is the goal for a power analysis?
What does this indicate?
- goal = 0.8
- indicates there is a 20% chance of a type 2 error
Since it is impossible to eliminate the possibility of errors studies aim to be ___ ___
statically significant
- If a study is statically significant it mean that the …
- Statically significant values should fall w/I __ standard deviation(s) of the mean
- Confidence intervals of ___ or greater are considered statically significant
- results did not likely occur by chance
- 2
- 95%
What test should be used when testing the difference b/t 2 group means
t-test
what value determines if the results are significant
p value (<0.05)
___ t tests are appropriate for two different groups of people
independent
___ t tests are used when one group is tested at two different points in time
paired
What test is used to test mean group differences of 3 or more groups
Analysis Of Variance ANOVA - calculates a F value which we use to find a p value
What test focuses on the difference in proportion
chi-squared - still use p value
___ ___ measures several independent variables, where the independent variables are called ___
- multiple regression
- predictors
a multiple correlation coefficient AKA __, it has a range of ___ to ___
R
0.0 - 1.0
R squared gives a ___ of how influential the ___ were
A high R squared indicates
- percentage, predictors
- high R squared = the predictors were more likely to account for the variation
What is Analysis Of Covariance (ANCOVA)
When is it good
What does it attempt to do?
- a combination of ANOVA and multiple regression
- good when no control through randomization
- control covariates of cofounding variables
___ ___ analyzes the relationship b/t multiple independent variables
logistic reasoning
logistic reasoning will yield ___ ___ for each ___ variable as well as ___ ___
- odds ration
- independent
- confidence interval
What are 3 reliability measurements
- test retest reliability
- interrater reliability
- internal consistency reliability
____ ___ ___ is used for test retest reliability and ranges from 0-1 where 1 indicates __ reliability
- interclass correlation coefficient
- strong
___ ___ is used in interrupter reliability and determine dichotomous classifications
Cohen kappa
__ __ would be helpful to determine if two individuals would rate something similarly
choens kappa
Internal consistency reliability uses __ or __ alpha
- coefficient
- Cronbach’s
___ ___ is used to measure how often components of a multicomponent toll measure the same attribute
coefficient alpha or Cronbach’s alpha
___ ____ determine if the content of the items adequately reflect the construct of interest
Should be __ or higher
- content validity
- 0.90
___ ___ concerns the extent to which scores on a measure are consistent with a gold standard criterion
This has 2 types :
- criterion validity
- sensitive and specificity
Sensitivity is the ability …
of a measure to correctly screen or diagnosis a condition
Specificity is the…
measures ability to correctly identify non-cases or screen out those without the condition
___ ___ concerns the extent to which a measure is truly measure the target construct
construct validity –> uses various procedures
