This activity begins with students ranking a series of things. The example below asks students to rank summer activities 1 through 10, but teachers can easily substitute another category. Once students complete their own rankings, they share their rankings with partner and work together to convert those rankings into ordered pairs, which they use to plot points on a coordinate grid.

Once they plot the points, they can use the graph to look for patterns of positive correlation, negative correlation, and no correlation.

Some additional questions teachers can pose include:

1. Do you and your partner like similar activities?
2. What would you expect a graph to look like if two partners chose exactly the same rankings for the activities?
3. What would you expect a graph to look like if two partners chose none of the same rankings for the activities?
4. What would you expect a graph to look like if two partners chose opposite rankings for the activities?
5. What would you expect a graph to look like if two partners chose about half of the same rankings for the activities?

Below are two examples of student work on an adapted version of this activity, where the partners rank movies that they’ve seen to look our patterns of positive correlation, negative correlation, and no correlation.

Are we movie compatible?

(These student examples came from Cathy Yenca: https://x.com/mathycathy/status/523172651850682368)

You can find additional ideas for introducing correlation, and data on the coordinate grid (including scatterplots) in Number Lines to the Coordinate Grid, Part 2.