That said, reflecting on Andrew’s comment, sliders have the potential to remove the estimation or “guess” part of guess-and-check. There is some nice sense-making that comes from predicting what parameters would achieve the goal and then adjusting based on the feedback and trying again. So, when using sliders, I think I would ask students to make a prediction or series of guess-and-checks before slider play. Or try both approaches and observe.
[Before you slide, estimate/guess values for “a” and “b” that would produce a line passing through the points.]
Now retired from classroom teaching, I miss having a class to try out these ideas.
]]>As for when movable points are better than sliders… Hm. I don’t have a comprehensive answer, but I do know that sliders are one layer more abstract (algebraically) than the “change the number” approach you mentioned. And movable points add one more layer of abstraction (again, algebraically) than sliders. Or maybe it’s not a layer of abstraction, but just a “step removed” since it draws the focus away from the expression list and toward the coordinate plane.
One clear use case (given the current set of Activity Builder tools) where I use movable points: When building a screen with graph + note + input (which hides the expression list, and therefore any related sliders).
I’d love to hear more of your thoughts on this topic, either in a comment, or maybe a blog post of your own sometime. 🙂
Thanks for stopping by to chime in!
]]>I would love to see (or do!) more research on these questions. For now, I rely on my gut and whatever justifications I can hack together on a case-by-case basis!
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