This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
It is a common practise at my Uni, its where when you get an answer wrong, marks are subtracted, so in theory you can come out with a negative score its designed to discourage guessing at multiply choice exams.
To the best of my knowledge the SCJP dos NOT use negative marking!