AVERAGING VERSUS SUMMATION IN COMPOSITE RATINGS OF COMPLEX SOCIAL STIMULI

IN A STUDY OF THE RELATIONSHIP BETWEEN JUDGMENTS OF COMPOSITE STIMULI AND THE RATINGS OF COMPONENT PARTS, 108 SS EVALUATED PERSONS DESCRIBED BY 12 LETTER-OF-RECOMMENDATION EXCERPTS IN SETS OF 1, 2, OR 4. CONTRARY TO AN AVERAGING MODEL, EXCERPT SETS OF 2 OR 4 WERE RATED SIGNIFICANTLY HIGHER THAN SINGLE EXCERPTS. OSGOOD'S CONGRUITY MODEL WAS NOT SUPPORTED IN THAT COMPOSITE EXCERPTS WERE RATED MORE EXTREMELY THAN THE MOST EXTREME COMPONENT. HOWEVER, AN ADDITIVITY TEST BASED ON RATIONAL ZERO ESTIMATES DID NOT SUPPORT A SUMMATION MODEL OF COMPOSITE JUDGMENTS. IT IS PROPOSED THAT SET SIZE AFFECTS COMPOSITE JUDGMENTS INDEPENDENTLY OF THE EFFECTS OF STIMULUS COMBINATION. (17 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.