Grading Systems Part 2 - Weighting

From my first year of teaching I have always placed weights on the different categories of graded work in my classroom. For example this year, though not by choice, my weights looked like this:

70% - Tests

20% - Quizzes

10% - Everything else

I was not a fan of this weighting system because I thought it devalued responsibility (we also allowed retests). But I believe a system that weights the grade categories is the most appropriate. As I was going through school I was always amazed at how "fly by the seat of the their pants" teachers were with their grading system. What I mean is they seemed to randomly assign points and then they would add up the points and divide by the total to see what the grade was. The problem with this method is that from grading period to grading period the grade represents something different. Also it is much more likely that one category will dominate the grade. Often this leads to homework being overvalued, which I think is a problem.

Here is a few things I believe:

• The majority of the grade should be knowledge/skill based. The grade should be an accurate representation of what a student knows.
• Homework and responsibility should play a minor roll in a students grade. The grade should also represent a student's probability of success at higher levels. Hard work and responsibility are key to success(especially in math classes) as students reach harder classes.
• Behavior should play no role in a student's grade.

So the question is, what is the appropriate percentages?