Latona did an experiment at a military barracks over the space of a few months to examine the effect of group size on group morale. He randomly assigned soldiers to the experimental and control groups and did a pretest and posttest. Midway through the experiment, some of the soldiers were re-assigned to different stations across the U.S. causing the sample size to drop. Which source of internal

Question

invalidity does this example reflect?

a. history
b. maturation
c. instrumentation
d. selection biases
e. mortality

Answer 1

E