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Unformatted text preview: Psychology 206 Class Notes 11/19/08 What is good about one-tailed (directional) hypothesis tests? o With one tailed test, you would reject the null hypothesis compared Its slightly more likely that you would reject a null hypothesis (more accurate) With a one tailed test, you have a greater power to detect an effect if your Z is not large you will be able to reject the null hypothesis What is bad about one-tailed (directional) hypothesis tests? o If you are totally wrong about your hypothesis o If you make a 1-tailed test, you can miss an effect entirely (it could be on the opposite side) A treatment could be making a patient better, but it might be harming the patient worse (other end of the distribution) It is for this reason why we DO NOT typically use 1-tailed tests! Exercises #25 and #26 Problems with wording of null hypothesis:- The mean of the population of body temperatures of students- The mean of the population of cost per mile...
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This note was uploaded on 06/03/2009 for the course PSYCH 206 taught by Professor Kenney-benson during the Fall '07 term at Allegheny.
- Fall '07