Type 1 and Type 2 Error Flashcards
1
Q
Type 1 error
A
Type I: the null hypothesis is rejected when it is true (finding a difference that didn’t exist), this is also called a false positive. This is determined against a preset significance level (termed alpha). As the significance level is determined in advance the chance of making a type I error is not affected by sample size.
2
Q
Type 2 error
A
Type II: the null hypothesis is accepted when it is false (failing to find a difference that really existed), this is also called a false negative. The probability of making a type II error is termed beta. It is determined by both sample size and alpha.
