Physics 11 – This year every student of mine has their own Plicker card. In previous years I kept one laminated set of plickers but it was a bit of a pain to work with. It took time to hand out and collect, and it was too difficult to ensure that each student had the card number that they were assigned to. What I did this year was combine a plicker with mini whiteboards. Each student received a plicker card printed on regular A sized paper, one A sized sheet of card stock. These where then slid inside a plastic sheet protector and voila! Not only do they have a plicker card but they have an erasable surface for questions that involve writing down an answer or graph. For example, I can ask students to predict the v-t graph of an object’s motion. I still use Peer Instruction with Plickers and it continues to be a solid system to use.
Physics 11 – Today it was time again for more peer instruction. I had gone over the basics of projectiles with the class fairly briefly. Somewhat different to how projectiles are covered in BC, I delayed introducing them until after we had done unbalanced forces. At this point students can clearly identify the single force acting on the projectile and how it has constant acceleration downwards, and constant velocity horizontally. Sequenced like this, projectiles do not have any new concepts in them.
This first question required two votes, but the students had almost 100% correct on the second vote. The next question I knew would be more difficult:
The students had only one piece of the puzzle to figure out this question, and a few students picked up on it. Most did not, even after two votes. The concept that helps answer this question is that the time a projectile spends in the air depends on the vertical motion. Specifically, the more vertical distance traveled, the longer the time spent in the air.
I’m continuing to use Plickers for peer instruction, and it is working very well. The software has improved over the past year and the voting appears to be more reliable.