Doug Lemov's field notes

Reflections on teaching, literacy, coaching, and practice.

01.11.15Maggie Johnson: How Derek Pollak Excavates Error (Video)

There’s immense value is digging up and studying student errors.

With Teach Like a Champion 2.0 lining the shelves of a book store near you, we’re back at the tiller at TLaC Towers, studying and learning from teachers.  Recently we watched a lesson of Derek Pollak’s at North Star High School and were pretty inspired.  We liked this clip in particular and Maggie Johnson volunteered to write a play-by-play of some of the things we thought were useful.  Turns out the useful stuff she noted offers a pretty good guide to some of the high points of the NEW Teach Like a Champion  2.0 so I took the liberty of adding some cross-references in her write up to help readers of Teach Like a Champion 2.0  find and read more about the ideas Maggie is describing in her post.

Here’s Maggie:

Recently, the TLaC team watched a clip of Derek Pollak’s high school Calculus class at North Star High School in Newark. We were blown away by the suite of techniques he used to orchestrate a seemingly effortless Deep Excavation (Teach Like a Champion 2.0, pages 75-76; Technique #9: Excavate Error), an extended study of a common student error.  It was one of those moments that made me believe ESPN should be broadcasting highlight reels of teachers. In that spirit, here’s my best play by play of Derek’s heroic teaching.


The clip opens with Derek circulating among groups of students busily discussing their answers and engaging them about their work. The timer projected on the board counts down from 42 seconds while Derek asks a student, “What’s your final answer here?” He examines two pieces of student work in front of him. Then he asks, “Why positive?” and listens carefully to two students’ explanation of their thinking. (Teach Like a Champion 2.0, page 185, “engage while you circulate”; Technique #24: Circulate).

In an eye-blink, he is looking over the shoulder of another student and efficiently gathering more data about his class’ understanding.   (Teach Like a Champion 2.0, page 45, Technique #4: Tracking, Not Watching)

Derek calmly calls the class to attention with the phrase “Track up front,” (Teach Like a Champion 2.0, page 360, Technique #47: STAR/SLANT) and casually picks up a piece of work from the desk of one of the students he’s just conferred with in anticipation of a Show Call. (Teach Like a Champion 2.0, page 290; Show Call).

His smooth and steady transition keeps the focus on the math.  Notice he takes Kaleesha’s paper off her desk wordlessly—an “unnarrated take” (page 297 from Show Call)— signaling to Kaleesha and her classmates that Show Call is both low-stakes and routine. This seamless transaction reveals the strong Culture of Error Derek has built in his classroom; students are not only comfortable sharing their work publicly, they expect it (Teach Like a Champion 2.0, page 64, Technique #8: Culture of Error).

But it doesn’t stop there. He justifies the group’s analysis of Kaleesha’s work by revealing that he had seen the same error in the work of other classmates. “We’re about 70% of the way here for #3,” he says, “because of one common mistake. Take a look at Kaleesha’s {work}.”  In doing so, he normalizes error and tacitly signals that he has been Tracking, Not Watching— intentionally observing his students’ work to pinpoint a specific and common error. He has set himself up for a productive Show Call and Deep Excavation because he knows exactly what his students don’t understand and who doesn’t understand it.

Then Derek begins to unearth the error. He proceeds with a series of questions about Kaleesha’s first steps. Initially, he treads lightly with his Cold Calls, asking students to describe the steps at the beginning of the solution that Kaleesha has completed accurately. (Teach Like a Champion 2.0, page 249, Technique #33: Cold Call)

After building some confidence, he puts his finger on the error. “COS of 3 pi over 4 is the place where most of us got tripped up. Someone explain how you would evaluate COS of 3 pi over 4.” Notice he chooses not to “hide the ball,” but explicitly tells students where they got tripped up.  In doing so, he maintains the pace of his excavation and focuses his students’ attention on a clearly defined component of a lengthy solution.

As Kevin responds with a detailed explanation of his process Derek utilizes a version of Right is Right by cueing Kevin to use specific technical vocabulary. “When you say you do , what do you mean by that?” he says, emphasizing the word he wants Kevin to replace.  (Teach Like a Champion 2.0, page 100, Technique #12: Right is RIght)

Even after Derek helps Kevin articulate that he means rationalizing the number, Derek notes “there is still something wrong with this analysis.” Taier is eager to declare that the answer should be   , yet can’t explain why when he prompts her with a quick “because?” to Check for Understanding. (Teach Like a Champion 2.0, page 37, Chapter 1 Gathering Data on Student Mastery; sidebar: “Reliability and Validity”)

He goes to another student who also struggles to explain before calling on Faith, who discloses that in the second quadrant COS is negative. Then, Derek uses No Opt Out and immediately returns to Taier to provide the explanation she couldn’t quite articulate a moment before. And she does so beautifully.  In doing this, Derek gives Taier a crucial opportunity to demonstrate her new found understanding, publicly rehearse success, and feel safe to make and correct errors in front of her peers. (Teach Like a Champion 2.0, page 99, Technique #11: No Opt Out version 2.0 “add a star)

Not only does Derek boost engagement and accountability by unbundling the question (Teach Like a Champion 2.0, page 254), he intentionally takes a Strategic Sampling of his classroom. He doesn’t just call on the High Flyers—those  students most likely to identify and resolve the error most efficiently. He maximizes the amount that all of his students learn by intentionally directing questions to his best estimation of a statistical sample in his room. Calling on a cross-section of students not only allows him to engage those who tend to take a little longer in mastering content, but resolves other minor knowledge gaps that he likely didn’t anticipate  after only observing their written error. (Teach Like a Champion 2.0, page 36, “Strategic sampling” Technique #2 Targeted Questioning),

In all, Derek’s work highlights the inherent synchronicity of techniques that can be used to craft a truly illuminating Check for Understanding.

By the way, if you liked this clip of Derek’s teaching, there’s one of him killing the No Opt Out in the new version of the book as well.  Hope you’ll check it out!

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2 Responses to “Maggie Johnson: How Derek Pollak Excavates Error (Video)”

  1. Callielo
    January 22, 2015 at 4:19 am

    “After building some confidence, he puts his finger on the error. “COS of 3 pie over 4 is the place where most of us got tripped up. Someone explain how you would evaluate COS of 3 pie over 4.” Notice he chooses not to “hide the ball,” but explicitly tells students where they got tripped up. In doing so, he maintains the pace of his excavation and focuses his students’ attention on a clearly defined component of a lengthy solution. ”

    This is a really helpful example — I have noticed that I tend to get overly focused on the idea of “ratio” at times, at the expense of pacing and keeping conversation focused on the most important issue.

    Thanks for highlighting this bit!

    • Doug Lemov
      January 22, 2015 at 11:52 am

      thanks for your comment. one thing i tool away from my re-reading of Isabel Beck’s book on vocabulary, Bringing Words to Life, was that guided questioning is often better when it requires students to “explore” how to use information rather than what the information they don’t know is. Beck uses this to apply to vocabulary. It’s less productive to say “What do you think ‘destitute means”? when kids don’t know and then listen to them guess than it is to give them a definition and ask them to apply it. “So… could you still be destitute if you had a lot of money? what are some things you could do if you were destitute? How is destitute different from just being poor?” “can you “feel” destitute but not actually “be” destitute? How? What about the opposite?” Could a ‘magnate’ [using another vocabulary word here] ever be destitute? How” etc. ideally causing students to use the word in their examples, over and over. this, you could argue, is more rigorous than “who can tell me what destitute means?”

      that’s similar to what Derek is doing here. Not “who can tell me the mistake” but “here’s the mistake, explain why we made it? when else might this happen? how do we fix it, etc” those things build ratio too. but as you point out they tend to keep the pacing going. and they tend ot be more rigorous too.

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