Friday, November 28, 2014

Video Error Analysis (Anti-Khan style)

Something I tweeted this week:
Crystal (colleague) and Lynda (fellow) wanted to know more about this. So here's the story:

The previous week, I met with one of my high school fellows who teaches Algebra to freshman. As with all my fellows, it's been an extreme pleasure to work with her because she's hungry for ideas and will take suggestions and run with them. It was so cool to walk into her class this past week and see her running with an idea, again.

She had already taught her students ways to solve linear systems; graphically, substitution, elimination, etc. On this day, she prepared six short videos of her solving linear systems and linear inequalities using Educreations on her iPad. Students were to watch the videos and do error analysis, reporting the following on their handout:
  1. Identify the mistake(s) for each question.
  2. Explain what should have been done.
  3. Fix the mistake and complete the question correctly.
Each video was between 60 and 90 seconds in length. We both discussed what we thought would be most effective for her students and short videos was a must. Have you ever noticed how the majority of Khan videos can be extremely lengthy? Sal Khan usually talks (and repeats himself) while writing things on his digital blackboard. To me, that's a waste of someone's time. It's like you watching me type this blog post while I reread every sentence two or three times, stalling so I can finish typing. Another thing I can't stomach in Khan videos is when he fumbles around searching for colors to write with. Lastly, I find it unfortunate that the videos rarely suggest the viewer to pause and consider what's happening. Here's an example. Sorry, here's a 9+ minute example:

I suggested my fellow pause the recordings often and write the equations "offscreen" when not recording. Then, press record again when she's ready to talk and/or write something important on her screen. She also took advantage of this offscreen time to select different colors in order to emphasize different equations, steps, lines, or shading (linear inequalities).
*See the video structure below with suggested notes and style points.

It took my fellow one prep period on a minimum day to create six videos, a supplemental handout, upload the videos to Educreations, and create hyperlinks on her Haiku page for students to access all the videos. That's super impressive. Talk about an activity with meaningful and HUGE return from an efficient investment in her prep time.

When debriefing with my fellow after class, she was completely ecstatic.
I asked her, "What elements made this awesome?"
She replied:
  • it was video and new
  • they liked figuring out someone else's mistake
  • the videos were short
  • students could pause, rewind, and start the video over
  • using Desmos to show a graph of the original equations at the end (comparison)
  • gave students the idea to use Desmos to check their work/answer
  • self-pacing
  • very little hand-raising or students drowning
  • the videos were easy to make
  • she passed out the handout and said "go" instead of modeling
  • the handout had a simple structure 
  • the students did most of work, not the teacher
I love this last element the most. The two of us talked about this specific element the previous week. Now she experienced it first-hand and it's an amazing feeling. As an observer, it was awesome to see the students working hard on a meaningful task and helping each other out so it allows her, the teacher, opportunities to calmly circulate and provide support where necessary.

Student engagement and interest were high. Discussions were plenty and authentic. Students were thriving using thinking skills in the "Analyzing" category of Bloom's Taxonomy or Strategic Thinking category of Webb's Depth of Knowledge. Here's a tip I suggested when I noticed some kids plowing through a video and hadn't caught the mistake: pause and make predictions. The video structure will explain pausing and predicting more.

Video Structure:
Part 1: She takes about 8 seconds to explain her plan
*All of this was written on the screen prior to her pressing record. Style points.

Part 2: Multiply the top equation by (-5) in order to eliminate the x-terms

*Here's where we need to ask students to pause and predict what the top equation will look like after being multiplied by (-5).
  • Model this for students.
  • Build "pause and predict" prompts into the video. 
  • Circulate the room and ask students to pause and predict.
SO valuable. Don't skip "pause and predict".

Part 3: Write the new equations "offscreen". Don't record yourself writing these equations.
*Notice the new equation is written in red inkStyle points!
**Pause and predict what it will look like when combining the equations
***Catch the mistake?

Part 4: Combine the two equations.
*Another great use of "offscreen" writing.

Part 5: Find the value of y.

Part 6: Substitute the value of y into one of the original equations.
*Yet, another use of "offscreen" writing here.

Part 7: Solve for x this time.
*Ask your students to check for reasonableness.
**Find an alternate way to validate (or invalidate) their conclusion.

Part 8: Insert a screenshot of the system graphed in Desmos.
*Mind grenade: the graph doesn't match the algebraic procedure.
**HUGE style points by inserting a visual representation of the correct answer.

For those of you who don't have 1:1 devices in your schools, no sweat. I still recommend you make a video of some sort. Borrow an iPad from someone. Create an Educreations video for error analysis. Use the tips and techniques mentioned here. Your videos should be less than 90 seconds. Play it to your class. Pause the video to have students make predictions and/or discuss possible errors. I guarantee you, good things will happen.

Style points,


  1. Wow! This is amazing! Thank you for blogging about it. -mrschungsta

    1. Thanks Chungsta! Let me know if you want to pursue this.

  2. Replies
    1. Thanks Cathy.
      I'd like to know more about your comparison between EdPuzzle, ThingLink, Educreations, and anything else you've used in this arena. Thanks.

  3. Very interesting blog post. I totally agree that this type of video allows greater student engagement compared with the typical Khan academy video (sit and absorb). Love the suggestions to shorten the videos.

    If students spot the error right away to they jump to worksheet or do they watch the entire video? I see advantages to both, especially because it is helpful for them to see how to check their solutions by graphing on Desmos.

    Thanks for good ideas before my class begins systems of equations.

    1. Re: "If students spot the error right away to they jump to worksheet or do they watch the entire video?"
      Either option is fine. My fellow made a couple videos where there were more than one mistake made.

  4. Great idea. To reinforce pause and predict perhaps these directions could be embedded into educanon. Then the teacher could monitor student responses as well.

    1. Thanks for the tip. I'll check out eduCanon.

  5. Nice post. I have been doing this sort of thing as warm ups.....find my mistake and fix it. I was recording short videos in Explain Everything. I then shared the Project file with the kids. They could watch the video and then edit my work right over top in Explain Everything. Then share that video back, or to others. Very powerful! Thanks for sharing this post!

    1. Hi Jon,

      Great idea. I appreciate you sharing with us!

  6. Hi Andrew-

    Couldn't agree more about the importance of short videos. When creating any type of tutorial and even recent 3 act math tasks, I really focus on making it fast and to the point. Long videos like Khan can get the job done, but it is probably only appealing to an audience who really WANTS to do well in math. That learner would probably be able to figure it out with or without the video because of their willingness to learn. What about the struggling students who shut down years ago when they came to the conclusion that they weren't any good at math?

    Short and engaging videos, whether questioning to peak curiosity or challenging students to find mistakes, are much more likely to yield benefits than a videotaped lecture with a monotone speaker.

    Always fun to read your blog. Thanks!

    1. Hi Kyle,

      Thanks for posting. I'm also thinking it helps model what I would want from my students if/when they ever submit a video assignment to me. I don't have the time nor want to sit and view anything longer than a minute.

      Thanks for your kind words.

  7. Hi Andrew,
    Love the post, I have a few questions.
    1. Is this a whole class activity or are they watching this individually?
    2. Is it just one video or do they click on the pictures like we are? If not can we have a link to the whole video?
    3. What software did she used to record the onscreen dialogue?

    Thanks in advance,

    1. Hi Damian,

      Thanks for asking and I apologize for not being clear enough. Answers:
      1) The students are watching individually on their screens, but working in groups of four so they can ask each other questions throughout the videos.
      2) The teacher created about 6 videos. I took screen shots of her videos to give you a glimpse.
      3) She used the iPad app Educreations to create and record the videos.

  8. Sal's repeating of phrases to allow for his Wacom pen to catch up to his mouth drives me batty. "Let's say that they tell us that the sum, the sum, of two numbers, sum of two numbers, is seventy and they defer (sic), they defer, or maybe we could say their difference, they defer by eleven, by eleven." I can wrap my head around teachers not having issues with other aspects of KA that I find troubling: the highly procedural focus, the obvious lack of planning, the very idea of teaching as a friendly voice patiently delivering content, etc. But this?! I don't know how educators who recommend KA to me get past it.

    This problem was brought up at a workshop I recently attended. The speaker's fix was to have students record their videos first (no narration) and double the speed (in iMovie). Then, students recorded the audio while watching their sped up videos. This keeps the feeling of seeing a worked example unfold but removes, for the most part, the "defers, defers, defers, by eleven, by eleven" thing.

    1. Testify!
      Oh man, the repeating of phrases, repeating of phrases is tough, I say tough, to handle. Thanks for sharing the process you picked up at a recent workshop. I'll have to keep that one in mind. Thanks Chris.