Skip to main content

Are they equivalent? An examination of task variants of approximate number comparison


Nonverbal numerical ability supports individuals’ numerical information processing in everyday life and is also correlated with their learning of mathematics. This ability is typically measured with an approximate number comparison paradigm, in which participants are presented with two sets of objects and instructed to choose the numerically larger set. This paradigm has multiple task variants, where the two sets are presented in different ways (e.g., two sets are presented either simultaneously or sequentially, or two sets are presented either intermixed or separately). Despite the fact that different task variants have often been used interchangeably, it remains unclear whether these variants measure the same aspects of nonverbal numerical ability. Using a latent variable modeling approach with 270 participants (Mage = 20.75 years, SDage = 2.03, 94 males), this study examined the degree to which three commonly used task variants tapped into the same construct. The results showed that a bi-factor model corresponding to the hypothesis that task variants had both commonalities and uniqueness was a better fit for the data than a single-factor model, corresponding to the hypothesis that task variants were construct equivalent. These findings suggested that task variants of approximate number comparison did not measure the same construct and cannot be used interchangeably. This study also quantified the extent to which general cognitive abilities were involved in both common and unique parts of these task variants.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3

Data availability

Data and analysis codes are available from the corresponding author upon request.


Download references

Open practices statements

The data and materials for this study are available at the Open Science Framework (DOI 10.17605/OSF.IO/5FBKP), and this study was not preregistered.


This work was funded by the National Natural Science Foundation of China (32171070), Guangdong Basic and Applied Basic Research Foundation (2021A1515010738), and Guangdong Philosophy and Social Sciences Foundation grants (GD19CXL04) to Y.M.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Yi Mou.

Ethics declarations

Conflict of interest

The authors declare no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This manuscript has not been sent to Behavior Research Methods for peer review before, nor is it under consideration for publication elsewhere.

This study was approved by the Institutional Review Board of the Department of Psychology at Sun Yat-sen University.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mou, Y., Xiao, H., Zhang, B. et al. Are they equivalent? An examination of task variants of approximate number comparison. Behav Res (2023).

Download citation

  • Accepted:

  • Published:

  • DOI: