Advantage of using repeated measures - ✔✔✔ANSWER-Same individuals in all
treatment conditions
-only need half the participants
-Able to take out individual characteristics
Advantages of a Directional Hypothesis - ✔✔✔ANSWER--Increased power to
detect the specific effect you are interested in
Advantages of a repeated measures design - ✔✔✔ANSWER-One person is used
for for both experiments
More statistical power:
-Repeated measures designs can be very powerful because they control for factors
that cause variability between subjects.
Fewer subjects:
, -Thanks to the greater statistical power, a repeated measures design can use
fewer subjects to detect a desired effect size. Further sample size reductions are
possible because each subject is involved with multiple treatments.
ex) If an independent groups design requires 20 subjects per experimental group,
a repeated measures design may only require 20 total.
Quicker and cheaper:
-Fewer subjects need to be recruited, trained, and compensated to complete an
entire experiment.
Assess an effect over time:
-Repeated measures designs can track an effect overtime, such as the learning
curve for a task. In this situation, it's often better to measure the same subject at
multiple times rather than different subjects at one point in time for each.
Alpha Level - ✔✔✔ANSWER--Probablility that a a test will lead to a Type 1 error if
the null is true
-Determines probability of obtaining a sample even if there is no treatment effect
Appropriate use of T tests - ✔✔✔ANSWER--To determine the population of a
sample
-Analysis of two populations means through the use of statistical examination
-t-test with two samples is commonly used with small sample sizes, testing the
difference between the samples when the variances of two normal distributions
are not known.
*Used when the variance for the population is unkown