The first template consists of the basic applet which allows the user to input data and a function with parameters (thereby essentially specifying a family of functions). The user can then change the parameters (via "scrolling" or direct keyboard input) and see the effect visually as well as numerically through the display of the least squares error that the curve makes in fitting the data. The way that points are displayed can be varied to facilitate copying data from other applications (like CAS or spreadsheets) and pasting them into this applet. Click on the screenshot below to try this template.
The second template consists of an exploration that is more focused on comparing the different ways of measuring error in the fit of a curve to a set of data points, but the basic components are the same as in the first template. In this version, the user is told a specific syntax for entering points. Click on the screenshot below to try this template.