Frames of Reference in Quantity Estimations by Groups and Individuals

The superiority of group performance over performance of the average individual is relatively greater on world knowledge tasks than on quantity estimation tasks. Previous research on quantity estimations has involved judgments without an explicit frame of reference. We propose that a frame of reference converts a quantity estimation into a world knowledge inference by embedding the estimation in a larger cognitive structure. Individuals first estimated 30 pairs of quantities, such as the length of the Ohio River and the length of the Arkansas River, given either 2 statements as a frame of reference (the Mississippi River is 2340 miles long; the Colorado River is 1450 miles long), 1 of these statements as a frame of reference, or no frame of reference. Then they made the same 30 pairs of estimations again as 3-person groups or as individuals under the same frame-of-reference conditions. As predicted, group estimations were more accurate than individual estimations, both group and individual estimations were more accurate with either a 2-statement or a 1-statement frame of reference than without a frame of reference, and the frame of reference improved group estimations relatively more than individual estimations. Copyright 1999 Academic Press.