Day 8 slides Flashcards
descriptive statistics refers to the what?
the population
inferential statistics refers to what?
the sample
what things does inferential statistics include?
CI, p-value, hypothesis testing
What can you inferential stats allow you to do?
infer things about larger population from the sample
P-value of less than what is statistically significant?
less than 0.05
a smaller standard deviation means what?
more certainty
what things should you consider when trying to consider if a study is significant?
- larger difference between means
- smaller SD= more certainty
- appropriate sample size
what are confidence intervals?
how accurate this estimate is for the whole population
what type of data are CI’s used for?
interval or ratio
how do you increase CI?
- increase sample size
- narrow the variance
- reduce random measurement errors
Why does increasing sample size help?
a bigger sample gives us more confidence in the result and that it can be applied to a larger population
What does it mean to narrow the variance?
more homogenous sample risks limiting generalizability
What does a CI actually tell us?
confidence intervals tell us what our best guess is for the size of the population effect, 95% of the time
What does a p-value of 0.05 actually mean?
it means that the result could have occurred by chance less than 5% of the time, therefore it is likely due to some relationship
What is a t-test?
compare two means (significant difference)
What is an independent samples t-test?
comparing two different things
What is a paired samples t-test?
pre-test/post-test; before and after comparing the same thing
What is a one-tail approach?
there is no real risk for harm, so you only have space to gain; will be seen in a positive distribution
-all 5% is improvement
What is the two-tailed approach?
2.5% in either direction (may be harmful or helpful)
When must you determine if you are doing a one tailed or two tailed approach?
must be determined in advance before doing the test
what does POEM stand for?
patient-oriented evidence matters
What is patient-oriented evidence?
deals with outcomes of importance to patients, such as changes in morbidity, mortality, or QOL
What does DOE stand for?
disease oriented evidence
What is disease oriented evidence?
deals with surrogate and points, such as changes in laboratory values or other measure of response
