Unformatted text preview: Pop. 2)-Example o Null vs. Research Null: Men and women do not differ in IQ scores (Pop 1 = Pop 2) Research: Men and women do differ (Pop 1 ≠ Pop 2) If null is not rejected, research is inconclusive-Null Hypothesis Testing (NHST) steps o State both hypothesis o Using mean, and SD of comparison population, determine your sample’s Z score on the comparison distribution. o Decide whether to reject the null hypothesis based on the traditional cut off level of 0.05. o If null is true, chances are that sample mean will fall between your critical values. (See picture on slide) o Using a cut off level (alpha) of .05 (5%) where 95% in normal distribution is between +/- 1.96 standard scores. o Called the 5% level of significance o...
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- Spring '08
- Null hypothesis, Statistical hypothesis testing, 5%