I know, it sounds stupid. But, actually it really needs, while the work is poorly technology based, especially Programming jobs.
I had this experience, i had to scrape a large website having >100k entries. So, in the beginning, the crawling went smooth, but, when the website recognized large no of requests, it started to block the crawler. So, had to start crawling with less no of requests at timed intervals. But, the client couldnt seem to understand what is actually happening, he started to blame me. If he know something about websites and their security, it wouldnt have happen.
So, i do prefer some tests for the clients, to make sure that they know some basics about the job they have posted.
If i was ranting, i am really sorry.