For each description below, identify the independent variable(s): ·         Subjects are randomly assigned to one of three rooms of different size (small, medium, large) to complete a puzzle. Time to...

For each description below, identify the independent variable(s):

·         Subjects are randomly assigned to one of three rooms of different size (small, medium, large) to complete a puzzle. Time to complete the puzzle is measured.

·         Subjects play a computerized ball tossing game where a random half of the subjects are led to believe they are being included in the game by other subjects and the other half are led to believe they are being excluded by other subjects. Change in mood (before vs. after the game) is measured by a questionnaire.

·         Subjects seeking treatment for depression are randomly assigned to either a new treatment technique or the current treatment technique. Change in score on a depression questionnaire before and after treatment is measured for the two groups.