The horizontal axis is based on a student's response to 24 multiple choice questions (2 points each), 8 free response questions worth 2 points each, 4 free response questions worth 4 points each, and 1 free response question worth 6 points, for a total of 86 points. The vertical axis will give the grade as reported in the student's records and report cards.
The curve used here adheres very closely to a cubic equation which is included in the graphic.
I cannot help but notice the "fast track" to level 3, which is the "passing" level for current students. The raw score takes a very large jump before getting to the "mastery" level 5.
Please take note that a student who can answer 8 multiple choice questions, and must guess at the other 16 of them, will tend to get 12 correct (the 8 plus one fourth of the remaining 16), for a total of 24 points. That student needs to get 1 point out of all the free response questions in order to pass. A student who knowledgeably answers 12 of the multiple choice questions, and guesses at the other 12, will tend to get 15 correct (the 12 plus one fourth of the other 12) for a total of 30 points, and at that point has already passed.
I will save my judgments for later, after I have had a chance to see the test itself.
Please take note that level 2 exists as a "safety net" for Special Ed. students, and its is a fairly narrow band. It seems the real goal in the scale is to get to level 3 quickly.