“…The implicit assumption of numerical equivalence is prevalent in studies of psychophysics (e.g., Gescheider, 1988;Marks, 1974;Marks & Algom, 1998;Stevens, 1956Stevens, , 1986, risk estimation (e.g., D. J. Cohen & Bruce, 1997;Gladis, Michela, Walter, & Vaughan, 1992;Hansen, Hahn, & Wolkenstein, 1990;Mickler, 1993;van der Velde, van der Plight, & Hooykaas, 1994), mathematics (e.g., Ashcroft, 1992;Ashcroft & Kirk, 2001;Campbell & Xue, 2001), reasoning (e.g., Kahneman & Tversky, 1972;Tversky & Kahneman, 1974;Wanke, Schwarz, & Bless, 1995), and probability estimation (e.g., Begg, 1974;Brooke & MacRae, 1977;Hollands & Dyre, 2000;Shuford, 1961;Spence, 1990;Teigen, 1973;Tversky & Fox, 1995;Varey, Mellers, & Birnbaum, 1990), to name just a few. The assumption of numerical equivalence, however, should not be made lightly because people's interpretation of numbers likely affects the data they produce, and thus the conclusions that researchers draw.…”