[gavinlit]

Just imagine how easy it would be to grade maths papers of there was no partial credit. Just check that last couple of lines baby - mmm. Tempting, very tempting.
Maths lecturing & teaching is my game & I've got no problems with the partial credit idea. If someones sitting a paper, then the solutions are prewritten with certain marks going for each step of the process. No doubt you will lose marks if the final answer is not correct but I think it's fair that if you show knowledge of a certain process/method/technique, you get akcnlowledgement of that.

Some of the courses I've done have had open book exams & most of the others have a formula sheet provided. This allows you to set more realistic (demanding?) questions as you're not focussed on memory & recall. Most of my students have not found the open book exams any easier than the closed book ones. It all comes down to what you're trying to assess. If you're trying to assess 100% accuracy in working then you'd give a paper designed for that (ie no partial credit). If you're trying to assess understanding of concepts then that's what you're giving marks for.