After I read a recent education blog titled “What Exactly Is ‘Understanding?’ And How Do We Assess It?”, I was left wondering if either question had been answered. The author reiterates the ambiguity of the term and the difficulty in assessing it, but neglected to provide an example. Instead, there were just more terms: apply, reflect, metacognition, interpret, synthesis. Geez, Louise! What is it, already?
In my last post, I encouraged readers to examine their test and quiz questions to determine what was being rewarded. Were students rewarded for recall? for innovation? for showing understanding? (Yikes! It’s hard to do this without throwing out even more educational-ese. Apologies to the aforementioned blog author.)
Maybe a way to define “understanding” is to be explicit about what students should “understand”.
I’m in favor of writing an understanding goal for lessons. A quick example for adding fractions would be: Students should understand that to add fractions we need to add same size pieces. This statement contains the answer to “Why do we make common denominators when adding fractions?” Another quick example for solving equations using properties of equality: Students should understand that adding the same value to both sides of an equation maintains equality and does not change the solution to the equation. This statement explains why we need to do the same thing to both sides.
To illustrate how we might assess understanding, I’ll give an example of a quick assessment I used in a classroom I visited during a PD project. The class was working on similar figures, and finding and using scale factors (this day we were focusing on the relationship between corresponding sides, the next lesson was about relationships of sides within each figure). The teacher and I had talked about what students should understand about similar figures and scale factors. We wanted students to understand that the multiplicative relationship has to be the same for each set of corresponding sides. We wanted to check if students would fall for an additive relationship. We wanted to know if students rejected a non-integer scale factor.
We asked these three questions:
- What does it mean for two figures to be “similar”?
- Are these figures similar? How do you know?

- Are these figures similar? How do you know?

We posed these three questions at the end of the lesson, and students submitted their work on the way out the door.
The results were so cool! The students’ papers fell into 4 piles based on the understanding shown in the answers.
Pile 1: There were students who answered all three questions completely and correctly. We accepted this as an adequate answer to #1:”figures with the same number of sides and angles; angles are the same; you can use a scale factor to make one shape from the other”. Some students used division to answer #3, and some used a guess and adjust strategy to narrow down the scale factor.
Pile 2: Other students answered #1 and #2 correctly (“5×2 is 10, but 8×2 is not 13″; or, “adding 3 to each side doesn’t make them similar”), but wrote something like this for #3: “there is no number times 6 that makes 15″.
Pile 3: The next pile was for students who struggled with #1, fell for #2, and said “no” for #3 with the same 6 x ___= 15 is impossible”.
Pile 4: No clue how to answer any of the questions.
The teacher and I were pretty pleased with ourselves that we got lots of information out of about 5 minutes of work from students. It was clear that the next day we needed to reinforce the multiplicative nature of similar figures. We also needed to talk about whether or not there is a number that you can multiply by 6 to get 15. And if you believe there is such a number, how do you find it?
Did we find out if students can find a missing measure given a pair of similar figures and three of the four relevant measures? Nope. Would being able to do that give us as much information about understanding? I don’t think so.
Those who know me well know I’m a crusader against using cross-multiplying with students until they show understanding of proportional relationships (other than if a/b = c/d, then ad=bc). Of course, students could answer #2 and #3 using cross-products, but I’m not convinced that introducing this early on does anybody any favors in the understanding department.
Assessing for understanding is tough. Heck, teaching for understanding is tough. Gosh, learning with understanding is tough. But it’s important.
What test or quiz or formative assessment questions have you tweaked to get at this thing called “understanding”?