EBP Exam II Flashcards
What is a sample size?
the number of participants in a study
what is the “power” of a study?
it’s ability to show results
80% = 8/10 people in the study will get the expected result
What determines the sample size?
power analysis
What are the types of RANDOM sampling?
simple
stratified
What are the types of NON-RANDOM sampling?
Convenience
Purposeful
Snowball
What is simple sampling?
random
every participant is chosen by chance
What is stratified sampling?
random
create subgroups and take a random sample from each subgroup
What are the goals of sampling?
unbiased and representative
What is convenience sampling?
non-random
sample is easy to reach/find
What is purposeful sampling?
non-random
based on selected characteristics
What is snowball sampling?
non-random
participants in one study suggest future participants
What is random assignment associated with?
INTERNAL validity
What IS random assignment?
assigning your sample population to the control or intervention group
What does “observation” data encompass?
direct observation of behavior or characteristics
What are biophysiological data?
IDEAL data
What are the types of biophysiological data?
in-vivo: measuring factor inside a person (BP, HR)
in-vitro: taking stuff out. of a person (blood test, urinalysis)
anthropomorphic: person’s characteristics
What are the types of self-report data?
questionnaire and interview
Describe a psychometric scale:
assigns number to a measurement (very common)
Describe the Linkert Scale:
agree to disagree scale
Describe the Visual Analog Scale:
picture responses instead of numbers
Reliability = \_\_\_\_\_\_ Validity = \_\_\_\_\_\_
reliability = consistency validity = accuracy/reality
a study can be ____ but not _____
reliable but not valid (broken scale)
What is described when you get the same results every time a measure is used?
reliability
What is described when the measure is appropriate for the question?
validity
What are 3 approaches to measuring reliability?
Inter-rater
Test-retest
Internal consistency
What is inter-rater reliability?
two people using the same measure to get the same results
What is test-retest reliability?
measuring at different times and getting the same result
What is internal consistency reliability?
questions on a scale to assess the same thing (Chonbach’s alpha)
What are the 3 ways to measure validity?
content (face) validity
criterion (predictive) validity
construct validity
What is content validity?
face validity
how comprehensive the items on a scale are in measuring what it’s supposed to measure (how good is this scale in measuring depression?)
What is criterion validity?
predictive validity
the extent to which the results of a measure are related to similar measures (Do both of these depression scales measure depression similarly?)
What is construct validity?
how well does a scale measure what it’s supposed to measure?
What is the difference b/w conceptual and operational definitions of a variable?
conceptual: defines what a variable is
operational: defines how to measure a variable
What is a confounding variable?
a variable you didn’t account for that has an impact on both the IV and the DV
What are biophysical measures?
data driven by technology
What is allocation concealment used for?
to stop/mitigate against selection bias
it is difficult to change ____ data into ___ data.
ordinal into interval
can you move down in level of measurement?
yes, but never up
ex. you can move from ordinal to nominal data but never nominal to ordinal
Rank the levels of measurement from most to least specific.
Ratio
Interval
Ordinal
Nominal
What is an example of ratio data?
age or height
they start at zero
What is an example of interval data?
time of day, IQ
What is an example of ordinal data?
pain (good/neutral/bad)
height (short/average/tall)
What is an example of nominal data?
state of Florida
gender
What is the difference between descriptive and inferential statistics
Descriptive = one variable is described at a time Inferential = looks at the magnitude of a relationship between two variables
Define relationship vs. difference
relationship: has a direction (+ or -) and a strength (“r” variable)
difference: looking at the difference b/w two groups in regards to their “means” or “risk”
What p value supports that the relationship (difference) is statistically significant?
p < 0.05
what does p > 0.05 mean?
there is a true relationship between variables
What are factors of normal distribution?
symmetric
unimodal
mean=mode
What is correlation?
the strength of the relationship
effect size determines:
clinical significance
p value determines:
statistical significance
Why is effect size important?
it measures the magnitude of difference between groups
How can we present effect sizes?
Cohen’s D
Odds Ratio
R2
Which odds ratio is meaningful?
O=2
What is R2?
percent of shared variation.
What is odds ratio?
difference in proportions
What is Cohen’s D?
difference in means
Effect size is NOT based on _______
sample size
What does a forest plot present?
all effect size variables
What is variance?
average distance of all scores from the mean score
What is standard deviation?
the square root of the variance
What are standardized scores?
scores transformed to be on a common scale
What does a horizontal line mean on a forest plot?
there is NO difference/relationship
Effect size allows for ____________
comparisons across different studies
Variables are measured in which two ways…
Concrete: temperature, weight
Abstract: Creativity, empathy
What are the 3 types of variables? And what they do?
Descriptive: Confound; Control (adjust or take away effect)
Independent: Cause or Predictor
Dependent: Effect or Outcome
Statistics are used to assess what?
Relationships
