PSYCH 240 Lecture Notes - Lecture 7: Null Hypothesis, Type I And Type Ii Errors, Statistic
29 Nov 2016
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If the probability is high, we have no real evidence in favor of the hypothesis. Or does not = > two sided alternative. We don"t try to prove the alternative, but we want to reject the null hypothesis. The null hypothesis is as if nothing was happening, so we want to prove that there is something happening. Basic steps of significance testing: compute the probability of getting a sample statistic if the null hypothesis were true, compare the p-value to a predetermined cutoff called the -level. If our p-value is less than our - level, we reject the null hypothesis in favor of the alternative hypothesis. To figure out the probability of getting a sample statistic. You figure out what the sampling distribution of that statistic would look like if the null hypothesis were true. You then look at the actual sample statistic you got, and figure out how likely that particular value (or a more extreme one) is.
