Before you just place any old photo into an online course or informational website, it's a good idea to think about whether a realistic graphic is required. And if so, how much realism will be most effective? By realism, I mean how well a graphic appears to be a successful copy of its referent. A common assumption is that more realism corresponds to greater comprehension. But this assumption is not based on fact. Surprisingly, a lot of research points to the opposite; realistic graphics are frequently not as effective as those with reduced realism.