EXERCISES FOR CHAPTER 14
NOTE: For the first group of exercises, labeled “a, ” assume independent scores.a1. What should be done to avoid possible hurt feelings and distress by a human subject who is eliminated from the experiment for failing to meet some screening criterion?a2. Under Methods for Language Learning
(Section 14.2.2), explain the sentence, “This was verified, Fblocks
being even a little larger than Fmethods
.”a3. Q included successive, temporal blocks in her design and found Fblocks
= 2.67 on 3/16 df. What should she make of this?a4. P used block randomization in six successive, temporal blocks in an experiment in which previous work clearly indicated that block effects were not substantial. P did not include blocks in his factorial Anova of the main treatment variables. By a priori plan, however, he did test the main effect of blocks, using the hand formulas of Section 3.2.5 to get SSblocks
, which he tested against MSerror
from the overall Anova.
|a. ||What are two objections to P's test of the block effect?|
|b. ||What would P say about these two objections?|
|c. ||Suppose P found a large effect of blocks. Would that require any qualification of his main analysis?|
|d. ||Do you think P erred in not including blocks in his factorial Anova?|
a5. Design an experiment in your area in which you would use the initial phase to increase reliability and validity of the response measure. Specify exactly how you would expect each advantage to be realized.a6. In the field study of smoking prevention cited in the Appendix to Chapter 3, the effect at 12 months was not large.
|a. ||How might the screening procedure be amplified to screen out more of the probable relapsers?|
|b. ||What advantage might be expected from (a)?|
a7. The last paragraph under Screening Tests states that limiting the subject population can increase process validity. Cite two different situations in which you could expect such increases.