Examples: Hypothetical (fake) SAD Study
40 participants who reported suffering from SAD were randomly assigned to 2 groups that differed in light exposure. Group 1 (the “light” condition) sat under bright lights for 2 hours each morning. Group 2 (the “no-light” condition) did not. After 3 weeks, a survey measured how depressed each participant felt. The more questions a participant said “yes” to, the more depressed they were assumed to be. Those in the “light” condition were significantly less depressed.