Here are some useful resources

http://www.naopindia.org/sites/default/files/ITC%2520Guidelines%2520-%2520Translating%2520and%2520Adapting%2520Tests%2520-%2520v2%25203.pdf

My recommendation would be back-translation and revalidation with the translated version using the population you are developing it for. Cultural or language differences could have substantial implications for the factor structure, validity and reliability

http://www.psyktestbarn.no/cms/ptb_mm.nsf/lupgraphics/ITC%2520guidelines.pdf/%24file/ITC%2520guidelines.pdf

http://www.who.int/substance_abuse/research_tools/translation/en/

I agree with Prof Stupple's recommendation.

Forward-backward method is the most recommended by expert to cross-cultural adaptation of instruments. In addition I recommend you to follow the COSMIN (consensus for instruments validation) checklist. Maybe this can be useful:

-http://www.who.int/substance_abuse/research_tools/translation/en/

-Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Recommendations for the cross-cultural adaptation of health status measures. Rosemont, IL: American Academy of Orthopedic Surgeons; 2002.

-http://www.cosmin.nl/

Thank you sirs for your answers and kind guidance. 

Agree, Leonhard,

Measurement invariance, not mere structural invariance, is the crucial evidence. 

Trevor

You have been provided with sound advice by others. I can only reinforce their views saying that yes, revalidation is necessary.

Best wishes with your study,

John

Get a subject matter expert to check the translation as well as going through the forward-backward translation method. If possible, get a subject matter expert who can speak both languages to ensure that it means the same thing in both languages - sometimes the translations can work perfectly in terms of forward-backward translations but actually mean something slightly different in each language. The translation will need to be analysed for reliability, validity and possibly re-normed as validation studies rarely transfer across languages.

The short answer to your question is yes, it does need to be re-validated.  This is because validation and reliability analyses are for a specific population and when you are translating a protocol or instrument, it is clearly for use with a different population.  Also, the other people who answered this are entirely correct about translating the instrument and then having someone else translate it back to check the translation.  A final caution is that any protocol or measurement tool used clinically is also based on the culture of the group being assessed.  Thus, most tools must be adapted rather than just translated.  This is one of the main reasons you need to re-validate with the new population.

Really grateful for everyone who took time to respond. Your answers are very helpful.

Hi Hussien,

You need to carry out an adaptation of the test. As several colleagues have already mentioned, it is a deeper process than the translation in which the researcher must provide both the evidence of the semantic equivalence of the items and the measurement invariance.

You can find the standards recommended by the International Test Commission to make a successful adaptation of tests in different cultures in this link. https://www.intestcom.org/files/guideline_test_adaptation.pdf  (ITC Guidelines for Translating and Adapting Tests), and specific aspects of procedures in this article by Ronald Hambleton: 

https://www.researchgate.net/publication/232562063_Translating_Tests_Some_Practical_Guidelines

Best wishes with your investigation

Erika

Article Translating Tests: Some Practical Guidelines