Validating a survey instrument
Translation is not a mechanical work and should not be done on word to word bases across languages.
It is important to understand the local context, specific issues and cultural meanings which language carries.
Back translation helps in evaluating the quality of the translation.
The source language is translated in another language and again translated back into the source language.
If a new questionnaire is to be developed, it should be pilot tested and validated in order to evaluate if it is measuring what it supposed to measure and is it doing it reliably.
Wording of questions is very critical and should take into consideration; appropriateness of the content, level of sophistication of language, type and form, sequence and how is data sought from the respondents.
During questionnaire development its mode of administration should be kept in mind, whether it will be self-administered or interview based and its design and flow should be planned accordingly. The language of questionnaires should be at the level of understanding of the participants.
It is essential to word the questions in a way that they can easily be understood by participant and should be according to their educational level and culture.
Composing of a questionnaire is always much more complex than expected and great attention is required to its flow, format and length.
Unstructured format may be used at clinical setting however structured questionnaire is preferred for epidemiological studies as same data from all respondents need to be analyzed and measured.
Open-ended questions allow respondents to answer them in any way they want.
Making an individual question is a tedious task and validating this questionnaire is another challenge which at times is over looked.
Consideration should be given accordingly on whether the questionnaire will measure quantitative or qualitative data, and what would be its mode of administration.