Use of a pretest as well as a posttest, rather than a posttest by itself, is valuable because
a) One can evaluate and statistically adjust for any pretest sensitization effect.
b) One can use a directional test to evaluate change, i.e., did patients improve.
c) Reduces bias due to multiple statistical tests
d) The error term is reduced in the statistical test and power is increased.
Question 2How can power be augmented in an investigation?
a) Through the use of posttests
b) Through maintaining conventional levels of significance
c) Through the use of directional tests
d) Through controlling the side effects of treatment
Question 3Which of the following is a valid method of determining the necessary sample size of an investigation?
a) Through the effect size, alpha, and power
b) Through the clinical significance of an investigation
c) Through conventions in his or her field of research
d) Through the use of significance tests
Question 4What is power?
a) An objection to the use of significance testing in psychological research
b) The expression of differences between groups in a common metric
c) The probability of accepting the null hypothesis when it is false
d) The extent to which a difference can be detected when a difference exists
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