# NURS341 Lecture Notes - Lecture 5: Statistical Significance, Statistical Hypothesis Testing, Sample Size Determination

## Document Summary

Is there a difference between the means of two groups: h0: x1= x2, h1: x1 (cid:454)2. It is the cut off for considering statistical significance in a particular study: p-value, computed during a study. Probability that the results (i. e. test statistic, relationship, association, difference) are due to chance: researchers decide to reject h0 (null hypothesis) if the p value is less than a. Statistical testing: statistical testing is used to determine the probability of error in rejecting the null hypothesis. If p-(cid:448)alue of test is 0. 05, do not reject null (not statistically significant) If p-value of statistical test is < 0. 05, reject null (statistically significant: statistical significance, note: you cannot have a negative p-value! To 0. 1: changing the likelihood of type i error. Alpha = 0. 05 so finding is statistically significant because p-value is less than alpha. Lot of tests = strongest alpha such as 0. 01.