Andy is studying the effects of caffeine and alcohol on cognitive performance. He randomly assigns participants to one of six conditions: caffeine/low alcohol; no caffeine/low alcohol; caffeine/high alcohol; no caffeine/high alcohol; caffeine/no alcohol; no caffeine/no alcohol. This is best described as a ______.
1 × 2 between-subjects factorial design
2 × 2 between-subjects factorial design
2 × 3 between-subjects factorial design
2 × 2 × 2 between-subjects factorial design
