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.
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. https://doi.org/10.1017/jdm.2023.17
NUM Items as Text:
All NUM items are available as text along with the item parameters on OSF: https://osf.io/u3qgz.
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).
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  or incorrect ).
Please direct any questions to firstname.lastname@example.org.
If you would prefer to use the Weller Scale (Weller et al. 2013), please click here.