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NUMERACY

Our grasp of numbers is one of humankind's most distinctive and important traits. It is pivotal to our exceptional ability to control the world around us as we make short-term choices and forecast far into the future. But very smart people can struggle with numbers in ways that have negative consequences for their decision making. We study how numeric competencies equip people with vital tools that allow them to take charge of their life. The more numerate enjoy superior health, wealth, and employment outcomes, while the innumerate remain more vulnerable.

NUMERACY SCALES

Numeric Understanding Measures (NUM) for Short-Form Assessments of Numeracy

The Numeric Understanding Measures (NUM) were developed using Item Response Theory to create brief measures of numeracy without sacrificing the scope of the construct. The Adaptive Numeric Understanding Measure (A-NUM) and Four-Item Numeric Understanding Measure (4-NUM) each require participants to complete four numeracy items. The A-NUM consists of 13 unique items and will present different questions depending on the participant's performance on the assessment. The A-NUM can categorize participants into nine ability levels or estimate the latent ability as a z-score (16 possible scores). The initial item of the A-NUM may also be used as a single-item measure (1-NUM). The 4-NUM items are the same for all participants (none of these items are part of the A-NUM). To protect the scale’s usefulness to researchers, please do not post any of the items online or in publications. You can point instead to the publication below. 

Manuscript

Silverstein, M., Bjälkebring, P., Shoots-Reinhard, B., & Peters, E. (2023). The numeric understanding measures: Developing and validating adaptive and nonadaptive numeracy scales. Judgment and Decision Making, 18, E19. 

NUM Items as Text:

All NUM items are available as text along with the item parameters on OSF: https://osf.io/zunrj.

Please note that the correct answers are not provided in this file to avoid the publication of these answers online and protect the usefulness of these measures to researchers. 

Measures for Use in Qualtrics (With Automatic Scoring): 

A Qualtrics file (Qualtrics Survey Format) for the A-NUM can be downloaded from OSF: https://osf.io/frq2n.

  • This file may be uploaded as a new project in Qualtrics. Please note that this file contains embedded data to score participants. These embedded data will appear in your dataset as NUMScore (the preferred scoring method; participants are categorized into nine ability levels; range: 1-9), NUMZ (participants are scored using expected a posteriori estimates; range: z = -2.57 and z = 2.21), and NUMRank (the percentile rank based on the expected a posteriori estimates). The initial item of this adaptive measure is the same item used in the 1-NUM  

 

A Qualtrics file (Qualtrics Survey Format) for the 4-NUM can be downloaded from OSF: https://osf.io/4tk2f.

  • This file may be uploaded as a new project in Qualtrics. Please note that this file contains embedded data to score participants. These embedded data will appear in your dataset for each individual item (e.g., 4_NUM_1_Scored; 0 for incorrect and 1 for correct) and for the sum score across items (i.e., 4_NUM; range: 0-4).  

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A Qualtrics file (Qualtrics Survey Format) for the 1-NUM (the initial item of the A-NUM) can be downloaded from OSF: https://osf.io/dsxjb.

  • This file may be uploaded as a new project in Qualtrics. Please note that this file contains an embedded datum to score participants. This embedded datum will appear in your dataset as 1_NUM_Scored (whether the participant was correct [1] or incorrect [0]).  

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Please direct any questions to caide@uoregon.edu.

Weller Numeracy Scale

Manuscript

Weller, J., Dieckmann, N. F., Tusler, M., Mertz, C. K., Burns, W., & Peters, E. (2013). Development and testing of an abbreviated numeracy scale: A Rasch Analysis approach. Journal of Behavioral Decision Making, 26 (2),198-212. 

Scale Materials

Materials for scale items and a corresponding Qualtrics file can be found on OSF: https://osf.io/n6a8s/.

Scale Update (02/2016)

Please note that the last two questions, 7. and 8., are well known on Mechanical Turk. Items from Toplak, West, and Stanovich (2014) have been used as substitutes for those questions when administering the scale on MTurk.

Scale Update (06/2014)

Please note that we adjusted the list of accepted answers for most of the items. Many of these newly accepted answers include alternative formats to previously accepted answers. Further commentary is included in the additional material.​

Scale Update (02/2013)

Please note that we adjusted the mammogram item on the numeracy scale to reduce guessing and improve the scale further (i.e., before the answer to the item was 1/2). There is evidence suggesting that when people do not know the answer to a probability judgment their answer is 1/2 or 50% (Fischhoff & Bruine de Bruin, 1999).

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Please direct any questions to caide@uoregon.edu.

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