What are the two ways that data are collected?
Observational study
Designed experiment
Describe an observational study
Record measurements without control over how they are produced
Describe a designed experiment
You control the conditions that create the measurement
What are the two properties of estimators we want to have?
Unbiased
The more data we collect, the more precise our estimate should become
What properties does the sample mean have?
Unbiased and consistent estimator of the population mean
What properties does the sample variance have?
Unbiased estimator of the population variance
What is a type I error?
Reject H0 when H0 is true
What is a type II error?
Fail to reject H0 when H0 is false
What is the p value?
Probability of observing a test statistic T at least as extreme as the observed test statistic, t, given the null hypothesis is true