ipipbig-fivefacetsauthoring
Big Five facet-level items inspired by public-domain IPIP patterns
How we author 1-5 Likert items per facet, route by id prefix to trait aggregates, and what the BFI-2-R Rasch validation says about facet-level scoring.
Citation
PsiMatch Product & Research Team (2026). PsiMatch Methodology — DOI 10.1007/s12144-025-07584-7
View source4 min · Updated 2026-08-27
Educational context only, not a diagnosis or clinical assessment. Product-authored items are labeled where validated instruments do not apply.
§ 01 — Findings
What the study found
- Every Big Five item carries a facet namespace prefix (opn-, con-, ext-, agr-, neu-) and three facets per trait, mirroring the BFI-2-R structure.
- Facet-level scores satisfy Rasch model assumptions (monotonicity, local independence, unidimensionality, no DIF) per the 2025 Italian validation study (N=5362).
- Trait-level confidence is the stronger signal to surface to users; facet rankings of individuals are thinner evidence (low PSR for some facets).
§ 02 — Encoding
How we encode it
- Why trait scores carry more weight in compatibility math, even when facet data is richer.
- Why we lean into facet-level routing rather than collapsing to trait-level blobs.