That was one of the best activities that has ever occurred in my classroom. Kathy, if I ever see you again, be prepared for a high-five from yours truly.
I know the phrase "assessment is a discussion" has been a buzzphrase that's been used ad naseum, but as I sat back and listened to my students discussing their presentations with each other, the truth behind that phrase came crashing into my ears. To hear students discussing what could have made a presentation a 5, explaining why they gave a team's understanding of photosynthesis and cell respiration a 3, and giving each other feedback on how a presentation could have been made more professional was educational music to my ears. It was also helping them practice needed evaluation skills, being able to recognize what quality is and what it is not--an added bonus of students having discussions with other students.
Assessment really is a discussion, but it doesn't always have to take place between a teacher and a student. Students can and should assess each other, having discussions around the evidence of understanding they create that help themselves improve their own learning. If students aren't participating in and evaluating their own learning, there won't be much improvement. And by "participating in" I don't mean filling out one mind-numbing worksheet after another; I mean true engagement with the learning process. And discussions are a great way to engage students, especially about the quality of student work.
I also had a discussion with each of my class periods about the entire assignment as a part of the "debriefing" step of the PBL process--what they found difficult, what they liked, what other challenges they faced, etc. There was one "challenge" that was brought up in every period, and that was the fact that there wasn't already a device made to remove carbon dioxide from a home of that size that they could reference. My students told me they were extremely uncomfortable with the fact that there was no way to check and see if they were "right." I had to remind them that school--and life--isn't about right answers. It's about what you can do with the information you gather--and, when designing or trying something new, there is a whole lot of uncertainty you have to face. Just like dealing with failure, having confidence and moving forward in the face of uncertainty is an essential skill needed for life inside and outside of school.
Later in the discussion, I pointed out to them that if there had already been such a device on the market their creativity would have been stifled from the outset. They all got to experience each other's creativity when they presented their Voicethreads to each other, with exclamations of "Wow! I never would have thought of that!" and "I wish I had that in my design--it would have made it better." I did point out to them later in our class discussion that if I hadn't been such a jerk (a term we use lovingly in our classroom) in the problem design, assigning them something that hasn't yet been invented, they wouldn't have seen all of the creativity that existed in their classmates, as shown in their presentations. As one student put it, "Mrs. E, I see now why you were a jerk. If there had been a device like this made already, we all just would have copied it."
Exactly. Learning isn't copying, whether it be from the internet, a textbook, or the words out of a teacher's mouth. It's having students do the creating, applying, discussing, and evaluating, and assessing....and, above all, having students practice using their own brains instead of repeating what came out of someone else's.