Factor structure and psychometric properties of the French Versions of the Big Five Inventory-2 Short (BFI-2-S) and...

A growing body of research has recently highlighted that informant-report is a unique and too often neglected source of personality information. Several personality questionnaires have a form that can be filled out by informants, including the second version of the Big Five inventory (BFI-2), which uses 60 items to assess five major personality dimensions or domains and 15 facets. However, researchers sometimes need shorter questionnaires. The objective of this study was to verify the psychometric properties of the two short forms of the BFI-2 informant-report.

We asked 1445 students of psychology and sports science and technology to describe a person they know well, and we obtained the complete description of 1380 people. We used exploratory structural equation models to analyze the factor structure of the two sets of items making up the 30-item BFI-2-S, which provides the assessment of the "Big Five" domains and 15 facets (6 items per domain, 2 items per facet), and the 15-item BFI-2-XS which only provides the assessment of the Big Five. We assessed the psychometric properties of the scales measuring the big five domains using conventional indices, and the psychometric properties of the BFI-2-S facets based on the significance and magnitude of the observed and residual correlations between the two items of which they are composed.

The analyses showed excellent fits to the data of the five-factor models. For both questionnaires, almost all items had a high loading on the expected factor, and the cross-loadings overall were small. The correlations between the factors were also small, which indicated discriminant validity. The correlations of the short form scales with the full BFI-2 scales were very large, including the facet scales of the BFI-2-S, indicating excellent concurrent validity. Multigroup analyses suggested differential functioning of certain items, but the magnitude of this bias was small to negligible and insufficient to explain differences according to the gender and age of the people described.

The two short forms of the informant-report BFI-2 presented the expected factorial structure and had satisfactory psychometric properties. When the informants were students, they provided reliable and valid descriptions of older people, engaged in family, professional and social life and who often were not available to participate in personality studies. However, it is unknown whether this conclusion can generalize to less educated informants.

The 30-item BFI-2-S and the 15-item BFI-2-XS informant-report forms provide a valid substitute for the full BFI-2 when external circumstances limit the time available for data collection, provided that it is possible to call on reliable informants.