Being a design instructor has many challenges when trying to assess a student's progress the class. Traditional tests are not applicable to this type of learning experience as it is all projects based that have be assessed on both quantitative and qualitative values.
Quantitative values are easier to assess such as completion of requirements, clarity of presentation, neatness of graphics, etc..
Qualitative values are harder to assess as this can be seen as subjective judgement of a student's creative expression in their project.
I have have found that producing a graphic matrix of all theses criteria and using a scale of 1 to 5 (low to high) in grading each category can help a student visually relate to the values to how the project was evaluated.