I work in a multilingual region, like many of us. My clients' websites are multilingual (often, there's a main language and sub-languages). When I perform a tree test on their structure, is it enough to test on main language or should I test for every language, since translation and cultural habits might come into play?
You need to test every language:
- Translation could be done incorrectly - missing items, typos, bad correspondence between original term and translation within common context.
- Cultural habits might come into play, as you mentioned.
- Trees might be different for each language.
- Translation may cause visual defects.
In general, multilingual website should be considered as many localized websites and common test procedure should apply for each of them.