A wide variety of instruments are available to assess numeracy. However, researchers rarely provide information regarding the specific numeracy aspects assessed and the complexity of the items used. Instruments that differ in content may produce inconsistent patterns of correlation, thereby complicating the interpretation and comparison of findings across studies. This paper addresses this issue through answering the research question: What are the content characteristics of the numeracy instruments used in the context of research on consumers’ f inancial difficulties? In a scoping literature review, we identified nine numeracy instruments used in the context of research on consumers’ financial difficulties (e.g. over indebtedness). We examined the specific numeracy aspects they assess and the complexity of their items. Items were coded for numeracy aspects, using the Common European Numeracy Framework (CENF). For complexity the PIAAC Numeracy Task Complexity Schema was used. Results reveal both similarities and differences across the instruments. A similarity is that all instruments assess only a limited aspect of numeracy. A key difference is the variation in item complexity. The findings facilitate comparisons across studies and assist researchers in selecting or designing suitable numeracy instruments. In conclusion, the study highlights notable differences between numeracy assessment instruments, underscoring the need for caution when interpreting and comparing their results. Further, this article provides some practical guidelines for researchers seeking to assess numeracy.
