Mailman 3 February 2000 - Edu-sig

Re: [Edu-sig] Lets work on the adgenda
by Dustin James Mitchell Feb. 14, 2000

Feb. 14, 2000

<agenda mode="on"> OK then. I propose we take a hierarchical approach to our agenda, then. We have as our current structure the following: I. New & Improved Tools 1. IDLE 2. Language changes II. Curricular Development The questions are: (a) Should we split the SIG along these lines? (b) How should we subdivide (II) above? <agenda mode="off"> Now, my opinions: (a) I think that, for the benefit of discussion crossover, we should keep the two discussions in the same forum, at least until the email load gets unbearable. (b) I have two thoughts on subdividing II: - Divide it by age (PS-K, 1-2, 3-4, 5-6, 7-8, 9-10, 11-12, college, adult); or - Divide it by material type (books, teaching aids, lesson plans, teacher education resources, sample assignments, etc.) Although in light of Mr. Urner's recent post, perhaps we need to first distinguish the dimension of purpose: math, math/cs, cs, or programming? Comments are welcome. Guido: if I set up some sort of web page to track development of our agenda and work done on it, can I get a link to it from the SIG page? Dustin --------------------------------------------------------------------- | Dustin Mitchell )O( | ---------------------------------------------------------------------

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Physics simulations
by Bruce Sherwood Feb. 12, 2000

Feb. 12, 2000

Concerning physics simulations: There is a long history going back over 30 years of physicists writing simulations of physical phenomena for students to play with. I claim that mostly this by itself has had little pedagogical value. The Ph.D. physicist learned a lot from the simulation, but the introductory student didn't have the background to ask or address interesting questions using the tool. One exception to this gloomy assessment is the situation where the instructor assigns carefully articulated tasks for students to work on using the simulation as a tool. It is attractive to imagine that just sitting the student down in front of a wonderful simulation will lead to learning, but in most cases it doesn't. I also want to draw people's attention to the fact that there already exists a widely used general simulation package, called "Interactive Physics." Using a graphical interface, an instructor can set up something as complicated as a tumbling tower of blocks, and instrument the simulation with graphs and meters to display velocity, energy, etc. There is a player that students can use to run these instructor-prepared simulations. There is a third-party cooperative effort to share setups. So all of this already exists. Many physics teachers have gone beyond the gee-whiz to incorporate this tool into their teaching in a sensible and thoughtful way. An important distinction can be made between simulations and visualizations. A simulation is always somewhat suspect, because it necessarily leaves out some aspects of the real world. This is why many instructors appropriately reject replacing lab experiences with simulations. Visualizations normally are not subject to this problem. For example, my colleague Ruth Chabay has produced QuickTime movies showing electric and magnetic fields in three-dimensional space. We use these movies as lecture-demonstration tools to help students visualize the 3D aspects of fields. There is no issue here of inadequacy of the model, because the movies don't simulate physical processes; rather they teach about the vector representation used by physicists to reason about fields. You can see or download these movies at http://cil.andrew.cmu.edu/emi.html A rather different use of Python that interests our group is to have students write their own computer models from scratch, rather than merely manipulating parameters in someone else's computer model. Currently in our modern mechanics curriculum (and to a lesser extent in our electricity and magnetism curriculum) we have students write programs in our cT programming language, with no black boxes. Many of the programs that the students write are numerical integrations of Newton's second law. Here is the guts of a typical student-written program for integrating the equations of motion for a planet going around a stationary star (initial conditions would be set by the student's program before entering this loop): while 1: r = sqrt(x**2+y**2) F = G*M*m/r**2 Fx = F*x/r Fy = F*y/r px = px+Fx*dt py = py+Fy*dt x = x+(px/m)*dt y = y+(py/m)*dt plot a disk at x,y This is the simplest possible, crude integration algorithm. We have students progressively cut the step size dt until the behavior doesn't change. Today's computers are fast enough that this is adequate for our purposes: we don't have to teach fancy Runge-Kutta techniques. In merely two 50-minute periods we teach the students a subset of cT adequate for writing these and related programs, and they immediately get a spacecraft to the Moon, followed by orbits, spring-mass motion, etc., all with 2D graphical output in the form of visualizing the actual motion as well as graphs of energy, etc. We can't afford to spend more than two periods teaching the language, because this is a physics course, not a programming or computer science course. A sizable minority of our freshman college science students have never written a computer program before, and many of the others have never written a program with graphics output. The goal, largely met, is to teach students the value of computer modeling, and to fix clearly in their minds the fundamental nature of the "Newtonian synthesis" -- that knowledge of positions and momenta at this moment let you predict new positions and momenta a moment dt into the future, and iterate. This view of Newtonian mechanics does not come across in the traditional mechanics curriculum, which is dominated by known motions (blocks sliding down inclines) from which something about the forces is inferred, so that open-ended prediction of motion into the future plays a minor role. We have glimpsed the possibilities of teaching Python rather than cT in those two 50-minute periods, with the possibility of students getting 3D output for free! Python, like cT, has a simple surface syntax, without lots of extra semicolons, braces, etc., and with meaningful indentation. As an existence proof we have written Python programs that look sufficiently similar to the cT programs that our students have successfully written that we can be confident that brief instruction would be sufficient to get them into computer modeling right away. Python offers us three important things that we can't get from cT as it stands, and we don't feel that cT is an adequate base to get there from here. The first is 3D graphics. Dave Scherer, a computer science sophomore at Carnegie Mellon, is developing an engine that lives as a separate thread from the student's Python program and continually (many times a second) updates a picture of the current positions of objects whose positions the student is calculating (he uses OpenGL as the underlying engine). The effect is that the student would write a purely computational program, with no graphics statements, and for free get an animated 3d display. And also for free, the graphics window lets you move the mouse to view the scene from any position. The second thing Python offers is object orientation. The student creates objects such as sun = sphere() and earth = sphere() and then computes their motions. This doesn't necessarily lead into teaching the student to create classes, but it takes some first steps in the student's education about OOP, because the student thinks about the display objects as objects, for which we have some evidence that this is advantageous. In contrast, in cT an animation is produced by erasing a disk here and plotting a disk there, and the disk is just pixels on the screen, not an object that cT remembers anything about. Students are sometimes puzzled that they can't change a position merely by changing x and y, or that a ball plows through a wall on the screen because those pixels aren't being considered by anyone. The third thing Python offers is the possibility of writing vector operations as single statements rather than as two (or three) separate statements. We probably wouldn't start students this way, but at some point during the course it may be appropriate to have them write something like earth.position = earth.position + (earth.momentum/m)*dt rather than writing earth.x = earth.x + (earth.px/m)*dt earth.y = earth.y + (earth.py/m)*dt earth.z = earth.z + (earth.pz/m)*dt The possible value in this is that it is a powerful idea to think of vectors as single entities, not merely as two (or three) separate quantities. OUR GROUP In alphabetic order, let me introduce our Carnegie Mellon group. We think we can make a real contribution to one aspect of CP4E, that of enabling students in a physics course to write their own 3D graphics programs. We are studying a variety of issues that must be addressed to make Python plus 3D viable for science students who have not programmed before. These issues include making more robust and easy to use an integrated development environment and the installation procedure, as well as the purely 3D issues. We realize that if we address these problems we may serve wider needs than our own, but we find it useful to take a very narrow focus (the novice-programmer physics students) in order to make progress. I should mention for completeness that our focus is rather different from that of Randy Pausch at Carnegie Mellon. In Pausch's course on creating virtual worlds, students use Python to control 3D models. Our focus is rather on physics students writing simulations in the context of 3D scientific visualization. David Andersen <dma+(a)andrew.cmu.edu> System designer in CIL (Center for Innovation in Learning). Wrote much of the system software for the PLATO computer-based education system at the University of Illinois in the 70's and 80's, including major contributions to the TUTOR authoring language. Initiator of the MicroTutor language (1977). For the last ten years has been further developing and maintaining the cT programming language (which is a granddaughter of TUTOR and a daughter of MicroTutor). Extensive cross-platform experience, including Windows, Macintosh, and Unix/Linux. Ruth Chabay <rchabay+(a)andrew.cmu.edu> Ph.D. physical chemist, senior research scientist in CIL and Department of Physics. Contributed to the PLATO system software in the 70's. Has written award-winning and commercial educational software in chemistry and physics, including 3D visualizations of electric and magnetic fields, and of the ball-and-spring model of a solid. Co-author with Bruce Sherwood of a new textbook for introductory university physics incorporating computer modeling. Devised a very rapid introduction of computer modeling for physics students. Regularly teaches physics courses at Carnegie Mellon in which computing plays a major role. Ari Heitner <aheitner(a)andrew.cmu.edu> Ian Peters <itp(a)gnu.org> David R Scherer <dscherer(a)andrew.cmu.edu> Ari, Ian, and Dave are sophomores at Carnegie Mellon. Ari and Dave are majoring in computer science, and Ian is a double major in physics and computer science. They all come from the excellent Thomas Jefferson High School in Alexandria VA. Dave Scherer is the person who introduced Python to us and proposed building a novice 3D graphics computing environment on top of Python. Dave and Ari were members of the TJ team that built "Fire and Darkness," a 3D computer game that won the national prize last year at the First Independent Games Festival. All three of the students were in our physics course last year and had experience with student computer modeling of physical phenomena. Dave is rapidly developing a module that runs in parallel to Python, updating the screen with often enough to give smooth 3D animations, with user mouse actions enabling change of point of view of the scene. His module talks to OpenGL. Programs using Dave's module don't make explicit graphics calls but simply update screen positions of objects such as spheres and curves. Bruce Sherwood <bas(a)andrew.cmu.edu> Ph.D. physicist, a principal research scientist in CIL and professor in the Department of Physics. Contributed to the PLATO system software in the 70's, including in particular contributions to the TUTOR and MicroTutor languages. Has written award-winning and commercial educational software in physics. Initiated the development of the cT programming language. Has written book and on-line software documentation. Co-author with Ruth Chabay of a new textbook for introductory university physics incorporating computer modeling. Regularly teaches physics courses at Carnegie Mellon in which computing plays a major role.

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Re: [Edu-sig] Hello from a CS Teacher
by Matthias Felleisen Feb. 12, 2000

Feb. 12, 2000

As some of you know, the TeachScheme! project has been following exactly the path suggested by Jeffrey Elkner: - develop pre-AP material - train teachers to deploy it at that level - work with them to convince principals and admins that teaching language A before B is okay (most believe you must teach C++ in pre-AP courses). We have trained many teachers, we have tested the material as low as 5th grade (it works), we have great comments from all kinds of teachers (comp sci, math, bio, physics). Some teachers have provided their students with material on maintaining Web trees, CGI scripts, email, etc. So students have even gone on from here doing more than plain school stuff. Questions, comments, proposals: 1. If you are a teacher, come visit our workshop: http://www.cs.rice.edu/CS/PLT/Teaching/Workshops/ See for yourself. No, I won't mind if you take the best of our ideas and use them for Python later (with acknowledgement). But if that's your primary goal, contact us as you sign up. 2. If you believe in C4PE, why not Scheme4PE? Is there an advantage of Python over DrScheme? What can we learn from you? I do like the world idea, and it was a part of our first proposal BUT it was shot down big time by some educrats. Perhaps they couldn't imagine it in the classroom. Anything else? -- Matthias From: Jeffrey Elkner <jelkner(a)umd5.umd.edu> To: "PythonEDU" <edu-sig(a)python.org> Subject: Re: [Edu-sig] Hello from a CS Teacher Date: Sat, 12 Feb 2000 11:44:37 -0500 Cc: Dustin James Mitchell <djmitche(a)cs.uchicago.edu> On Fri, 11 Feb 2000, Dustin James Mitchell wrote: > So essentially you're using Python up to but notincluding the AP class? Yes, most high schools do not offer AP as the first programming course. There is usually a prior course which is a prerequisit. I think Python's first point of entry into the curriculum will be as a first course language in both high schools and middle schools. > So in light of this and the AP problem, do we have any hope of introducing > Python at the High School level, or would our interests (CP4E, not Py4E) > be better served by developing a sensible, effective, well-supported > environment in which to teach C++? Is there anything else we can do to > gain wider acceptance of our ideas? Could we offer alternatives to the > APs? Is there any process by which we could appeal to the AP board to add > Python as a possible language? C++ is a TERRIBLE language for CP4E! And we should not let the collegeboard dictate how we should teach (they have far too much power as it is ;-) The APs will be in C++ for the forseable future. I personally do not see that as a problem. The AP course is aimed at future CS majors. I want our first year course to reach way beyond that limited population. I have been arguing to anyone who will listen that Python is the language of choice for someone who wants to use programming as a tool but not necessarily as a career. We now have a second year course for students who want more programming but not on the AP track. Many of these students will be learning more Python in year 2. For those students who do want to major in computer science and who do plan on taking the AP exam, the ought to learn more than one language anyway. C++ will be a good learning experience for them, made better by the fact that they will already have a high level understanding of modern programming concepts through their experience with Python ;-) > Does anyone have a source for examples of developed curricula in any area? > Something upon which we could model the structure of our curriculum? Here is the collegeboard's apcsc site, for starters: http://www.collegeboard.org/ap/computer-science/ jeff

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RE: [Edu-sig] Age groups
by Jason L. Asbahr Feb. 12, 2000

Feb. 12, 2000

Replying to myself: >It sounds a lot like the Lego Mindstorms robotic kit programming >environment -- but a truly visual Python IDE. Speaking of which, the last few weeks I've had a strong desire for a system that would integrate with my IDE and with my UML design tool, a system that could track interactively what classes, methods, and attributes I'm typing in the editor, store them in a meta-code repository, and present the changes in the UML diagram. Of course, such a system would generate new classes, methods, and attributes in the repository and out to the editor from changes made in the UML model. "Round trip engineering" solutions currently on the market aren't anywhere close to being this integrated (but I'm be curious to hear from users who love their RTE solution...) The IDE-for-kids system mentioned in my previous post is similar to the above description, but rather than using UML abstractions, the focus is on kid-friendly representations of lower level code steps. However, the interactive, integrated nature is the same. A great idea mentioned on this list earlier was to present learners with partially completed solutions, or simple working solutions (classes), which they would modify and extend as part of learning about the system. It strikes me that, stealing a model from Mathematica, an IDE-for-Kids could load and save project "worksheets", which could contain multimedia data and meta-data about the project in addition to the base source code. This model has been used to create some amazing eduware in the Mathematica market. Teachers could assemble worksheet projects and submit them to the PythonForge for others to download, use, modify, and resubmit. (Blue sky: the network-friendly nature of Python could be leveraged to build automatic evaluation and grading features into the worksheets...) I hope this discussion isn't perceived by some readers as vaporware. I for one intend it as an initial requirements generation and scoping discussion for project(s) that can advance the cause of CP4E. If enough developers are interested and enough educators feel one of these proposed projects would be useful, the next step is to begin analysis and design phases, with iterative prototypes to give the community something to actually play with and evaluate. Eventually (we're talking personal life goal here), I'd love to merge my interest in education with my interest in building persistent virtual worlds. The systems we are building in Ultima Online 2 would make extremely engaging educational micro-worlds. That's not our (Origin's) goal or audience right now, but that doesn't mean it won't ever be. :-) Cheers, Jason Asbahr Origin Systems, Inc. jasbahr(a)origin.ea.com

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Re: [Edu-sig] Age groups
by Dirk-Ulrich Heise Feb. 12, 2000

Feb. 12, 2000

-----Ursprüngliche Nachricht----- Von: Gerrit Holl <gerrit.holl(a)pobox.com> [...] >> 3) Elementary Education (8-10 year old) > >You can start here. The concept of variables, lists and functions can >be explained. Dictionairies too, I think. Classes will probably be only >for the very smart ones. Don't you think classes are as easy as variables? Start right with objects, before they even know there were non-OO-approaches in the past. (now, i read several posting from functional programming guys stating Haskell etc.would provide all kinds of OO, so i think they won't backstab me, although i have no notion of what OO means in a functional programming context. I also read that Python is a version of Scheme with a funny syntax. So i think they don't really hate OO.) Dirk

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Re: [Edu-sig] Hello from a CS Teacher
by Kirby Urner Feb. 12, 2000

Feb. 12, 2000

At 07:07 PM 02/11/2000 -0600, Dustin James Mitchell wrote: >On Fri, 11 Feb 2000, Kirby Urner wrote: > >> while len(primes)<nbprimes: >> if addprime(i): primes.append(i) >> # skip even numbers (only 2 is prime) >> if i==2: i=i+1 >> else: i=i+1 > >Shouldn't the latter be i=i+2, to go to the next odd number? > Dustin -- Yes, exactly, good eye! The algorithm still worked, but less efficiently. Below is a variant which computes all prime numbers _up to a maximum_ i.e. get2max(). With this one in place, I'm able to do getfactors(), which lists all the prime factors of a number. I also threw in isprime(), which answers whether any number is a prime number (1 means yes, 0 means no). Action: >>> seive.getfactors(10981) [79, 139] >>> seive.isprime(99901) 1 >>> seive.getfactors(30012) [2, 2, 3, 41, 61] >>> 2*2*3*41*61 30012 I'm not claiming this is the most efficient or super-elegant implementation of getfactor(). If others have pointers as to how to improve these examples (to put Python in a good light), I'm happy to hear them. But I'm not looking for a lot of error checking on the passed parameters. Yes you can crash these algorithms if you pass out-of-context values, but no, I'm not interested in cluttering up the code based on the "naive user from hell" model. Kirby primes = [2] # dynamic list of primes def get2max(maxnb): # return list of primes # maxnb = number not to exceed on list global primes # keep at module level while primes[-1]>maxnb: primes = primes[:-1] i=primes[-1] while i<=maxnb: if addprime(i): primes.append(i) if i==2: i=i+1 else: i=i+2 return primes def isprime(n): global primes # keep at module level retval = 0 primes = get2max(n) if n in primes: retval = 1 return retval def getfactors(n): global primes # keep at module level # return list containing prime factors of a number primefactors = [] primes = get2max(n) while not (n in primes): for i in primes: if n%i == 0: # no remainder primefactors.append(i) n = n/i break primefactors.append(n) return primefactors

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Re: [Edu-sig] Lets work on the adgenda
by Kirby Urner Feb. 11, 2000

Feb. 11, 2000

>> I move that we setup a subgroup with this as the goal. I think it is a >> bad idea to say that is all that we will do and that everyone with >> different interests should just get off the list and go away. > >As long as I and the others on this list who are interested and motivated >to establish a Python-based curriculum have a forum in which to do so, I'm >not overly concerned with exactly what that forum is called. Do others >have an opinion on this matter? What other topic would then be discussed >in this SIG? > >Dustin My sense is we've already covered this ground. We have: (a) people commited to developing exciting new Python- related learning tools, perhaps even making core enhancements to Python itself and (b) people ready to develop new curriculum using the existing tools, not waiting for any new developments (but happy to make use of whatever stuff the (a) people come up with). And probably the majority fall somewhere between (a) and (b). So what's the problem? Looks like a party to me. Speaking for myself, I'm clearly inclined in the (b) direction. I simply don't have the time or level of Python experience to be a member of the (a) team at this time. But I'm certainly OK with (a)s and (b)s sharing the same SIG. However, I don't want to waste people's time just sitting back and pumping out a lot of "good ideas" I'm not prepared to work on myself. Probably any of us could do so endlessly, without much effort -- not what I'd consider an especially valuable activity. So I guess there's another way to categorize is this: (i) those willing to do some work, either as a developer or a user of already existing assets (ii) those willing to talk about work they'd like other people to do, but without any real commitment to doing it themselves Every results-oriented list attracts a complement of (i)s and (ii)s. We gradually sort out who's in what category and move on from there. Kirby

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Re: [Edu-sig] Hello from a CS Teacher
by Kirby Urner Feb. 11, 2000

Feb. 11, 2000

At 09:26 PM 02/11/2000 -0500, Randy Latimer wrote: >Dustin, > From my experience here in Fairfax County, VA, it's very difficult >to get the high school CS teachers to support a language other than >the one currently in use by the APCS board. My approach has been to look at Python as one more useful tool when it comes to teaching mathematics. Computers, not just calculators, deserve a place in our average math class. Students need better graphing capability and more exposure to symbolic operations than today's calculators provide. It's a mark of serious over-specialization that we draw such an artificial line between "numeracy" and "computer literacy". Just because I want to program a computer, doesn't mean I want to be a computer programmer (speaking generally -- in actual fact I pay some of my bills by writing Xbase). For me, CP4E means using Python in a non-CS context. Kirby Related posts: http://www.python.org/pipermail/edu-sig/2000-February/000096.html http://www.python.org/pipermail/edu-sig/2000-February/000117.html (note, the 2nd post is bedeviled with lots of =20s which makes it hard to read -- I hate it when that happens)

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Re: [Edu-sig] Lets work on the adgenda
by Steve Morris Feb. 11, 2000

Feb. 11, 2000

Dustin James Mitchell writes: > On Fri, 11 Feb 2000, Steve Litt wrote: > > > I move we use present day Python as the centerpiece of the initiative, and > > begin designing our curriculum and materials. Do I hear a second? > > Seconded. I move that we setup a subgroup with this as the goal. I think it is a bad idea to say that is all that we will do and that everyone with different interests should just get off the list and go away.

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Getting it going
by Ulf Engstr�m Feb. 11, 2000

Feb. 11, 2000

Seems like some people have gathered up now, but still the posting is close to nothing. With what intentions do you all get into this and what kind of discussions should we have? The post from Matthias Felleisen for example wasn't really focusing on Python but on CP4E using any existing languages or creating one. Are we focusing on general CP4E or Python? Do we wanna build new tools, make smaller implications of the core language of Python, or discuss how to teach, which books are good for teaching and what books we can write? (I'm interested either way:) I've been programming for a couple of years and stumbled onto Python 6 months ago, and now I do all my programming in Python. I'm trying to help some of my friends to start programming with Python instead of C/C++ which they are beeing taught in school now, but don't get at all. Their progress in Python is a lot better however. I think Python is a perfect language to start out with and I'd sure like to teach it to people of any age. (I'm not a teacher, but I might get to teach others in my job) What do y'll think? Regards Ulf Engstrøm (mail) ulf.engstrom(a)b2b-link.com (phone) +47 6676 5863 (fax) +47 6676 5861 (web) http://www.b2b-link.com ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

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