4. Reaction Times II The experiment in Exercise 1 might have been conducted more effectively using a randomized block design with people as blocks, because you would expect mean reaction time to vary from one person to another. Hence, four people were used in a new experiment, and each person was subjected to each of the five stimuli in a random order.

The reaction times (in seconds) are listed here:

a. Use the Excel printout to analyze the data and test for differences in treatment means.

b. Use Tukey’s method of paired comparisons to identify the significant pairwise differences in the stimuli.

c. Does it appear that blocking was effective in this experiment?

Transcribed Image Text:

Subject A Stimulus B C CDE 1 .7 .8 1.0 1.0 .5 2 .6 .6 1.1 1.0 .6 3 .9 1.0 1.2 1.1 .6 4 .6 .8 .9 1.0 .4 Anova: Two-Factor Without Replication SUMMARY Count Sum Average Variance A 4 2.8 0.7 0.02 B 4 3.2 0.8 0.0267 4 4.2 1.05 0.0167 D 4 4.1 1.025 0.0025 E 4 2.1 0.525 0.009 ANOVA Source of Variation SS df MS F P-value F crit Rows 0.14 3 0.046667 6.588 0.007 3.490 Columns 0.787 4 0.196750 27.776 0.000 3.259 Error 0.085 12 0.007083 Total 1.012 19