Code Litmus test

A few weeks ago an email was going around about how you could diagnose a stroke without any medical training just by answering three simple questions and get the person to the doctor in time for treatment.

I spoke to my colleague Andreas Brink about using that idea in another context, a little less serious one such as code. He said immediately that only one question is needed and that would take people without much development experience a long way. That question is "Is there any duplication?" Lots of other problems boil down to that simple question. Iím sure we can get Andreas to expand on this further...
:-)

Another similar question I've often heard is "Is that testable?" (but that requires experience in test automation). Do you have another favorite?