Raw marks are the actual marks that you get in the exam, scale mark is where they put it to the most appropriate grade. For example. bob scored 78 in his economics exam in 2003 and got an A*, in 2004, jimbob scored 78 in his economics exam as well, but because jimbobs exam was slightly easier he only got an A. so 78 was the raw mark, and the boundary for the grades they got are scaled.