significance tests

p value

probability of getting evidence for the alternative hypothesis as strong or stronger than the observed evidence when the null hypothesis is true

if the p value is small

reject the null and conclude there is convincing evidence to support the alternative

if the p value is not small

fail to reject the null and conclude there is not convincing evidence for the alternative

significance level

the value we use as a boundary for deciding whether an observed result is unlikely to happen by chance alone when the null hypothesis is true

type I error

rejecting a true null

type II error

failing to reject a false null

the probability of making a type I error in a significance test is equal to

the significance level

standardized test statistic

measures how far a sample statistic is from what we would expect if the null hypothesis were true

standardized test statistic formula

power

the probability of making a type I error

how to increase power

increase sample size and significance level