Is the design sound? Is sequence of photos a confound? If so, how would you control for its effects on the study? Is experimenter a confound? If so, how would you correct it in order to make the study methodologically sound? As part of a class research project, a group of three student-researchers (Ed, Ted, and Fred) decide to study the effects of physical attractiveness on ratings of success. Participants look at a set of five photos of highly attractive people, then five more photos of moderately attractive people. Finally, they see photos of five unattractive people. Previous research identified appropriate photos for each condition. To get a good cross-section of students, the researchers decide to test three types of students: psychology majors, business majors, and chemistry majors. By a random process, it is determined that the psychology majors will be tested by Ed, that Ted will test the business majors, and that Fred will test the chemistry majors