There's also the issue, isn't there that it seems kind of unlikely that the signal coming off the back of a router would cause the effects claimed...? I'm sure kids do worse experiments in school science classes all the time demonstrating well established effects. The problem is applying the same methodology to an effect that may be hard to detect/not exist/be muddled up in other effects.
By the way, is there any indication of how some school science project made it into the newspapers? Also, did the kids really notice that they couldn't pay attention after sleeping next to their phones? I've never noticed that and I sleep near/next to my phone off and on. Is this a class of electrosensitives? If I was their teacher, I'd wonder whether it was because they wouldn't put their phones down to go to sleep.