Accounting for cultural differences in caregiver research is now widely recognized. However, adapting instruments to assure reliable and valid data across cultures has been neglected, leading to concerns about information obtained in cross cultural research. This paper discusses instrumentation issues which influence the assessment of information in elderly women of Japanese descent who are caregivers to persons with dementia. Data from interviews in the Honolulu Aging and Caregiver Study focus on semantic, content, technical, criterion and conceptual equivalence.