The most important ideas to listen to in this lesson are how students describe the long-term trend. Do they see that the trend shows that artic sea ice is declining? Use their ideas on 1.5 Finding a Trend in Arctic Sea Ice Worksheet to determine where they are in their thinking at this stage. Look to see if they feel comfortable using the trend as evidence to make a prediction about what will happen in the future. At this point in the lesson, students should be able to explain that all data representations represent the same system, but in different ways. Listen to their ideas in the final discussion using Slide 8 to determine if they are comfortable explaining why and how scientists simplify large data sets to identify trends, or if they need to revisit the activity before moving on.
When watching the video, students may need help identifying the difference between (a) seasonal variation of ice extent between winter and summer, and (b) the overall declining trend.