Quantitative Methods 2017

Terminology

• Null hypothesis, H 0

• The hypothesis of no difference

• Alternative hypothesis, H 1 • The hypothesis, that there is a difference • The expected difference is used to calculate β • Significance level, α • The risk of rejecting the null hypothesis if it is true • Normally 5% (p=0.05 is significant) • Statistical power, 1-β • The probability of rejecting H 0 if H 1 is true • Often 80%, recommended 90% • Depends on α and assumed effect size