2. Rationale / value of using statistics statistics is a powerful tool to objectively compare experimental data uncover relationships among variables experience an aspect of the practice of science – like real scientists prepares you for a statistics course, a common math class taken in college

3. Characterization of experimental data is the SD in the distribution of means; used in statistical tests. standard error of the mean (SEM) = is a measure of the variation in the data. sample standard deviation (SD) = is the average value in the above graph. sample mean =

4. Elimination of outliers: Q-test Q = N (sample size)QcQc 3 4 5 6 7 8 9 10 0.94 0.76 0.64 0.56 0.51 0.47 0.44 0.41 For example: is the value of 25 an outlier in the following data set ? 10, 11, 13, 14, 25 In this example, Q = thus, the value of 25 is an outlier and may be deleted in subsequent data analysis. The Q-test should be used to deleted only a single data. Table 1. Q c values. Outlier data that significantly differs from others its deletion would reduce variability in the data its deletion may make it easier to detect differences between experimental conditions delete if Q > Q c