For his undergraduate capstone project, Jorge wants to determine if memory recall differs based on the color of the testing room. He plans to study a bright color (e.g., red), an earth tone (e.g., forest green), and a neutral color (off-white). Participants are randomly assigned to groups and there are 30 participants per group. Jorge is concerned that some participants might be assigned to a room that matches their color preference. For example, a person whose favorite color is red might be assigned to the red room. Jorge's advisor probably would reply that:
the bright color group should be eliminated.
color preference probably will have no effect on the results.
color preference could affect the results, but it would affect all groups equally.
the experimental design is confounded and is in need of revision.
