Grading by assigning points to exercises For grading exams, I usually assign points to the exercises in such a way they sum to 100, and then I correct the exams by giving partial points based on such assignment.

Lately, I feel this is a poor choice: students which obviously don't get the topic sometimes get acceptable grades (because they sum some points for every exercise), while some students who understand the topic get bad grades (because they didn't do all the exercises, but some exercises they completed very well). Is there any resource (i.e. book or article) discussing this methodology of grading? What are the alternatives?

I think I'd like a grading methodology that analyses the whole of the exam not as the sum of the parts, but first I'd like to read about pros and cons.
If good students who understand the topic well are getting bad grades because they don't do all the problems, you should think very carefully about whether you've made the exam too long.

If this is what is happening (and I suspect it is), there is a very easy way to fix it: 


  Assign fewer problems.


Then you don't have to worry about coming up with a new kind of grading scheme that looks at the test as a whole, and which the students who get low exam scores will undoubtedly complain about.

If you designed the exam by looking at exams that professors had set in previous years, they probably also made the mistake of putting too many problems on the exam. It's a very easy mistake to make. I've heard the guideline that professors should be able to solve the problems on the exam in one third of the time that you give students, and I'm not at all sure that it shouldn't be less.