Developing instruments for cross-cultural psychiatric research.

The growth of cross-cultural psychiatry is now occurring at a time when psychiatry in general is emphasizing diagnostic clarity and the use of quantifiable and reliable methods of collecting clinical and research data. It is now imperative that cross-cultural psychiatry also examine its methods for developing instruments for use in cross-cultural research. This paper outlines a method for developing instruments designed in one culture for use in a second, and particular attention is given to cross-cultural validity or equivalence. Five types of equivalence are enumerated and defined: content, semantic, technical, criterion, and conceptual equivalence. These concepts are illustrated by examples from the authors' experience in research on internal migrants in Peru.