Cellphones and Exam Cheating

Another story of students’ use of cellphones to cheat has hit the news. The authorities in this case, the state of Mississippi, turned to technology for a solution, but not in the way you might think. They engaged a company that analyzes test results to find commonalities in mistakes that, according to the inventor, mark the students as cheaters. Apparently, cheating has declined considerably since the introduction of this tech-check (though how the state could know that through independent methods is unclear).

The old academic in me loathes cheating, so I would, at first blush, simply jam all cell phones in the exam room. But because I was a legal academic, the second blush informs me that cellphone jamming is a illegal in both the US and Canada. Section 4 of our Radiocommunication Act, R.S., 1985, c. R-2, forbids the operation of a “radio apparatus” other than a receiver, effectively. These prohibitions haven’t stopped the sale of various jamming devices, but would likely inhibit educational authorities from taking the direct technical route to stop this kind of cheating.

I am a little surprised, though, that authorities don’t use radio frequency (RF) shielding to keep signals out of exam rooms. It would seem that this is not a prohibited action (though telecommunications lawyers may tell me different). Essentially, you’d be creating a Faraday cage, a network of material with no openings or openings smaller than the target wavelengths, that keeps waves on its surface. (There’s a lovely classroom demonstration of a Faraday cage by MIT physics professor Walter Lewin on YouTube.) Various companies offer RF shielding materials and even paints.

In the spirit of scientific inquiry I tested the RF shielding power of aluminum foil, wrapping my iPhone in two layers (I cut too big a piece and had to fold it over) of the regular kitchen product. When I called my cellphone on my landline it went straight to message: no reception. Indeed, when I unwrapped my phone it complained that it had lost connection with the mother ship. My guess is that papering exam rooms with foil might be a good deal less expensive for Mississippi than paying for expert test testing. On the other hand, they might not be able to withstand the mocking.