Logic and Vocabulary Logic and Vocabulary of of

Hypothesis TestsHypothesis Tests

Chapter 13Chapter 13

Hypothesis Testing LogicHypothesis Testing Logic

Assume a value for a parameter.Assume a value for a parameter.

Collect sample data to test the Collect sample data to test the assumption.assumption.

Draw a conclusion about the Draw a conclusion about the parameter.parameter.

VocabularyVocabulary

The Null Hypothesis (Ho): The statement about a parameter that we assume is true. It must contain equality. It is the statement that is tested.

VocabularyVocabulary

The null hypothesis is the statement of ‘no effect’ or ‘no difference’ from the null value.

VocabularyVocabulary

The Alternative Hypothesis (Ha): The “research” statement. It is usually what we think might be true and hope to find evidence to support.

VocabularyVocabulary

If we find evidence against Ho, then we are in favor of Ha.

If Ho is rejected, then the test is ‘statistically significant’.

VocabularyVocabulary

The Test Statistic is a standard score, computed from data and based on assuming Ho is true.

VocabularyVocabulary

The P-value is the probability of observing our statistic or one more extreme in the direction of Ha.

The smaller the P-value, the stronger the evidence against Ho.

VocabularyVocabulary

The P-value is the area in the appropriate tail(s) of the sampling distribution. The tail desired depends on Ha.

VocabularyVocabulary

The significance level is denoted by . We will reject Ho when the P-value is less than . We’ll usually use = 0.05 but other common values are 0.01 or 0.10.

Hypothesis Testing ProcedureHypothesis Testing Procedure

Define parameters and state HDefine parameters and state Hoo and and HHaa..

Check conditions.Check conditions.Calculate the test statistic.Calculate the test statistic.Find the P-value.Find the P-value.Write a conclusion in context.Write a conclusion in context.