Marcia McKinley-Pace wrote:
> have points taken off if they don't. My personal view is
> that they will probably never use either the definitional or
> computational formulas again (b/c they will use SPSS or
> calculators) so I would rather have them practice the
> definitional formulas, to reinforce the theory.
I wonder - does anyone have the students work with the
"computational formulas" anymore? I don't, for the same reasons that Marcia
gives here. Are those formulae just another relic, perpetuated by the system
of textbook review (one reviewer writes: "Hey! Where are the computational
formulae? That's how _I_ learned it!", and the author backs down)?
I love the Excel method, though I haven't used it formally. In each
class now I get at least one or two students who ask if they can just set up
a spreadsheet to do the repetitive calculations (e.g., for the standard
deviation). It's simple to say "Yes, but it needs to show columns for the
deviations, and squared deviations, as well as label the sum of squared
deviations". If they can do that, they understand as well as they need to.
Paul Smith
Alverno College
Milwaukee
