A-Z Scales
Risk Attitude
Cognitive Ability

Numeracy - Expanded (11-item) Scale

Lipkus, I. M., Samsa, G., & Rimer, B. K. (2001). General performance on a Numeracy Scale among highly educated samples. Medical Decision Making, 21(1), 37-44. doi: 10.1177/0272989X0102100105
See also the original 3-item Numeracy measure by Schwartz et al. (1997) and the further expanded 15-item Numeracy measure by Peters et al. (2007).

Table of Contents


History of Use




The Numeracy measures were designed to assess numeracy, which is the ability to understand and use numeric information.
  • The 11-item measure adds 8 items to Schwartz et al.'s (1997) original measure.
  • Specifically, the expanded 11-item measure assesses understanding of risk and fractions as well as chance, proportions, and percentages.
  • See also the original Schwartz et al. (1997) 3-item measure and the expanded Peters et al. (2007) 15-item measure.

11 items using a mixed free-response and multiple-choice format


  • Medical decision making
  • Framing
  • Affect in decision making

Sample items

  • Which of the following numbers represents the biggest risk of getting a disease?
    • 1 in 100
    • 1 in 1000
    • 1 in 10
  • If the chance of getting a disease is 20 out of 100, this would be the same as having a __%
    chance of getting the disease.

History of Use:

Scale Uses:

  • Numeracy x framing: High numerate (identified by median split) were less susceptible to attribute framing, F(1,96) = 5.6, p < .05, η2 = .11. (Study 1)
  • Numeracy x framing: High numerate (median split) were less susceptible to formatting differences (percentage vs. frequency), F(1,42) = 4.0, p < .05, η2 = .42. (Study 2)
  • Numeracy: High numerate (median split) had more precise affect about choices, t(44) = -2.6, p < .01, d= .78. (Study 3)
  • Numeracy: High numerate (median split) rated superior no-loss bet lower than inferior loss bet, t(89) = 3.1, p <.01, whereas low numerate rated bets equally. [Conclusion: More numerate have clearer feelings about probability but sometimes pick worse gamble.] (Study 4)

Peters et al. (2006)


Lipkus, I. M., Samsa, G., & Rimer, B. K. (2001). General performance on a Numeracy Scale among highly educated samples. Medical Decision Making, 21(1), 37-44. doi: 10.1177/0272989X0102100105
Other Versions of Numeracy:
  • Peters, E., Dieckmann, N. F., Dixon, A., Slovic, P., Mertz, C. K., & Hibbard, J. H. (2007). Less is more in presenting quality information to consumers. Medical Care Research and Review, 64(2), 169-190. doi: 10.1177/10775587070640020301
Selected Uses:
  • Fagerlin, A., Zikmund-Fisher, B. J., Ubel, P. A., Jankovic, A., Derry, H. A., & Smith, D. M. (2007). Measuring numeracy without a math test: Development of the Subjective Numeracy Scale. Medical Decision Making, 27(5), 672-680. doi: 10.1177/0272989X07304449
  • Garcia-Retamero, R., & Galesic, M. (2009). Communicating treatment risk reduction to people with low numeracy skills: A cross-cultural comparison. American Journal of Public Health, 99(12), 2196-2202. doi: 10.2105/AJPH.2009.160234
  • Peters, E., Västfjäll, D., Slovic, P., Mertz, C. K., Mazzocco, K., & Dickert, S. (2006). Numeracy and decision making. Psychological Science, 17(5), 407-413. doi: 10.1111/j.1467-9280.2006.01720.x
  • Reyna, V. F., & Brainerd, C. J. (2008). Numeracy, ratio bias, and denominator neglect in judgments of risk and probability. Learning and Individual Differences, 18(1), 89-107. doi: 10.1016/j.lindif.2007.03.011
  • Reyna, V. F., Nelson, W. L., Han, P. K., & Dieckmann, N. F. (2009). How numeracy influences risk comprehension and medical decision making. Psychological Bulletin, 135(6), 943-973. doi: 10.1037/a0017327
  • Zikmund-Fisher, B. J., Smith, D. M., Ubel, P. A., & Fagerlin, A. (2007). Validation of the Subjective Numeracy Scale (SNS): Effects of low numeracy on comprehension of risk communications and utility elicitations. Medical Decision Making, 27(5), 663-671. doi: 10.1177/0272989X07303824