That is a very good question, i face same issue every now and then. and it happened that i had an issue earlier this week with an oursourcer who my colleague referred and stated that he is very competent and reliable. unfortunately, that wasn't the case as the work came late and i had to chase him with calls and e-mails. and when the work finally received, it was utterly illogical and not solid. i spend the whole day going over the text and amending very trivial and unreasonable mistakes. very frustrating!