When I give my Geometry for Teachers students an exam, I always give a take-home portion that contains what I refer to as ‘teacher-type’ problems. These are problems that they need to be able to do when they are a teacher. Typically, they involve writing directions, grading a test question, creating a rubric, writing a test question, or evaluating curriculum. For their first exam, I gave them the following problem.

Two of your student’s solutions to finding the radius of the inscribed circle are below. One of the solutions is correct and one is incorrect.

a) Write up a detailed solution and rubric to finding the radius of the inscribed circle.

b) Grade both students' solution according to your rubric.

c) Which student has the correct solution?

I am going to focus this post on the rubric and how they graded the students' solutions. I was very impressed with their rubrics and wanted to share them.

Natalie's solution

Logan's solution

Some items that we discussed about their rubrics when I returned the
exam:

- Point values on the question ranged from 5 points to 15 points. What is the best way to determine the point value of a test question?
- Was notation specifically listed in the rubric? Some students listed it and some didn’t. One of the students that didn’t list notation felt that she could take off a point for notation under the justification portion of her rubric.
- What is the best way to make a rubric? We talked about how you need to make a key for a question before you could really determine the number of points that you should allot to that question?

Student A

Student B

Student C