Chapter 7 - Hypothesis Testing

Hypothesis test

A hypothesis test uses a sample of data in an experiment to test a statement made about the value of a population parameter

Test statistic

The test statistic is a numerical value calculated from the data

Critical region

The critical region is the range of values of the test statistic which will lead to the null hypothesis being rejected

Critical value

The critical value is the boundary of the critical region

One-tailed test

A one-tailed test would test to see if the population parameter has either increased or decreased

Two-tailed test

A two-tailed test would test to see if the population parameter has CHANGED

One-tailed test - accept the null hypothesis 

You accept the null hypothesis when the probability calculated is greater than the significance level 

Probability > significance level

One-tailed test - reject the null hypothesis 

You reject the null hypothesis when the probability calculated is less than the significance level 

Probability < significance level

One-tailed test - when observed value falls in the critical region

You reject the null hypothesis when the observed value is in the critical region

One-tailed test - when observed value does not fall in the critical region

You accept the null hypothesis when the observed value is not in the critical region

Two-tailed test - accept the null hypothesis

You accept the null hypothesis when the probability calculated is greater than the significance level 

Probability > significance leve

Two-tailed test - reject the null hypothesis

You reject the null hypothesis when the probability calculated is less than the significance level 

Probability < significance level

Two-tailed test - when observed value falls in the critical region

You reject the null hypothesis when the observed value is in the critical regio

Two-tailed test - when observed value does not fall in the critical region

You accept the null hypothesis when the observed value is not in the critical regio