STAT 2507 Lecture Notes - Lecture 9: Type I And Type Ii Errors, Null Hypothesis, Alternative Hypothesis
Document Summary
Chapter 9, 10 z hypothesis testing: similar to a courtroom trial. In trying a person for a crime, the jury needs to decide between one of two possibilities: The two competing hypotheses are the alternative hypothesis ha, generally the hypothesis that the researcher wishes to support, and the null hypothesis h0, a contradiction of the alternative hypothesis. The researcher uses the sample data to: reject h0 and conclude that ha is true, accept (do not reject) h0 as true. Test statistic: a single number calculated from the sample data. p-value: a probability calculated using the test statistic. Rejection region: one set, consisting of values that support the alternative hypothesis and lead to rejecting h0. Accepting region: one set, consisting of values that support the null hypothesis. Critical values: the value that separate the acceptance and rejection regions. A type i error for a statistical test is the error of rejecting the null hypothesis when it is true.