To understand just what happened in the experiment involving the training of severely developmentally handicapped children (Exercise 14.3), our original experimenter evaluated a third group at the...

To understand just what happened in the experiment involving the training of severely developmentally handicapped children (Exercise 14.3), our original experimenter evaluated a third group at the same times as he did the first two groups, but otherwise provided no special treatment. In other words, these children did not receive reinforcement, or even the extra attention that the control group did. Their data follow:

a. Add these data to those in Exercise 14.3 and rerun the analysis.

b. Plot the results.

c. What can you conclude from the results you obtained in parts (a) and (b)?

d. Within the context of this three-group experiment, run the contrast of the two conditions that you have imported from Exercise 14.3.

e. Compute the effect size for the contrast in part (d).