Andee
I teach introductory statistics students at the college level and introduce this idea as well, that they have usually seen before, thanks to high school teachers like you. But I think you’re right, that sometimes intuitively the idea of the strength of a linear relationship is lost.
I use CODAP as my primary teaching tool and I love to tell this story about my 7 year old son as an illustration of the power of data visualization. One day (as he often does) my son looked over my shoulder as I was preparing a lesson. I had a data set from the World Health Organization’s happiness report. This is a poll done by Gallup of several thousand people from many countries to measure different things about their life, GDP, healthy life expectancy, social support, happiness, etc.
I had the graph below open and told him that the bottom axis showed us how much money on average the people in a country make and the “sideways” axis is how long they can expect to live. I asked him what story he could tell me about how much money people make and how long they can expect to live. He thought for a moment and drew a circle around the dots between 7 and 9 on the x-axis and 45 to 65 on the y-axis. He said these people don’t make as much money and don’t live as long as these people (drew another imaginary circle from 10 to 12 on the x-axis and 65 to 80 on the y-axis). So I prodded and said well what does that mean? He said I guess that means a country that makes more money should live longer. And we discussed why that might be the case. He’s got it! That’s correlation from the mouth of a 1st grader. I think sometimes that by the time students have gotten into high school and college they have so many tools, it’s hard for them to step back and see the big picture.
I would love to hear of any other data visualization techniques you use for kids. I also teach elementary education majors as they prepare to teach math. I love giving them tools they can use in the field.