PSYC 2021 Lecture Notes - Null Hypothesis, Standard Deviation, Statistical Hypothesis Testing
22 Dec 2013
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Document Summary
Power of statistical test: probability of rejecting false null hypothesis: reject" or fail to reject" only applies to h0 t-statistic. Estimated sample error (sm): sm = s/(sqrt. of n, use it when you don"t know of population tobserved =(m- )/ sm. If sample size is huge, t" distance becomes the same as z" distance. t-distribution is flatter than normal distribution (has heavier tails) We estimate population standard deviation with sample standard deviation. More difficult to reject the null in the tails (critical values are more extreme) In hypothesis testing, we must know the degrees of freedom to indentify the critical value tcritical value is a score defined by alpha. If the p value is small, we reject h0. The probability of getting mean of the sample given the population is unchanged. P-value is the probability of obtaining mean, assuming the null holds.
