TheProcedure, Materials, & Analysisis the bulk of where students will spend their time, as this is the place in the lesson cycle where students actually perform the lab. As soon as we're done with the very brief Introduction, we transition into the lab itself. I have students move their desks [my students are in a traditional classroom - not a lab classroom] into groups of four. I have already set up bins with all the requisite materials that students need, so once they've transitioned into those lab groups, I have a student volunteer pass out those kits to each group. While my volunteer[s] are passing out the kits, I have the students in lab groups read over both the objective, materials, and procedure, highlighting or annotating any information they don't understand. Additionally, once they've gotten their kits, I ask them to double-check to make sure that they've received all the materials listed in theirProcedure, Materials, & Analysissection.
[Materials Note: This lesson works much better if you put food coloring in the water that students are using - any color should work fine. However, to prevent students from having to add food coloring to their individual beakers, I filled up and stopped the large sink in my room and added enough food coloring to the vat of water to fully darken its color. Whenever students needed extra water [they need about 2000 mL to fill up the container], I had onepre-nominated student go up and scoop up more from my sink in the back of the room. When they were done with the lab, I just had them take all the water and pour it back in the sink in the back, which also re-filled it for the next class]
Once they have their materials and have read through the associated information, they have my full permission to start. I don't do any modeling of the procedure for them [nor do I think it's necessary] simply because in part of this lab, which is toward the end of my academic year, I want to assess their fidelity to the procedural steps - how well can they execute a written procedure - or, if they're struggling, how quickly can they solve problems together? The lab itself is relatively straightforward. Mostly, it entails adding specific amounts of water and then placing a clear and writeable plastic cover over the landscape to draw contour lineswhere the water meets the land. While they're doing this, I'm circulating to make sure that they're following the procedural steps appropriately and doing everything safely and correctly. To note,Lab SampleandLab Work IIare pictures of my students during this stage of the lab. You can see the profiles and the red water as well as the top profiles they're drawing onto.
Once they're done and they've effectively filled uptheir entire profile [see the Lab Workpicture for what this will look like when it's all filled], I have them use permanent markers and transparencies to copy down what's on their clear plastic cover onto their own transparency, and then label the associated contour lines. I do this so everyonegets the chance to draw the contour lines [seeing, for example, that they never touch or cross, and that they go up by regular intervals], but also so that I can have a reference for grading and feedback purposes [the kits are re-usable, and the writing easily washes off for the next class]. I have some examples here:Student Transparency&Student Transparency II.
Once each group is done, they're instructed to re-assemble their kit, dump out the used water back in the sink, and then dry off and clean up their respective lab tables. After that, there are some questions on theProcedure, Materials, & Analysisresource that they're tasked with.