I wanted to see what students were capable of on their own. No peer discussion. No Desmos. I was particularly interested to see whether they could write an equation to describe the relationship they see unfolding visually, numerically, and graphically. Some could. Some could not.

As I walked throughout the room, I took note of the incorrect equations students were writing down. There were four in particular that caught my eye. Students were clearly doing some relevant work with calculating slope and (trying, anyway) to identify the y-intercept… However, the way they mashed it all together left something to be desired.

On the Fly…

So as my last few students were finishing their work, I threw together this slide, featuring the pattern they had been working with, four “out-in-the-wild” incorrect equations, and a not-so-accidental suggestion that one of the equations is correct (just to keep ’em on their toes):

We then took a blank sheet of printer paper, folded it in half, and unfolded it. Two workspaces on the front, and two on the back. We then filled each workspace with an equation as well as a table of the actual values…

…plus a show-your-thinking-on-the-page run through of each x-value, evaluated in the given equation.

In each case, the expression values didn’t match the actual values, and the equation proved to be an imposter. While this “let’s evaluate” approach was rather typical, and the discussion was somewhat predictable, the results were nevertheless quite powerful. The major issues we identified and addressed were:

1. Students lacked a go-to strategy for verifying whether their equation was valid. It’s almost as if they viewed the progression (from numerical to algebraic) as a one-way street. Our conversation helped them see how to go from numerical to algebraic, and then back again to confirm. I probably should have equipped them with this skill some time ago. Better late than never.
2. Students were working with some faulty y-intercept assumptions. The evidence suggests (and their comments confirm) that of those who got this wrong, most went hunting for the y-intercept where it’s often found: at the top of the table. “The y-intercept occurs when the x-value is zero…” is not something that has stuck with them, despite visual, verbal, and numerical attempts to drive that home. I’m cautiously optimistic that today’s conversation smashed that misconception for most students.

Side Benefit

While most students wrote an equation with a rate of change of 4 new circles per stage, I did have a few “slope stragglers” suggest equations like y = x + 4 and y = 10x + 4. As we evaluated multiple x-values in each of four equations, and left a record of our evaluating on the board, the similarities and differences rose to the surface. The connection between the coefficients of our faulty equations (1, 4, 4, and 10) and the common differences between expression results caused a few more light bulbs to turn on.

Future Use

We’ll continue to explore Visual Patterns in small groups most the time, but I think I’ll include a dose of individual formative assessment, followed by small-group or whole-class error analysis now and again. We unpacked a lot of misconceptions today, and made a number of valuable connections as well, all in a rather short period of time. Anything that draws out misconceptions so we can smash ’em to bits through class discussion is worth bringing back for an encore.

I’m a big fan of Michael Pershan’s project Math Mistakes. If you’ve never checked it out, it’s worth exploring. And while I’m meddling with your life, here’s a tip for your entire department: Start each meeting by spending five minutes exploring one of the mistakes posted on Michael’s site. On a rotating basis, have one member of the department share a “provocative” math mistake from the blog (or maybe even one from his or her own classroom). And once duly provoked… Cue the discussion!

Amble

I included the following uninspiring question on a recent assessment:

The first two assessments I graded included the following responses:

Student 1

Student 2 ((My apologies for the retype. I added some feedback before snapping a photo.))

Comment Fodder

So here’s my question (er, set of questions) for you:

1. Are these mistakes equally egregious?
2. What misconceptions are contained in the first mistake? How would you address them?
3. What misconception are contained in the second mistake? How would you address them?
4. Would you grant any credit for either response, and why?

I’ve been meaning to blog about the “assessment workflow” in my classroom, but I’ve been putting it off because (a) time is limited, especially at the end of the school year, and (b) I wanted to be mostly satisfied with my workflow before I shared anything (and I’m not there yet).

I’ll write up the full details of how assessment happens in my classroom (it’s been a major work-in-progress this year), but for now I want to share a tiny bit of background and then cut to today’s breakthrough.

The Background

Last Sunday I aired some of my thoughts and questions on this topic to @Mythagon. A few other thoughtful folks dropped by to share their own ideas and pose a few new questions for me to chew on. It left me with a clear sense (as have other conversations) that my assessment routine fails students in the category of self-feedback. I’ve been trying to foster more (and better) student reflection in our assessment routine for several months now, and those efforts are the reason I’ve pasted this quick reflection form…

…at the bottom of every new assessment I write. However, I was looking for a way to incorporate something that would require students to be more thoughtful (just shading in a couple of boxes doesn’t necessarily demand any careful consideration) and at the same time foster a growth mindset among my students.

The Breakthrough

At the end of today’s assessment (after grading them; more on that in the next post), just before collecting everything, I gave students the following directions:

Two minutes later, I collected the papers and we moved on to something else. Later in the day I went through the papers to confirm the results and scores, to get a sense of common mistakes (again, more on this workflow later), and (this part was new today!) to read the SP and STI comments.

Growth Mindset, Plans for the Future

It’s early, but I’m sensing that this could be one of the most important features of my classroom in terms of developing a growth mindset among my students. I love the blend of looking back to celebrate something and looking forward at something (and how) to improve.

I’m wondering now about the best way to incorporate this SP/STI reflection into the “aftermath” of all my assessments. The comments (see below for some samples) were physically all over the place, with some easier to read than others. It might be worth the time (and “lost” space on the page) to add a little box near the top of the assessment with room carved out for the SP and STI comments. I’ll tinker with the layout and post an update if I come up with anything promising.

Student Comments, Round 1

Here are the SP/STI reflections from the first eight papers in the stack today. Some comments are decidedly un-profound, but others are exactly what I was hoping for right out of the gate. I’m hopeful that my classroom will become a more thoughtful and reflective place through this routine. We’ll see how it goes next time.

Update from the Interwebz

@mjfenton Trying the workflow today. Will be grading today. Instead of STI and SP, I used "Praise" & "Polish" (something we used earlier)

— Jedidiah Butler (@MathButler) May 9, 2014