I am currently a teacher of the visually impaired at a public high school. I work in a SELPA classroom and have about 12 students on my caseload. I support my students in most every subject and I am their primary teacher for mathematics.
I have taught the Geometry unit on right triangles to some of them, but for the unit plan from week two, I totally revamped the entire process. I practiced the pre-assessment from Day 1 with five of my students. Two of them had already taken geometry, two of them are currently in a geometry class, and one of them has not yet taken geometry and is in an algebra 1 class.
Since my students are blind, I had to prep them for the Wizard of Oz clip that I planned to start the unit with. The clip is mostly verbal, so not much was lost on them. The part where the scarecrow "gets his brain" and states the Pythagorean Theorem was clear. Students seemed engaged by the movie clip.
I presented the students with two basic Pythagorean Theorem problems. Three of the students are blind and two have low vision, so I had Braille graphics and large print versions of the problems. The students were not able to complete the problems on 3x5 cards, so I have them complete the problems as normal. I also listed the Pythagorean Theorem formula above the two problems for the ones that had never been exposed to it before.
I collected the answers and was prepared to talk about me "Favorite No's" with the group. The problem was that only one student got an incorrect answer. As a group, we talked about that problem and the mistake that was made. The student made the same mistake with both problems. The formula is leg^2+leg^2=hypotenuse^2. In each instance, the student mixed up a leg with a hypotenuse and got the wrong answer. The other students quickly noticed this and talked about the correction.
I also talked with all the students about always making what I call a "does that make sense" check. When you have a number answer, it should "make sense" when compared to the numbers you started with. In both instances, the incorrect answer was a large amount off of the other two numbers. This would be a signal that something in the calculation was incorrect.
There is not necessarily a rubric for this pre-assessment. It is an informal assessment that can identify specific students that need help with a certain topic. It can also gauge the overall understanding of the class as a whole. The teacher must be able to think quickly on his or her feet to find an incorrect answer that can be talked about that will benefit the entire class and not make a certain student feel inadequate or dumb. The answers are not only informal assessment. The teacher should use the class discussion to assess the class's understanding as well.
The pre-assessment did it's job, but there were some problems in this field test. First, since the group was small, it was obvious in the discussion who had contributed the one incorrect answer. Fortunately this was a group of good friends, so there was no discomfort or embarrassment. In another setting, if it was obvious who made the incorrect answer, it may be disheartening to the student who contributed it. There are two caveats to this problem. In a regular class size of 30 or more, it would not be obvious and there would likely be more incorrect answers to choose from. Also, over the course of a year in a class, the teacher can create an atmosphere in which the students know that an incorrect answer is perfectly okay. They should not be discouraged, but eager to learn. If the teacher fosters this atmosphere, the students won't worry about it.
It was good to see that 4 out of 5 of the students already had a grasp of how to solve a pythagorean theorem problem. The assessment could have been more difficult, but it was meant to be a basic review so that more difficult problems and real life application could be presented in the actual lesson.
Overall, I wouldn't change much about this assessment. I think the problems are things that would be solved by being in a classroom atmosphere all year and by being in a larger setting. It will take practice to use this "Favorite No's" activity well, but I think it is well worth it.