Framing of imprecise quantities: When are lower interval bounds preferred to upper bounds?

Abstract

Imprecisely known quantities (e.g., predictions) are often described in approximate terms as ''more than X'' or "less than Y" (e.g., "Ann will earn more than $50 000" or "less than $60000"). Such phrases carry both quantitative and qualitative (pragmatic) information. Three studies are reported showing that lower limit estimates (more than, over, minimum) are generally more frequent, and considered more appropriate than upper limit estimates (less than, under, maximum) over a wide range of contexts. This is partly due to scalar properties of the number system, where lower numbers are attained before, and included in higher numbers, but not vice versa. As a result, upper limit statements are perceived as negations, and carry more specific information about the speaker's communicative concerns. Upper limit statements are preferred with amounts or quantities that can be perceived as small, whereas lower limit statements can be used both to indicate large quantities and as a default. Copyright © 2009 John Wiley & Sons, Ltd.