The Subjective Numeracy Scale (SNS) is a self-report measure of perceived ability to perform various mathematical tasks and preferences for the use of numerical versus prose information. The SNS has been validated against objective numeracy measures and found to predict comprehension of risk communications and ability to complete utility elicitations.
The 8-item scale contains no mathematics questions and has no correct or incorrect answers. Instead, it consists of 4 questions asking respondents to assess their numerical ability in different contexts and 4 questions asking them to state their preferences for the presentation of numerical and probabilistic information. The SNS is both reliable and highly correlated with the Lipkus, Samsa & Rimer (2001) numeracy measure, and it has been validated in both risk communication and utility elicitation domains.
For a PDF version of this document and the SNS instrument, click here: Subjective Numeracy Scale PDF.
Please contact Angie Fagerlin for versions in Dutch, Japanese, Norwegian, Portuguese, and Spanish.
For each of the following questions, please check the box that best reflects your answer:
- How good are you at working with fractions? (Not at all good – Extremely good)
- How good are you at working with percentages? (Not at all good – Extremely good)
- How good are you at calculating a 15% tip? (Not at all good – Extremely good)
- How good are you at figuring out how much a shirt will cost if it is 25% off? (Not at all good – Extremely good)
- When reading the newspaper, how helpful do you find tables and graphs that are parts of a story? (Not at all helpful – Extremely helpful)
- When people tell you the chance of something happening, do you prefer that they use words ("it rarely happens") or numbers ("there's a 1% chance")? (Always prefer words – Always prefer numbers)
- When you hear a weather forecast, do you prefer predictions using percentages (e.g., “there will be a 20% chance of rain today”) or predictions using only words (e.g., “there is a small chance of rain today”)? (Always prefer percentages – Always prefer words)
- How often do you find numerical information to be useful? (Never – Very often)
All questions use 6-point Likert-type scales with endpoints as marked. Response values increase left to right (1-6). Scoring is based on these values, except Question 7 is reverse coded (6-1) for consistency.
- SNS: Average rating across all 8 questions (w/ Q7 reverse coded)
- SNS ability subscale: Average rating on Questions 1-4
- SNS preference subscale: Average rating on Questions 5-8 (w/ Q7 reverse coded)
To cite the scale, please use the following reference:
Fagerlin, A., Zikmund-Fisher, B.J., Ubel, P.A., Jankovic, A., Derry, H.A., & Smith, D.M. Measuring numeracy without a math test: Development of the Subjective Numeracy Scale (SNS). Medical Decision Making, 2007: 27: 672-680.
In any discussions about the validation of the scale, please use the following reference:
Zikmund-Fisher, B.J., Smith, D.M., Ubel, P.A., Fagerlin, A. Validation of the subjective numeracy scale (SNS): Effects of low numeracy on comprehension of risk communications and utility elicitations. Medical Decision Making, 2007: 27: 663-671.