chap 8 terms

# chap 8 terms - level of significance: The level of...

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Chapter 8 New Terms and Concepts The following terms were introduced in this chapter. You should be able to define or describe each term and, where appropriate, describe how each term is related to other terms on the list. hypothesis testing: A statistical procedure that uses data from a sample to test a hypothesis about a population. null hypothesis, H0: The null hypothesis states that there is no effect, no difference, or no relationship. alternative hypothesis, H1: The alternative hypothesis states that there is an effect, there is a difference, or there is a relationship. Type I error: A Type I error is rejecting a true null hypothesis. You have concluded that a treatment does have an effect when actually it does not. Type II error: A Type II error is failing to reject a false null hypothesis. The test fails to detect a real treatment effect. alpha (α): Alpha is a probability value that defines the very unlikely outcomes if the null hypothesis is true. Also, alpha is the probability of committing a Type I error.
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Unformatted text preview: level of significance: The level of significance is the alpha level, which measures the probability of a Type I error. critical region: The critical region consist of outcomes that are very unlikely to be obtained if the null hypothesis is true. The term very unlikely is defined by . test statistic: A statistic that summarizes the sample data in a hypothesis test. The test statistic is used to determine whether or not the data are in the critical region. beta (): Beta is the probability of a Type II error. directional (one-tailed) test: A directional test is a hypothesis test that includes a directional prediction in the statement of the hypotheses and places the critical region entirely in one tail of the distribution. effect size: A measure of the size of the treatment effect that is separate from the statistical significance of the effect. power: The probability that the hypothesis test will reject the null hypothesis when there actually is a treatment effect....
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## This note was uploaded on 04/08/2011 for the course PSY 216 taught by Professor Cynthiaingle during the Spring '11 term at KCTCS.

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