Once you’ve sorted out which kind of interpreter you need, here’s how to choose the right person and work effectively with her. If you can, allow up to a month to do the following:
Test your chemistry: Some interpreters bring energy to the presentation; others can drain you. Spend time speaking with yours before you hire them. If you have time to interview a few candidates, that’s all the better. You’ll know someone’s a good fit if she makes you laugh, for example, or calms you down. The interpreter shouldn’t agitate you in any way—public speaking in a different culture is hard enough as it is. You should trust that she values your material and will represent it well.
Call in reinforcements: If you can’t find an excellent interpreter who’s also a subject matter expert (it’s a rare breed), use the professional interpreter as your primary source of translation—but also enlist a subject matter expert who speaks both languages to help out. That way you’ll have someone who can correct the interpreter if she makes content mistakes here and there, in real time, or who can simply step in at a point where the material gets highly specialized or technical.