Define direct translation, back translation, and parallel translation

What will be an ideal response?

Direct translation involves a bilingual translator who translates the questionnaire directly from a base language to the respondent's language. In back translation, the questionnaire is translated from the base language by a bilingual speaker whose native language is the language into which the questionnaire is being translated. This version is then retranslated back into the original language by a bilingual whose native language is the initial or base language. Translation errors can then be identified. Several repeat translations and back translations may be necessary to develop equivalent questionnaires, and this process can be cumbersome and time consuming. An alternative procedure is parallel translation. A committee of translators, each of whom is fluent in at least two of the languages in which the questionnaire will be administered, discusses alternative versions of the questionnaire and makes modifications until consensus is reached. In countries where several languages are spoken, the questionnaire should be translated into the language of each respondent subgroup. It is important that any nonverbal stimuli (pictures and advertisements) also be translated using similar procedures.