So I just saw the "60 Minutes" segment on professional cheaters of the SAT test.
These smart students make fake IDs to impersonate their clients and get them high scores.
Granted there were only around 150 confirmed cases out of 3,000,000 tests taken. So even if the confirmed cheats are only 5% of the actual number then that would indicate a still a pretty successful 99.9% fair/non-cheat rate.
Nevertheless, impersonation is a problem.
Here's a solution...
1) Equip all testing locations with a digital camera (or require them to use their own) and ensure each student is photographed when he/she signs-in. (Possibly also scan-in his/her ID for extra security).
2) Upload all photos to the testing company's website/database.
3) Use "facial recognition system" to automatically compare potential matches. Investigate flagged-potential matches.
4) Post the test-takers' photos with their scores when the colleges look them up.
* Note: This has the added benefit of discouraging would-be cheaters because their photos will exist on the database forever. Consequently, if a cheating ring is ever exposed the evidence will exist to go back and expose ALL involved (test takers & clients).
This should also be enacted for online courses (e.g. MITx) so that final exams are conducted by objective, secure proctoring services.
BTW - I am interest in this because of my related ideas (including: "testing/certification" is or will likely be more important than how/where you learned a subject AND ALSO see my idea about Graduation Authentication Links).
