Building a graph with Tinkerplots:
Data icons first appear in a haphazard arrangement in the plot window. The icons are colored along a gradient for the variable selected on the data card, in this case "Backpack Weight." The greener the icon, the heavier the backpack. Clearly, the heaviest backpack belongs to Faith.

You can see Keilor's data card (above, upper left), and his data icon highlighted in the plot window (right). Dragging the data icons separates them into groups.

Students use controls to stack , order separate , fuse , or display icons as value bars .

pair 1:

One pair of students ordered the data vertically by "Backpack Weight" and then stacked them:

Then they changed the icon color to display "Grade" and saw that the heavier backpacks at the top of the stack belonged to students in the higher grades (purple and peach):

pair 2:

Another pair of students first separated values of "Backpack Weight" horizontally and then stacked them vertically:

Then they changed the icon color to "Grade" and observed that students in grades one (green) and three (blue) clustered at the lower end of the graph and thus tended to have lighter backpacks:

Finally, they separated "Grade" into four groups, which they thought made the differences more obvious:

pair 3:

A third pair of students displayed "Backpack Weight" as value bars, and then ordered them:

They then changed the icon color to "Grade" and observed that students in grades 1 (green) and 3 (blue) clustered at the lower end of the graph and thus tended to have light backpacks: