Table 1 Definition of aspects of equivalence according to Hardman (1998) [26], extracted from Saub et al. (2007) [35]
Equivalence | Definition |
|---|---|
Conceptual | Ways in which different populations conceptualize health and quality of life (QoL) and the values they place on different domains of health and QoL. |
Item | Concerns the way in which domains are sampled. Item equivalence exists when items estimate the same parameters on the latent trait being measured and when they are equally relevant and acceptable in both cultures. |
Semantic | Concerned with the transfer of meaning across languages. |
Operational | Refers to the possibility of using a similar questionnaire format, instructions, mode of administration, and measurement method (response format). |
Measurement | Ensuring that different language versions of the same instrument achieve acceptable levels in terms of their psychometric properties – reliability, responsiveness, and validity. |
Functional | The extent to which an instrument does what it is supposed to do equally well in two or more cultures. |