- What's the right warm-up activity? Should I even have a warm-up for this lesson?
- How much time should I allow for discussion?
- How do I engage students in today's topic, building off of previous knowledge while inching toward new ideas?
- How do I manage the flow of students and materials?
- And, finally, how much time should I dedicate to "content download" (aka, "lecturing")?
Recently, my colleague and I crafted a lesson that featured essentially zero lecture time. Indeed, when I looked back at the day, I recognized only thirty seconds of downloaded content! Despite this - in fact, likely because of this - the lesson was a huge success resulting in near total engagement throughout the day and leaving students confronting a significant gap in their knowledge base. If your vision of teaching looks like non-stop lecture, punctuated by the occasional Q&A, then this lesson might surprise you:
The Lesson: Connecting the Respiratory System to Cellular Respiration - Changing Scales for Deeper Understanding
The Plan:
1) Warm-up - Free write in response to the following prompt: Obviously, the respiratory system takes in oxygen from "out there" for delivery to the body. The phrase 'cellular respiration' implies a kind of breathing at the cell level. What connects these two 'respirations?' In other words, how does oxygen get from 'out there' to 'in here?' (Two minutes to respond privately, two minutes to share in pairs, five minutes to discuss as a class.)
2) Model it! In small groups, grab markers of a single color and some newsprint and draw your best response to the warm-up prompt. Label your drawing so that your thinking is apparent. (20-25 minutes)
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| The large- and small-scale respirations |
3) Gallery Walk - Groups hang up their newsprint models in the classroom as students use post-its to leave comments about what they see ... this is done SILENTLY so that group-think can be minimized. (Five minutes of setting expectations, followed by seven minutes of actual commenting.)
Silently adding comments
4) Scientist Talk - I gather all in a large circle and facilitate a discussion of common features (the "consensus" view) in the models. In addition, students are pressed for details where models seem fuzzy; this highlights the limit of our current understanding. (Ten minutes or so)
5) Revise Your Model - In the final few minutes, students take a second color marker and amend their models based on the feedback from classmates. (Fifteen minutes or less).
As a teacher, you can see my role is front-loaded with planning and heavy on facilitation. Students, on the other hand, are actively engaged in sharing and communicating their understanding. They retrieve their prior knowledge, complete with partial ideas and misconceptions, and work to make their thinking visible for others to review. One of my biggest responsibilities is to make sure that the environment is a safe one - revealing one's partial understanding is risky business and not done in a hostile environment.
Where did we land? Our consensus was at the system level - the transportation of oxygen via the circulatory system and the (fuzzy) interface between the respiratory and circulatory systems. This makes complete sense as we have just finished a unit on body systems and students could demonstrate some solid background at this level. What they were unsure of were the transitions: how, exactly, does oxygen transfer from the lungs to the bloodstream and, on the other end, from the blood stream to the cells. Here, students vaguely drew arrows with little understanding of the mechanism of the transport. At the end, we are positioned well to re-introduce a concept from our homeostasis studies (diffusion, driven by concentration differences) as an answer to this question - the topic of our next lesson!
So, where was the content? While there were ample opportunities to chime in with all sorts of content ideas, I chose just one moment to do so. As we discussed the warm-up problem, it became apparent to me that students had the pieces of cellular respiration - at times mentioning water, energy, carbon dioxide, glucose, and oxygen - but not a complete picture of the chemical process. Before transitioning to making models, I urged them to "write this down:"
Glucose + Oxygen -------> Carbon Dioxide + Water + Energy
That's it! One clear statement of a process on which we will spend much more time in the future. I thought having that common statement would help keep the focus on the transfer of oxygen from 'out there' to 'in here.' In fact, some groups decided to incorporate the movement of glucose to the cells, as well. While not a requirement, it added some welcome variety to the student models.
A modeling exercise like this shifts the teacher's role from 'provider' to 'facilitator.' Surely, it would be impossible for students to construct all of life science in this way. But looking for ways to have students make meaning of their knowledge - in a variety of ways - is good practice.
What are your favorite ways to have students make meaning?
