## Thursday, February 21, 2008

### 2 More Mini-Poster Ideas

In my book I discuss mini-posters, where students create a "poster" on a standard 8.5" x 11" piece of unlined paper. Recently I used this idea in two new ways:

4 Questions, 4 Mini-Posters

After a week of classwork on percents, proportions, reading charts and probability, I wanted to use an alternative assessment (I have been working under a no multiple-choice test policy since our most recent benchmark). We have a state test prep workbook that has multiple-choice questions on each objective we need to cover, but obviously I like to use this sparingly. It is not always as aligned as I might like it to be and often the scope and level of the problems is just plain overkill.

That being said, it's still useful in bits. So I asked students to make a mini-poster for each of the four topics we covered, drawing questions from the pages in the test prep workbook. So they would have four questions, four correct answers, and most importantly, the work involved in solving the four problems. While I did ask them to put some effort into making it look presentable (so we can hang them up), the 4 mini-posters were graded solely on showing the work (or writing an explanation) and the right answer.

To keep grading simple, each question was worth 15 points for the correct answer and 10 points for showing the work (although I could understand if you wanted to flip that ratio). I also then looked at the posters as a whole and took off a few points if they didn't really follow the directions (i.e. they put all 4 questions on one paper or put little to no effort into making it legible or poster-y).

Overall it gave me just as good of a picture as any traditional assessment I would have given, while allowing them the time to really analyze the problems and get help on difficult problems.

Parent Functions

Mini-posters are also useful for vocabulary that needs to be memorized, because it forces the student to visit and revisit the definition and to create visuals and examples that illustrate it. On our January benchmark, students had no idea what the linear parent function was, because we hadn't yet discussed it in class (I wanted to save it for later in the year since we would couple it with the quadratic parent function). This is one of those rare Algebra items that requires no work, just memorization like they do more frequently in history or biology.

So first we defined the two parent functions we focus on in our course: linear and quadratic. We wrote the equations (y=x and y=x2, respectively) and sketched the graphs. I explained that linear functions made a straight line graph and had no exponent higher than 1, and that quadratic equations made a U-shaped graph and had x2 as the highest exponent in its equation.

On the poster, I asked them to illustrate this, as well as an additional example from each family of functions--the babies. The parents are the most basic functions that we compare the others to, I explained, and all of the others are "babies". Besides the definition, students are asked to identify which family a given function belongs to, so this is crucial.

So their poster has two parents and two babies. I'm concerned that maybe I should have left the babies out so as not to distract them from the definition of a parent function, but I think this was simple enough that there was little confusion. I just hope my students don't go home and tell their parents, "today in Algebra, Mr. D told us to make babies."