- SIGNING: put your initials, so that people know whom to contact,
  if they want a regrade

- EXPLANATIONS: no need to give the solution - we'll publish them -
  but clearly mark the penalty/score, and mark the reason of your score
  * put 'check-marks', whenever the answer is correct.
  * use notation like '2/3', when they get 2 out of max 3 points

- CONSISTENCY: write down the list of rules and penalties,
   for partial credit, for consistency.
   Eg., "missed the referential IC from 'gym' to 'customer': [-1]"

AFTER all questions are graded

- do the summations TWICE (two different people - 
  both of them sign their initials)

- SORT questions by student last name