I guess that depends on the industry the intern is being used. In photography, an intern typically does a lot of the manual labor like loading/unloading gear from the truck, setting up ligts,stands,tripods,etc. As the intern continues to do this work, they should be able to start learning when/where/why certain gear is being used and where to put initial settings. There is no "week to do something I could do in an afternoon" situation. It all has to be done right then and there. This allows the photographer to spend more time working with the subject/talent/producers/client/etc. After being an intern for long enough, that intern should be able to go off and be a decent assistant if not photographer on their own right.