@hawkb @SusanNiemeyer -
Yes that is definitely a workaround. Of course you have to create 2 rubrics for the 2 assignments which is a lot of work. Perfectly fine, and I thought the same thing yesterday when I thought about writing up what I have below. However yesterday I could not think of the correct procedure for my procedure below for whatever reason. Then this morning it came to me how to do it correctly.
If it were me, I would do the following (it would have to be explained to the student what is happening with their grade). I would use the same rubric for both groups of students. I would add a line into the rubric at the bottom that has the criteria statement of "for adjusting students grade based on answers not covered by the criteria above". For this criteria you just have 2 options both worth 0 points (I do this all the time in my programming class because students are great at doing wrong things not covered by the criteria). Then grade all the regular students and never use the last criteria.
for the special needs student, grade their work on all the criteria applicable to them. Determine their grade. then you can use the last criteria for fudge points to adjust the overall score for the correct percentage.
For example. assignment is worth 100 points, and the excused criteria is 10 points. So if the special needs student scores a 90/90 (get all their parts correct), then you just add +10 in the adjustment box and put in a comment as to why that is there.
if they get an 80/90 = 88.89%, then you can add 8.89 into the score box and once again provide an explanation. This gives the student an 88.89/100 which is the correct percentage.
The above is a little bit of work, but less than creating 2 assignments and 2 rubrics.
And for anyone wanting to know, you can add negative points in the adjustment box score in a rubric as well (I do that all the time)