Newsgroups: comp.lang.logo Path: news.media.mit.edu!bloom-beacon.mit.edu!gatech!usenet.ufl.edu!draco.nova.edu!alpha!gowj From: gowj@alpha.acast.nova.edu (Big Jim) Subject: Re: Intuitive recursion Message-ID: Sender: news@draco.nova.edu (Usenet Administrator) Organization: Nova University References: <2ghs6e$qe2@agate.berkeley.edu> Date: Sat, 8 Jan 1994 17:54:24 GMT Lines: 59 matt@cory.EECS.Berkeley.EDU (Matt Wright) writes: >Tommaso Russo asked me to post this to the newsgroup, since he can't do it >himself: >----------------------------cut here-------------------------------- >Read in comp.lang.logo From: matt@volga.EECS.Berkeley.EDU (Matt Wright) >>...the approach is very informal and relies on the students getting an >>intuition. (...) >>Now, I wouldn't want to try to teach recursion this way, >Why not? See below. >>but I would hope to >>mix in the informal and the intuitive along with the more rigorous, >>mathematical type stuff. (...) >>Everything that I understand well about >>computer science I understand both on a formal level and on an informal >>level, and I think teachers should be able to (eventually) expect the same >>thing of their students. (...) - Matt >I agree completely. >Teaching recursion (true recursion, not just final one) has been a >puzzle for me for years. The most refractary student I had was my wife >(a math teacher that teach logo to mentally handicapped adults as part >of a therapy). Surprisly, the most receptive were university students >interested in fortran and already do-loop minded (yes, recursive >fortan exists!) for applications like quicksort and adaptive >quadrature. I realized that the main problem was not logical >difficulty, but rather NEED. Fortan students feel the need for >implementing a fast sort routine, and so appreciate the quicksort >algorithm and the recursive feature of a language. Children (and my >wife) do not feel the need for solving hanoi puzzles or exploring a >tree. >>From where, at a very low level, a need for recursion can arise? The >best answer I found up to now is from the need for TRANSPARENCY. >Transparent graphic procedures (i.e. those that leave the turtle in >exactly the same state it was) are higly appreciated as soon as one >realizes that they can be inserted in and deleted from a >superprocedure at will. Unfortunately, the way in wich transparency is >usually introduced, e.g. The Watts (Dan & MOlly) call this clear state in thier 1992 learning and assessment book on Logo. > Tommaso Russo > Russo@Area.Trieste.It -- Linc, James Internet: Gowj@novavax.nova.edu; UUCP: gatech!uflorida!novavax!gowj Songs of Solomon 2:12 "...the voice of the turtle is heard in our land." James Gow P.O. Box 700585 Miami, Fla. 33170. Disclaimer [Is this really necessary? I have a hard time getting people to understand that!]