Biostatistics 2 Flashcards
Define Research Question
Guides and centers the research
Define Scientific Hypothesis
A proposed explanation for a given phenomenon
Educated Guess
Define Experimental hypothesis
Predicted observation you will obtain from an experiment
Define Null Hypothesis
Ho: u1 =u2
Define Alternative Hypothesis
H1: u1 doesn’t = u2
H1: u1 > u2
Define Random error
Unknown/unpredictable change in a study
Define systematic error
Bias in measurement
Measuring Random Error
P value gives probability of being wrong when the null is rejected
Does NOT give you magnitude
Power gives the probability of making a correct decision when null is truly false
What is a p value
How confident are you that the difference you found between or among groups are due to chance?
What is the alpha value?
What threshold are you comfortable with saying that an observed difference was due to your intervention and not chance?
This is the value your p value must be below to be considered statistically significant
What is power?
If you do not find a difference between drug and placebo, how confident are you that the difference is not there?
Ability to detect a difference if one truly exists
Factors that effect power are?
Willingness to accept a Type 1 error
Effect size
Beta error
Sample size
**Power ONLY matters if…
the researcher did NOT find a statistically significant result
