Questions????

Recently, I read a post by Jon Orr where he used "2 Truths and 1 Lie" as a review tool for the exam in grade 10 math and it made me think about how I could use it in my classroom. Here's my account on using "2 truths and 1 lie" in Grade 12 Calculus - what worked, what I would modify, what it showed me about my students' understanding.

I posted the function  on the board and asked my class to create 2 truths and 1 lie about the derivative of that function. My goal was to see the depth of their understanding of derivatives as well as the product rule, quotient rule and chain rule. (We has spent the previous two classes on the product rule and the quotient rule and we had covered the chain rule in this class).

I had them write their 2 truths and a lie on post-it notes and hand them in (I asked for their names on the back of the post-it and to also identify their lie on the back). My hope was to then, at the beginning of the next class, display all their post-it notes and have them as a class sort through them into truths and lies.

As I read through their responses, I didn't think the activity went that well (I did this activity in 2 classes on the same day and got the same type of results in both sections). Here are some of their answers:

One of the reasons that I thought it didn't go well was that I was not getting very detailed responses or their responses were very surface level. Most of their responses were also very similar. After debriefing the activity with a colleague, I realize that perhaps their responses showed their understanding of derivatives at that moment was only surface level. It made me reflect upon my practice - had I only focused on the algorithm and not so much on the meaning of a derivative? Was what they were producing a reflection of what I had shown them in class? If I repeated this activity as exam review at the end of the course, would I get more detailed responses?

I then questioned if this was the right type of question to ask and where might I use it to get more detailed responses. As we start the curve sketching unit in calculus, this activity may be more appropriate if when shown the equation or graph of a functions, they were asked "Determine 2 truths and 1 lie about the graph of a given function." Students would have more aspects to reflect upon and be able to create more detailed truths and lies. Would I get better responses if students were shown the equation? the graph? or both?

I also pondered using this activity as part of a conversation with students. What if I created a list of truths and lies and asked each student to identify, from the list, 2 truths and 1 lie about a function or graph and describe why they know it is a truth or a lie.

Though I was not completely satisfied with the results of the first attempt at this activity, I definitely plan on using "2 Truths and 1 Lie" again in the upcoming weeks in Calculus. The students were engaged and each student did have an opportunity to participate and demonstrate their current level of understanding.