I start by eliciting prior knowledge to learn what students already know about tides. I do this by asking students to respond to general questions using a Kahoot Game I created. (Kahoot is a game-based site that allows students to play using their computer, cell phone, or any other Wifi-enabled device.) By using this site, I can immediately see the results and can assess my students' background knowledge, while they have fun playing a game.
We review the graphic organizer as a class, reviewing parts of the video that for questions that seem confusing or need reinforcement. I have students use a different color ink to revise their answers as we go over them together. This helps provide a visual cue between their initial understanding and the additional information they need to learn to understand the concepts.
Now that students have learned a little background information about tides, I have them participate in the Gravity and Tide Lab, courtesy of Carolina Curriculum. In this lab, students read two separate texts, watch a short teacher demonstration, and graph the high and low tides for a two week period to learn more about the lunar cycle and the relationship between the Earth, the Moon, gravity, and tides. (See my reflection for more information.)
After completing the lab, I have students complete the Kahoot Game again, so that both they and I can reassess their understanding of the material. This, combined with their participation in the discussions and their work in the lab, help me to assess whether or not they understand how tides are caused and how they are related to lunar cycles.