Re: Interesting problem looking for a solution.

*To*: mathgroup at smc.vnet.net*Subject*: [mg122039] Re: Interesting problem looking for a solution.*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Mon, 10 Oct 2011 04:27:42 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201110090752.DAA01680@smc.vnet.net>*Reply-to*: murray at math.umass.edu

To my previous response I should add that my colleagues and I at UMass Amherst had been doing what you ask, and more, some 20years ago (or earlier) -- first with APL, later with J, and eventually with Mathematica. Part of what we did was to create problem "validators": the package not only presented the student with parametrized test data (much as on-line homework systems do these days) but then taking the student's answers, running them against solutions calculated on-the-fly by the package for the particular data, checking to see if the student's answer was correct, and reporting the results back to the student. In what we were doing, typically the student obtained an answer by writing and applying to the test data a function, or a little suite of functions (e.g., to do Gauss-Jordan row-reduction). Eventually, we even got to a meta-preparation phase: a program that would automatically create such validators. The instructor merely supplied the various functions to create the test data and to calculate the correct answers from that, and the meta-program assembled all that into the needed package. (I think we never bothered to do the meta-program for Mathematica, but we definitely did it with APL and probably J as well.) Of course one can wonder whether today the effort into doing such things on one's own is worthwhile: that's a place that on-line homework systems excel. The infrastructure is already all there. On 10/9/11 3:52 AM, Church, Gary wrote: > Hello, > > I have an (I think) interesting problem for you Mathematica gurus. > > I'm trying to create a worksheet for my students and want to be able to display the plot of a randomly generated function f[x], without them being able to access the expression which defines f; In other words, I don't want them to be able to evaluate f[x]. > > The idea is that each student will get a different function f[x] and will see a different graph and they have to determine the expression which defines f. They then have to plot the function they think is f against the actual function f[x] and turn in the two plots (or the one plot with the two graphs.) > > Is this possible? > > Thanks much, > Gary > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Interesting problem looking for a solution.***From:*"Church, Gary" <churchg@smccd.edu>