Multiple, correlated covariates associated with differential item functioning (DIF): Accounting for language DIF when...

Area of Science:

• Psychometrics
• Cognitive Aging Research
• Cross-Cultural Psychology

Background:

• Differential item functioning (DIF) is vital for detecting measurement bias in tests across diverse groups.
• Existing DIF methods may not adequately address correlated factors like education that differ between language groups.
• The analysis of multiple, correlated DIF factors remains an under-explored area.

Purpose of the Study:

• To assess DIF related to Spanish versus English language in an object naming test.
• To compare a new strategy, simultaneous accounting, for handling educational attainment differences across language groups with existing methods.
• To investigate how accounting for varying factors across language groups impacts DIF assessment.

Main Methods:

• Utilized data from 1,755 older adults (Spanish- and English-speaking).
• Administered a 44-item object naming test.
• Employed simultaneous accounting to analyze language- and education-related DIF concurrently.

Main Results:

• Simultaneous accounting revealed significant differences in object naming scores compared to other methods.
• These differences were particularly notable for Spanish speakers with at least 9 years of education.
• The strategy highlighted the importance of considering factors that co-vary with language.

Conclusions:

• Accounting for multiple, correlated factors like education is essential when assessing language-related DIF.
• Simultaneous accounting offers a valuable approach for cross-cultural cognitive studies.
• This methodology has broader applications in fields like health-related quality of life research.