Custom Polygraph from Desmos

It’s been a while since I’ve blogged about a math-specific activity.  But today, I spent the better part of 5 hours creating a Polygraph Activity with scatter plots on Desmos, and it was a ton of crazy math fun.  Here is the link if you’d like to use it. 

It’s kind of like the game Guess Who, but with mathematical concepts like parabolas, quadrilaterals, and systems of equations.  It’s relatively easy to make one of these activities, but incredibly complex and time-consuming to create a good one.

Christopher confirmed my inclination:

Bob and Michael had some helpful thoughts:

Here’s what I came up with for my scatter plots:




I had my husband field test it for me.  He used language like “mostly linear” when eliminating graphs but then seemed to focus on how many points are in each quadrant.  I took out the axes to see if that solves the problem but I’m worried that might make the graphs indistinguishable to students.



What I learned:

  • The Math:  By first experimenting on StatKey (thanks @rockychat3), I was able to determine the effect on the line of best fit when maneuvering points.
  • The Logistics:  The only window available is -5 to 5.  I had to edit most of my graphs to fit in that space.  Also, intermediate saving is not currently available so ensuring your graph inputs are ready to go is helpful.
  • The People: I’m never short of completely humbled when I reach out for help with something on twitter.  Thank you everyone for your input.



  1. This is great work. I can see using the ones with the axes for my seventh graders. We talk about direct and indirect relationships (through origin or not), positive and negative correlations, and strong or weak correlations. I do see the problem with the quadrant language, I am wondering if there is the option of a shorter game with maybe only 9 graphs instead of 16.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s