Purpose: to allow you to demonstrate that you can produce a statistical analysis, interpret the results, and describe what you have learned in both technical and non-technical terms.

Bliss, Statistics in Biology, v.1, contains data collected by Linder and Grandjean on the threshold of patellar reflex measured on eight successive days. Data shown here are for Subjects A, D, and H, in millisec.

Thresh Subj.

34 A Enter the data in Col. 1, and the subject code in Col. 2 in the data window. Check!

26 A

28 A Produce an ANOVA, dotplot, and plot of residuals vs. fits. Follow the first-day

23 A handout directions "Using MINITAB for …." except that ‘Time’ becomes ‘Thresh’

22 A and ‘Treatment’ becomes ‘Subj.’

26 A

28 A Take logs of the data. Calc>Calculator Store result in: c5 Expression: log(c1)

23 A Give Column 5 a name, such as lgThresh.

59. D

66 D Repeat the analysis Stat>ANOVA>Oneway using Column 5 as the response.

60 D This time, in Graphs put Ö in "Residuals versus order".

56 D

58 D This will give you the same analysis steps as the original one, plus a plot of residuals

56 D vs. time order (1-8 is Days 1-8 for Subject A, 9-16 is Days 1-8 for Subject D, ….)

55 D

54 D If you get stuck at any point, try Help either overall, or in the dialog box.

112 H

107 H Write a report which covers these items.

120 H

148 H 1) Briefly describe the experiment.

117 H

117 H 2) Which scale (y or log y) best satisfies the equal variance assumption? (Justify.)

141. H

126 H 3) Which scale gives the strongest evidence that population means are unequal? (Justify.)

4) What do you conclude about the independence of errors over time? (Justifiy.)

5) Estimate each subject’s threshold with a 95% conf. int. in the most appropriate scale.

6) Any additional observations or conclusions you may have. (Optional)

7) Conclusion(s) and Recommendation(s)

Report Format:

-Executive Summary, at most one page.