Critical Numbers Flashcards
what is statistical significant? and how is it quantified?
Statistical significance is the likelihood that a relationship between two or more variables is caused by something other than chance.
Statistical significance is used to provide evidence concerning the plausibility of the null hypothesis.
It is quantified via a P-value
what is the P-value?
the probability of seeing a different outcome, is the null hypothesis is accepted. E.g. the chance something that is not the null occurs
what does a null hypothesis assume?
when comparing two groups the Null assumes there is no difference between the groups
what does a P-value of 0.001 mean?
would see a difference from the Null 1 time in 1000, if the Null was true.
what is the 95% confidence interval?
The 95% confidence interval defines a range of values that you can be 95% certain contains the population mean
A study is designed to examine the relationship between blood pressure and job. What could be a confounding factor?
Age
What is a cohort study? give an example
Cohort studies typically observe large groups of individuals, recording their exposure to certain risk factors to find clues as to the possible causes of disease.
The Nurses’ Health Study is one example of a large cohort study, and it has produced many important links between lifestyle choices and health by following hundreds of thousands of women across North America.
what happens to the standard error as the sample size increases
standard error decreases
When is sampling bias likely to occur
when certain individuals are more likely to be included in the study than others.
