Mailman 3 March 2009 - Edu-sig

TraceyText - A web tool for single-stepping through source code.
by Al Sweigart March 4, 2009

March 4, 2009

I've created a JavaScript tool called TraceyText. It basically creates web pages that can display the source code of a program and annotate each step with notes. This allows you to go through a run of a program step by step with explanations on the way. I created this to demo the small games I made in Python for my free Creative Commons book, Invent Your Own Games with Python ( available at http://pythonbook.coffeeghost.net ) I'll admit the tool needs more documentation and demos, but here's a demo just to see how it works: http://traceytext.sourceforge.net/dragondemo.html The website is here: http://traceytext.sourceforge.net/ -Al Sweigart

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sharing charter school resources
by kirby urner March 4, 2009

March 4, 2009

Here's a list of resources being consulted by Matsu District (AK) c/o one of the leading activists in the region. Note that Oregon Curriculum Network is included as one of these resources, plus Anna has made two special trips for planning meetings, got on the Wanderers boat, participated in a management workshop. I mentioned TECC in my Chicago talk last year, as an example of an elite charter thinking to use FOSS. Another example is LEP High, a Portland Public School standardized on Edubuntu. Riverdale High has pioneered LTSP on Redhat and so on. Like I said, Portland is FOSS capital. Boston can't hold a candle, though we work together with MIT on promoting the XO. Kirby =============== SCHOOL DESIGN RESOURCES TO DATE: 2008 Global Youth Service Day. 31 May 2008 www.gysd.net/home/index.html 2008 Model UN of Alaska. University of Alaska, Anchorage. 31 May 2008 http://www.uaa.alaska.edu/modelun/ Academy of the Redwoods • Early College High School. 31 May 2008 http://www.redwoods.edu/eureka/academy/about.asp "Accelerating Student Success." Educational Service Center of Franklin County. 31 May-June 2008 www.fcesc.org/files/Crossroads.pdf "Answers in the Tool Box: Academic Intensity, Attendance Patterns, and Bachelor's Degree Attainment — June 1999." US Department of Education Archived Information. 31 May 2008 http://www.ed.gov/pubs/Toolbox/Part5.html Bard High School Early College. 31 May 2008 http://www.bard.edu/bhsec/ Bartusiak, Marcia Bartusiak. Einstein's Unfinished Symphony: Listening to the Sounds of Space-Time. Joseph Henry P, 2000. National Academies Press Downloads. 31 May 2008 http://books.nap.edu/catalog.php?record_id=9821&utm_medium=etmail&utm_sourc… Board On Physics And Astronomy (BPA), and Engineering And Physical Sciences (DEPS). Connecting Quarks with the Cosmos: Eleven Science Questions for the New Century. National Academies P, 2003. 31 May 2008 http://books.nap.edu/catalog.php?record_id=10079&utm_medium=etmail&utm_sour… Brain Pop. 31 May 2008 http://www.brainpop.com/ Chiristensen, Clayton M., Michael B. Horn, and Curtis W. Johnson. "How 'Disruptive Innovation' Will Change the Way We Learn." Education Week 4 June 2008: 36+. Chown, Marcus. The Quantum Zoo: a Tourist's Guide to the Never ending Universe. National Academies P, 2006. 31 May 2008 http://books.nap.edu/catalog.php?record_id=11542&utm_medium=etmail&utm_sour… Committee On NASA's Einstein Program: An Architect. NASA's Beyond Einstein Program: an Architecture for Implementation. National Academies Press, 2007. 31 May 2008 http://books.nap.edu/catalog.php?record_id=9821&utm_medium=etmail&utm_sourc… Denver School of Science and Technology. 31 May 2008 www.scienceandtech.org "Dual Credit and Exam-Based Courses in U.S. Public High Schools: 2002-03 (2005)." Institute of Education Sciences National Center for Educational Statitistics. 2005. 31 May 2008 nces.ed.gov/pubsearch/pubsinfo.asp?pubid=2005009 "Dual Enrollment of High School Students At Postsecondary Institutions: 2002-03 (2005)." Institute of Education Sciences National Center for Educational Statitistics. 2005. 31 May 2008 http://www. nces.ed.gov/pubs2005/2005008.pdf. The Early College High School Initiative. 31 May 2008 http://www.earlycolleges.org. "Early College High School Initiative." Bill and Melinda Gates Foundation. 31 May 2008 http://www.gatesfoundation.org/UnitedStates/Education/ResearchAndEvaluation… "Early College." KnowledgeWorks Foundation. 31 May 2008 http://www.kwfdn.org/high_schools/early_college/ The Entertainment Technology Center. Carnegie Mellon. 31 May 2008 http://www.etc.cmu.edu/ Haycock, Kati, and Sandra Huang. "Are Today's High School Graduates Ready?" Thinking K-16 5,1 (Winter 2001): 3-17. Haycock, Kati; Craig Jerald; and Sandra Huang. "Closing the Gap: Done in a Decade." Thinking K-16 5, 2 (Spring 2001): 3-22. "Highly Effective Schools by Design." New Schools Project. 31 May 2008 http://newschoolsproject.org/page.php?p=3.1 "Home." Teacher Tube - Teach the World. 31 May 2008 http://www.teachertube.com/index.php Hopkinton Middle High School. 31 May 2008 http://www.hopkintonschools.org/hhs/ Hughes, Kathyrn L., Melinda Mechur Karp, Baranda Fermin, and Thomas. R. Bailey. "Pathways to College Access and Success." CCRC Community College Research Center. Oct. 2005. 31 May 2008 http://ccrc.tc.columbia.edu/Publication.asp?UID=340 Kauerz, Kristie. Starting Early, Starting Now: A Policymaker's Guide to Early Care & Education and School Success. Denver, Colorado: Education Commission of the States, 2001. 27 pages. ED 457 973. Kleiman, Neil Scott. Building a Highway to Higher Ed: How Collaborative Efforts Are Changing Education in America. New York: Center for an Urban Future, 2001. 37 pages. ED 453 738. Krueger, Carl. The Case for P-16 Education. Denver, Colorado: Education Commission of the States, 2002. 8 pages "Learn and Earn Early College High Schools." North Carolina Learn and Earn. 31 May 2008 http://www.nclearnandearn.gov/learnEarnHighschools.htm "Learn and Serve America Makes a Difference." The National Service-Learning Clearinghouse. 31 May 2008 www.servicelearning.org/ "LEP High School." Leadership & Entrepreneurship Public High School. 31 May 2008 http://www.lephigh.org/ Loceff, Jenna V. "How About a Nice Slice of 3.14?" Oakland Tribune 14 Mar. 2008. 31 May 2008 http://findarticles.com/p/articles/mi_qn4176/is_20080314/ai_n24938148 Louisiana State Department of Education. "Louisiana's PK-16 Vision for Education." Unpublished briefing booklet presented at Pathways to College Louisiana Case Study, Baton Rouge, Louisiana, February 4-6, 2002. Maeroff, Gene I.; Patrick M. Callan; and Michael D. Usdan (Eds.). The Learning Connection: New Partnerships Between Schools and Colleges. New York: Teachers College Press, 2001. 160 pages. "Math and Science Education." National Academies Press. 31 May 2008 http://www.nap.edu/topics.php?topic=350 "Middle College High School." South Seattle Community College. 31 May 2008 http://southseattle.edu/mchs/index.htm National Commission on the High School Senior Year. Raising Our Sights: No High School Senior Left Behind. Princeton, New Jersey: The Woodrow Wilson National Fellowship Foundation, 2001. 53 pages. ED 459 516. "National Mathematics Advisory Panel 2008 Report." Scribd. 31 May 2008 www.scribd.com/doc/2912664/National-Math-Panel-Final-Report-2008 Northfield School of Arts + Technology "PBL Overview." PBL Problem Based Learning. Maricopa Center for Learning and Instruction Web Central. 31 May-June 2008 http://www.mcli.dist.maricopa.edu/pbl/info.html "Portfolio Assessment." Houghton Mifflin Education Place. 31 May 2008 http://www.eduplace.com/rdg/res/literacy/assess6.html. "Portfolios Pathways Home." North Central Regional Education Library. 31 May 2008 http://www.ncrel.org/sdrs/areas/issues/students/earlycld/ea5l143.htm "Pyglet is a Cross-Platform Games and Multimedia Package." Pyglet. 31 May 2008 http://www.pyglet.org/ Python Programming Language -- Official Website. 31 May 2008 www.python.org/ "Rethinking High School Case Studies." West Ed. 31 May 2008 http://www.wested.org/cs/we/view/rstudy/8 Revealing the Hidden Nature of Space and Time: Charting the Course for Elementary Particle Physics. National Academies P, 2006. 31 May 2008 http://books.nap.edu/catalog.php?record_id=11641&utm_medium=etmail&utm_sour… Rosenthal, Jeffrey S. Struck by Lightning: the Curious World of Probabilities. National Academies P, 2006. 31 May 2008 http://books.nap.edu/catalog.php?record_id=11544&utm_medium=etmail&utm_sour… Schneider, Barbara, and David Stevenson. The Ambitious Generation: America's Teenagers, Motivated but Directionless. New Haven, Connecticut: Yale University Press, 1999. 360 pages. ED 430 176. "Solid Works STEM Curriculum." Solid Works Education. 31 May 2008 http://blogs.solidworks.com/teacher/2006/09/solidworks_stem.html Southwest Early College High School. 31 May 2008 http://www.secdenver.org/ STEM Education Coalition. 31 May 2008 http://www.stemedcoalition.org/ "STEM School Design Principals." Ohio STEM Learning Network. 31 May 2008 http://www.ohiostem.org/doc/stem-101/stem-school-design-principles "STEM Schools - Realworld Examples." Ohio STEM Learning Network. 31 May 2008 http://www.ohiostem.org/doc/stem-101/real-world-examples "Thinkquest Competitions." Oracle Education Foundation. <www.thinkquest.org/>. TOPP - the Open Planning Project. 31 May 2008 http://topp.openplans.org/project-home. "Update to State Dual Enrollment Policies: Addressing Access and Quality (2005)." US Department of Education. 31 May 2008 www.ed.gov/about/offices/list/ovae/pi/cclo/cbtrans/statedualenrollment.pdf Urner, Kirby. "Relevant Resources Indexed by Languages." A Mathematical Canvas. 4D Solutions. 31 May 2008 http://www.4dsolutions.net/ocn/cp4e.html Wynn, Charles M., and Arthur W. Wiggins. Quantum Leaps in the Wrong Direction: Where Real Science Ends...and Pseudoscience Begins. National Academies P, 2001. 31 May 2008 http://books.nap.edu/catalog.php?record_id=10015&utm_medium=etmail&utm_sour…

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Fwd: All PyCon Tutorials are "On"
by kirby urner March 4, 2009

March 4, 2009

Looks like we're a go for 'Python for Teachers', even if it's an intimate group, more like a planning meeting (strategy session), moving on to Phase 2 (starting from Phase 0 of course)... I did some outreach to classroom math teachers via the Chicago chipy, got some interesting feedback. Teachers seem curious, but most have not heard of Python. I think journalism is the gaping hole here. There used to be sections on science, other technical topics, but now it's all fluff about real estate, the mortgage mess, various scandals. You'd think The Oregonian would have run numerous backgrounders on FOSS topics by now, but journalists reflect the culture at large in being mostly clueless about these topics. That wouldn't be such of a problem if our economy didn't depend on using these power tools. Kirby ---------- Forwarded message ---------- From: Greg Lindstrom <gslindstrom(a)gmail.com> Date: Wed, Mar 4, 2009 at 12:24 PM Subject: All PyCon Tutorials are "On" To: PyCon Tutorial List <pycon-tutorials(a)python.org> I just received word from PyCon High Command that all tutorials will be offered (even those with less than 10 attendees signed up). Part of this is because the larger classes help offset the cost of the smaller ones, but mostly because we want to offer as much as possible to our attendees. Money is a bit tighter this year than in years past, so this is a nice gesture from those in charge. I know you all would feel cheated if I did not mention your class notes. Your pdfs are due to us on the 18th. If there is anything we can do to help you with your classes, please let us know. If your class does not lent itself to class notes, please let me know that, too, so I will not have to write you on the 19th :-) --greg

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Re: [Edu-sig] CTL: Computer Thinking Language
by David MacQuigg March 4, 2009

March 4, 2009

At 08:09 PM 3/3/2009 -0800, michel paul wrote: >On Tue, Mar 3, 2009 at 2:27 PM, David MacQuigg <<mailto:macquigg@ece.arizona.edu>macquigg(a)ece.arizona.edu> wrote: >> >>>>Before I discovered Python a couple of years ago I was experimenting with a pseudo-code approach for expressing math concepts. I had this kind of stuff in mind: >>>> >>>>factorial(n): >>>> if n < 2 ---> 1 >>>> else ---> n*factorial(n-1) >> >>>I like the feeling of action in --->, but I also like the self-explanatory "return". Any other suggestions? Strong preferences? > >Oh no, not at all. My only point in even bringing this up was that I had been trying to formulate something like a CTL awhile ago, and then I discovered Python. Wow! What I found so delightful is that the kind of pseudo-code I was contemplating looked a whole lot like Python! I thought that was a really good sign. Yeah, Python is pseudo-code that runs! It already is a CTL. > >I think the most useful CTL for integration in math education should be as close to ordinary algebra as possible. That's what I had been trying to get at. Kids in algebra classes initially get confused by this 'return'. It doesn't look like what they usually see in math. So I thought an arrow might correspond to mapping notation for functions: f: x ---> y vs. Euler notation: f(x) = y. So that's why I originally opted for the arrow. However, once they've had even a little experience, the use of 'return' isn't all that strange to them. And then, the other day when I had them create generators for their HW assignment on sequences, wow! I was really pleased that they got the idea that 'yield' just meant that the function was on hold until called again. They seemed OK with that. OK, let's stick with 'return' unless someone comes up with a better word or symbol. At least it is a common keyword in all the languages that students are likely to move up to. Nothing to unlearn. >>It would be nice to avoid in CTL the complexities of precedence and associativity rules (very non-fundamental knowledge). How about we just do all operations in the order they occur, unless you force a different order with parens. > >In terms of integration into math classes, I think it would be better to maintain the traditional order of operations. (I realize here that I'm emphasizing math/CS fusion at a secondary level, and you're talking about CS0.) But using parentheses to clarify order - definitely! And then from there, it's easy to create functional compositions. Now, I wouldn't emphasize functional composition for ALL simple arithmetic expressions - that would just be silly. But I think doing that is an excellent kind of exercise. And then beyond that - turn the functional compositions into binary expression trees! I've had kids do that in math classes as exercises in order of operations. Take a typical arithmetic expression that has several things going on and turn it into a binary expression tree. You are right. There is a "traditional order" of operations. The precedence rules for arithmetic operators are not just Python. Maybe we can get away from having to teach these rules by requiring parens in *all* multi-operator expressions. This would be equivalent to breaking a complex expression into a binary tree, if I understand your last example correctly. a + b * c ** d ==> a + (b * (c ** d))) Anything more complex than this is probably beyond CS0. a + b + c + d ==> (((a + b) + c) + d) Well, maybe we should make an exception, and not require parens when all the operators are the same. At 11:59 PM 3/3/2009 +0100, Laura Creighton wrote: >In a message of Tue, 03 Mar 2009 15:27:28 MST, David MacQuigg writes: >>At 10:00 AM 3/2/2009 -0800, michel paul wrote: >> >>>Before I discovered Python a couple of years ago I was experimenting wit >>h a pseudo-code approach for expressing math concepts. I had this kind o >>f stuff in mind: >>> >>>factorial(n): >>> if n < 2 ---> 1 >>> else ---> n*factorial(n-1) >> >>I like the feeling of action in --->, but I also like the self-explanator >>y "return". Any other suggestions? Strong preferences? >> >>We could use a symbol other than = for assignment, just to avoid confusio >>n with the comparison operator and to introduce the idea of variables as >>labels, not containers. How about: >> >>a2 --> a**2 >>a --> b --> c --> 0 > >Datapoint: the children I was teaching how to write games have all had >terrible problems with arrows. Whenever I tried to use them to indicate >anything there was this large mental thud. So my suspicion is that this >will make things harder, rather than easier. > >In explaining things I found that words worked best. > >and the words that worked were: > >'is bound to' How about := a2 := a**2 a := b := c := 0 This could be read as "bound to", "assigned to", or my preference "applied to", as in a label applied to an object. Should we put a definite "end" at the end of every function, like in Ruby? For me, it adds nothing, but a lot of folks must think it has value, or Ruby wouldn't have added it in their efforts to improve on Python. Some other suggestions from Ruby that might be appropriate for CTL: http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/to-ruby… true and false instead of True and False (and nil instead of None) elsif instead of elif require instead of import parentheses for function calls are optional :>) Ruby lurkers, speak up. I promise you will be treated with respect. I think 'elif' is kinda cute, like a baby elifant, but then I don't really know how kids think. :>) if a<b,(a, b-a); elif a>b,(a-b, b); else (a, b) -- Dave

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Re: [Edu-sig] PyWhip ???
by David MacQuigg March 4, 2009

March 4, 2009

At 04:58 PM 3/3/2009 -0800, kirby urner wrote: >I also invite visitors to my Oregon Curriculum Network site: > >http://www.4dsolutions.net/ocn/cp4e.html > >The Pythonic Math at this site is better than anything else on the Web >as of March, 2009, bar none. We're looking for something more interactive. The storyboard stuff is cool. Videos take too much bandwidth. I've always thought lectures are a terrible way to teach technical subjects, but I can see the advantage of having audio to supplement a sequence of slides, and avoid taking your eyes off where they should be focused. Bruce Eckel's Thinking in (Java, C++, Python) series is excellent, but he never finished the Python version http://www.mindview.net/Books/TIPython. There is a great opportunity here for a good teacher. Some thoughts on how we might expand on this: We need a complete online course in Python, including PyWhip, Lectures in Python (slides with audio), and a forum where students could get questions answered, like comp.lang.python, but something more private, where students won't feel shy about asking dumb questions, and more focused, where we can have a lot of discussion on a narrow topic. The topic this week is strings. This could be a "service course" for non-CS technical professionals or students who could take it as a pre-requisite for engineering and science classes. The costs of production and delivery would be very low, mainly paying teachers to participate in regularly scheduled online "classes". I can imagine a class of 200 students with two or three teachers, so questions could be answered typically within a few hours. I tried to do this with a class in C, but we had to use the University's cumbersome, officially-approved teacher-support software - no email notifications when a question is posted. That was a real problem leading to sometimes a day of delay before I could check to see if there were any questions. The login procedure was a pain. Google forums are all we need. -- Dave

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CTL: Computer Thinking Language
by David MacQuigg March 4, 2009

March 4, 2009

Apologies for the munged formatting of my original message. Here it is with leading dots to preserve the indent. To: edu-sig(a)python.org Subject: CTL: Computer Thinking Language There is an interesting article in the latest ACM {Human Computing Skills: Rethinking the K-12 Experience, Fletcher & Lu, Communications of the ACM, Feb.09, p.23}. The authors make a strong case for re-vamping our curricula: . despite our best efforts to articulate that CS is more than just programming ... . computational thinking (CT) as a skill on a par with reading, writing and arithmetic ... places the core of CS, we believe . correctly, in the category of basic knowledge. . proficiency in computational thinking helps us systematically and efficiently process information and tasks. . lay the foundations of CT long before students experience their first programming language. . Programming is to CS what proof construction is to mathematics, and what literary analysis is to English. Then they move to more more controversial statements: . Knowledge of programming should not be necessary to proclaim literacy in basic computer science. . Substantial preparation in computational thinking is required before students enroll in programming courses. and a specific proposal: . a computational thinking language (CTL) that captures core CT concepts must permeate the pedagogy. . not a programming language, but rather vocabularies and symbols that can be used to annotate and describe computation, . abstraction, and information and provide notation around which semantic understanding of computational processes can be hung. They give as an example, a description of Euclid's algorithm for finding the greatest common divisor. They suggest a syntax, which I transcribe here using <lamba> as the Greek lower-case lambda: . <lambda> a,b. if a<b,(a, b-a); else (a-b, b) At this point, they really lost me. Why would anyone go to this much effort to avoid programming language. Python's equivalent statement is just as simple (although a bit odd in its ordering): . lambda a,b: (a, b-a) if (a<b) else (a-b, b) Have these guys never heard of Python? I think the problem may be a need to avoid favoring one language over another. Any time you make a proposal to use a specific language, you get immediate opposition from folks who favor another language. In my department (Java & C++), and at our community college (Java, BASIC, Alice), I seem to have been labeled as the "Python guy", pushing "yet another language", or even worse, the guy who wants to get rid of type declarations. Python is seen as a "scripting language", something equivalent to csh or bash. To avoid being pigeonholed, I now just say "we need a more agile language". I can see the need for a CTL, and I wouldn't object to it being something other than Python, and I'm all in favor of being "fair" to the other languages. The one requirement I would insist on is that the language "compute", i.e. no ambiguity as to a result (no psuedocode). It would also be nice if CTL could be automatically translated to a real computer language, so there is a smooth transition when students are ready for the real thing. Students could test their CTL by popping it into the translator, running it in a real interpreter, and getting immediate feedback. CTL should certainly include simple functions like min(), max(), sum(), and sqrt(). It could also include functions like range(a,b), introducing the idea that functions can return something besides numbers. At this point there may be some controversy over how to treat the endpoints, but that could be worked out in compromise between the different languages. Moving on to week three of the lesson plan, we could introduce the idea of defining our own functions, adding new concepts one at a time. f(a,b): (a+b)/2 # a simple function f(a,b): (a+b)/(2*pi) # with an "outside" variable f(a,b): if a<b,(a, b-a); else (a-b, b) # adding some conditional logic f(a,b): a2 = a**2; b2 = b**2; return (a2 + b2)/2 # temporary variables and a statement sequence # control flow with multiple statements f(a,b): if a<(b-5), return a; if (b-5)<=a<=(b+5), return (a+b)/2; return b # recursion f(a,b): if a<b, f(a, b-a); elif b<a, f(a-b, b); else (a,b) This is a bit Pythonic, but only because I'm more familiar with Python than Ruby or Lua, or some other language that might like to contribute some gems. We could even invite Java, if she will come down to this level. :>) What else do we need in CTL? Would anyone like to join me in defining this new "language"? I'll write the translator to Python. -- Dave ************************************************************ * * David MacQuigg, PhD email: macquigg at ece.arizona.edu * * * Research Associate phone: USA 520-721-4583 * * * * ECE Department, University of Arizona * * * * 9320 East Mikelyn Lane * * * * http://purl.net/macquigg Tucson, Arizona 85710 * ************************************************************ *

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Re: [Edu-sig] CTL: Computer Thinking Language
by David MacQuigg March 4, 2009

March 4, 2009

At 10:00 AM 3/2/2009 -0800, michel paul wrote: >Before I discovered Python a couple of years ago I was experimenting with a pseudo-code approach for expressing math concepts. I had this kind of stuff in mind: > >factorial(n): > if n < 2 ---> 1 > else ---> n*factorial(n-1) I like the feeling of action in --->, but I also like the self-explanatory "return". Any other suggestions? Strong preferences? We could use a symbol other than = for assignment, just to avoid confusion with the comparison operator and to introduce the idea of variables as labels, not containers. How about: a2 --> a**2 a --> b --> c --> 0 A simple demo: >>> c --> 1 # move label c, not a or b >>> a,b,c (0, 0, 1) >I think some kind of a CTL approach would be especially good for a math curriculum. Maybe instead of 'Computer' TL, call it 'Computational' TL. Good point. That was actually the choice in Fletcher's article. Kids will probably shorten it to computer, however. >It's what algebra should be these days. And if your CTL also RUNS, well, so much the better. > >Most students, and probably most people, would read "2 + 2" as "2 plus 2", but notice how much more mathematically and computationally effective it would be if they could develop the habit of reading or thinking of "2 + 2" as "the sum of 2 and 2" or "sum(2, 2)". Think of the whole, the resulting value. > >And how about "2 + 3 * 4"? Again, the typical reading would be "2 plus 3 times 4", and that's ambiguous, and so in math classes we have to talk about 'order of operations', and usually the only justification we give for 'order of operations' is that we have to have some kind of social agreements in place in order to avoid confusion. Right? > >However, it is again more mathematically effective to read "2 + 3 * 4" as "the sum of 2 and the product of 3 and 4", or, sum(2, product(3, 4)). No ambiguity there! And this is how you have to think when you hook chains of functions together. This kind of stuff could be done very early in the curriculum. Doesn't have to wait for either advanced math classes or computer science. It would be nice to avoid in CTL the complexities of precedence and associativity rules (very non-fundamental knowledge). How about we just do all operations in the order they occur, unless you force a different order with parens. 2 + 3 * 4 same as (2 + 3) * 4 2 + 3 * 4 ** 5 same as ((2 + 3) * 4) ** 5 On the other hand, we don't want to teach something students have to unlearn when they get to a real language. Since CTL is for CS0-level students, we should discourage complex expressions that rely on these rules, and not drill or test students on this particular choice. It's just there to make things easy for beginners. >Math teachers often forget, or are unaware, that the ordinary arithmetic operators are themselves functions. I think it would be good for math classes to explore this kind of functional composition for very simple ideas. > >By the way, we started studying sequences today in class. What's a really good Pythonic tool for studying sequences ---> generators! Should we include generators in CTL? Seems like students at this level should have graduated to a full-featured language. Might be fun just as an intellectual exercise to play around with an "advanced CTL". I've got some ideas for unifying all methods (class, static, normal) into one simple syntax, identical to functions. Here's what I have so far. Shall I put this up on a wiki, so we can all hack at it? === CTL Syntax === # operators & expressions 2 + 3 * 4 same as (2 + 3) * 4 2 + 3 * 4 ** 5 same as ((2 + 3) * 4) ** 5 # variables as labels applied to objects a2 --> a**2 a --> b --> c --> 0 # built in functions min(), max(), sum(), and sqrt() # custom functions f(a,b): (a+b)/2 f(a,b): (a+b)/(2*pi) # with an "outside" variable # functions with multiple statements f(a,b): a2 = a**2; b2 = b**2; return (a2 + b2)/2 # same but more readable f(a,b): a2 = a**2 b2 = b**2 return (a2 + b2)/2 # function returning a tuple (sneaky introduction to objects) f(a,b): (a, (a+b)/2, b) >>> f(2,4) (2, 3.0, 4) # logic < <= == >= > != if elif else if a<b,(b-a); else (a-b) # control flow with multiple statements f(a,b): if a<(b-5), return a; if (b-5)<=a<=(b+5), return (a+b)/2; return b # recursion f(a,b): if a<b, f(a, b-a); elif b<a, f(a-b, b); else (a,b) factorial(n): if n < 2 ---> 1 else ---> n*factorial(n-1) ************************************************************ * * David MacQuigg, PhD email: macquigg at ece.arizona.edu * * * Research Associate phone: USA 520-721-4583 * * * * ECE Department, University of Arizona * * * * 9320 East Mikelyn Lane * * * * http://purl.net/macquigg Tucson, Arizona 85710 * ************************************************************ *

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Re: [Edu-sig] CTL: Computer Thinking Language
by Laura Creighton March 3, 2009

March 3, 2009

In a message of Tue, 03 Mar 2009 15:27:28 MST, David MacQuigg writes: >At 10:00 AM 3/2/2009 -0800, michel paul wrote: > >>Before I discovered Python a couple of years ago I was experimenting wit >h a pseudo-code approach for expressing math concepts. I had this kind o >f stuff in mind: >> >>factorial(n): >> if n < 2 ---> 1 >> else ---> n*factorial(n-1) > >I like the feeling of action in --->, but I also like the self-explanator >y "return". Any other suggestions? Strong preferences? > >We could use a symbol other than = for assignment, just to avoid confusio >n with the comparison operator and to introduce the idea of variables as >labels, not containers. How about: > >a2 --> a**2 >a --> b --> c --> 0 Datapoint: the children I was teaching how to write games have all had terrible problems with arrows. Whenever I tried to use them to indicate anything there was this large mental thud. So my suspicion is that this will make things harder, rather than easier. In explaining things I found that words worked best. and the words that worked were: 'is bound to' Just my 2 kronor, Laura

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Re: [Edu-sig] my Pycon nametag (ISEPP) -- isepp.org
by kirby urner March 3, 2009

March 3, 2009

FYI, here's something fun I posted to my local think tank. Terry is our president and I'm representing his ISEPP (Institute for Science, Engineering and Public Policy) at Pycon this time (2009, Chicago). Time to make that airplane reservation. Re this myth that "kids hate syntax" and need training wheels on training wheels to insulate them from "the evil lexical" (aka left brain), that's not my experience with older kids. They love eye candy, sure (who doesn't), but having consistent syntax to play with is really a big part of the fun, drag and drop GUI programming, like with Mindstorms, considered very unconstructive at this age level. I think part of the problem is Piaget dropped out early, in terms of tracking what growing minds need, had no clue about the age ranges I work with. This is just fine, as we wean them from the XO pretty early (keyboard quite tiny, Fischer-Price look only cute for so long), move to something more suitable. But that experience with Pippy was no waste of time (never mind about Squeak, we have E-toys galore in the education arcade, new physics engines coming out of Japan and places **). That being said, I'm all for Sims 2 (3,4..) and TurtleArt, anything avatar (2nd Life...), consider Valve's HalfLife2 probably one of the greatest artworks of all time (judging aesthetically) though yes, it's dark, gothic, kinda Lovecraft meets Laffoley meets... Les (CIO). I even think Alice is pretty cool (Arthur had lots of problems with Alice, I think because he wanted to champion left brain sports in older teens, right brain should be in the real out doors, using your *real* avatar, i.e. your own body -- and I'm extremely sympathetic to this, need to get to the gym myself, right after posting this, and making my plane reservation). Anyway, check math-thinking-l if you want to see more on this CTL business. I've got both threads going: both the FOSS and the "new kind of geometry" (pun on Wolfram's title) per the "Minister of FOSS" post below (yes it's dense and slow going, I admit it -- maybe shelve it for later then). Actually, I just thought of a couple more things to do before gym... like finding my iPod (for listening to Britney, a gnu math teacher for older kids, per my Kraftwerk post...). >From FOSS capital, Kirby PS: Dr. Chuck coming from Boston or somewhere, not for tutorials, so I'll plan to meet up with him later (he's the Google App Engine guy at U Mich, did tech review with him for O'Reilly, per recent archivals). Feel free to jump in on math-thinking-l if you want to do CTL more. I feel I've said the same thing enough times on edu-sig that I should mostly post elsewhere, where readers are still unfamiliar with "Coyote Academy" (charter) and/or TECC in Matsu District (AK). ** from my most recent to math-thinking-l, re FOSS in Japan (atop a proprietary physics engine, of interest to constructivists): http://www.youtube.com/watch?v=9Thjgz9Zzxs&feature=related http://www.youtube.com/watch?v=vA5PYEmreTI&feature=channel_page http://www.phunland.com/forum/viewtopic.php?id=916 ---------- Forwarded message ---------- From: kirby urner <kirby.urner(a)gmail.com> Date: Tue, Mar 3, 2009 at 10:41 AM Subject: ISEPP nametag (biz cards not needed) To: Wanderers <wwwanderers(a)yahoogroups.com> So Terry, don't think I need biz cards as geek culture is "go Google" and there's only one "Kirby Urner" so all 10K+ hits are mine -- easy to get info. But I do have ISEPP printed on the nametag and plan to talk incessantly (if queried) about how PDX is lightyears ahead of any other USA city, except maybe Matsu District AK, when it comes to FOSS in education, promoting the XO, making dreams come true for those wishing good lifestyles in our Silicon Forest (which extends from Arcata through Bellingham when I'm feeling expansive). For those who couldn't make the Livio meeting at Pauling House, maybe didn't see the write-up on Coffee Shops Network, I had the privilege of running some Akbar font slides, telling some stories, going through SQL, RSA very quickly (in more detail per ISEPP archive), stopping at 4D vs. 4D vs. 4D, a slide about geometry and where Fuller (as in Bucky) fits into the grand scheme of things. The deal here is our minimum spacefiller, or MITE, depicted on pg. 71 of Coxeter's 'Regular Polytopes' Fig 4.7a, is considered to have volume 1/8 per prefrequency concentric hierarchy, a design science gizmo or sculpture they get in Japan (Yasushi Kajikawa et al), won't teach in the Lower 48 (for no reason, just inertia and laziness, people slobs in this area). Amy Edmondson (Harvard) wrote the obligatory 'secondary literature' under tutelage of Dr. Loeb (MIT, crystallographer, friend of M.C. Escher and son), got it published through Birkhauser, 1987, respected academic press, so that should've been it, as far as leaping over hurdles ('Synergetics' in two volumes already out by this time, Scribner/Macmillan, 1975, 1979). Now it was the turn of the professoriate, to pick up the ball, which mostly didn't happen, given the Ivory Tower is controlled by uber-cowards of no self respect. Enter the private sector at this point, aka Silicon Forest, Valley and others, with better eye candy, ray tracers, FOSS... we pick up the ball and run with it, Fuller's so-called design science revolution, much anticipated. We leave most universities in the dust, but we don't care, as this is Global U City, with city-as-campus (per Google Streets), not feeling like knocking on doors when we're already so entrenched. So the deal with Livio, for me, was to link this MITE thread to his phi-base of knowledge, to Koski's stuff on PolyList, which I didn't have time to explain, to Karl Menger's famous article (Eve's dad), which Livio said he'd studied, so on the same wave-length. Karl's "geometry of lumps" suggests we do "non-Euclidean" in a different way than just fiddling with 5th postulate (been there done that): let's define all primitives to be "lumps" (as "of clay") and not talk so obsessively about how they differ in "dimension" and blah blah. Yes, this undermines the whole "fractional dimensions" superstructure, build on the XYZ way of thinking (a lot of French philosophy about rez extensa), but doesn't invalidate any of the algorithms or resulting T-shirts, which really are to-die-for, i.e. Mandelbrot lives on as a "focal point" in our curriculum, along with Pascal's Triangle (or Chinese equivalent), concentric hierarchy (like in Korea), and "NCLB Polynomial" (probably unknown to most here, given this is Lower 48, an idiocracy, albiet Portland is light years ahead...). So if we're *not* distinguishing points, lines and planes as to their "dimension" in this geometry (self consistent, non-Euclidean), then what do we call them for backward compatibility? We come up with 4D (as in 4D Solutions), meaning every "lump" is an "arrow-head" or "tetrahedron", this shape being the topologically most primitive cage, or "that with an inside and outside (convex/concave)" per Euler and other topologists. The greek "tetra" means "four" and we enshrine this minimalhood with our "4D" moniker. In contrast, the literature already has two entrenched uses of '4D' inheriting from early 1900s, where we experienced an initial shakeout (Claude Bragdon, P.D. Ouspensky also players, but not much cited these days except in art books like Linda D. Henderson's). These two 4Ds maybe be anchored to Einstein and Coxeter respectively although this is just shorthand. In Einstein type writings, the "fourth dimension" is more "imaginary" (as in "imaginary time") whereas in Coxeter type writings there's nothing time-like about any of the dimensions, they're all spatial, and you can have as many as you like (J.H. Conway really into the "n-D sphere packing matrix" or "lattice" maybe he calls it). In Python, other FOSS languages, we have this concept of "namespace" with prefix "dot notation", so when teaching other geeks about all of the above, I go einstein.4d, coxeter.4d, fuller.4d and they get it. Anyway, Livio completely understood everything I was saying and had lots of good comments, which I've taken to heart, will use to modify a couple of my Chicago slides. I'm supposed to deliver a preview at Wanderers on March 17 for those interested. In the mean time, I should be making that airplane reservation. Math teachers in Chicago will be fascinated to hear all this Saturday Academy stuff, direct from the horses mouth as it were. We beat the pants off other cities, especially in the Lower 48 (not so sure about Cape Town). Kirby Urner Minister of FOSS ISEPP PS: only room for ISEPP on nametag, plus in Python Nation I'm more properly known as Minister of Education, Google's Guido our BDFL (benevolent dictator for life). Per postings to other lists, we get together and make jokes about "math teachers" who don't know about MITEs. Just kidding (as Naomi might say, an old 2D friend from Princeton (2D was the house I lived in, same as John Baez but at a different time)).

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CTL: Computer Thinking Language
by David MacQuigg March 3, 2009

March 3, 2009

There is an interesting article in the latest ACM {Human Computing Skills: Rethinking the K-12 Experience, Fletcher & Lu, Communications of the ACM, Feb.09, p.23}. The authors make a strong case for re-vamping our curricula: despite our best efforts to articulate that CS is more than just programming ... computational thinking (CT) as a skill on a par with reading, writing and arithmetic ... places the core of CS, we believe correctly, in the category of basic knowledge. proficiency in computational thinking helps us systematically and efficiently process information and tasks. lay the foundations of CT long before students experience their first programming language. Programming is to CS what proof construction is to mathematics, and what literary analysis is to English. Then they move to more more controversial statements: Knowledge of programming should not be necessary to proclaim literacy in basic computer science. Substantial preparation in computational thinking is required before students enroll in programming courses. and a specific proposal: a computational thinking language (CTL) that captures core CT concepts must permeate the pedagogy. not a programming language, but rather vocabularies and symbols that can be used to annotate and describe computation, abstraction, and information and provide notation around which semantic understanding of computational processes can be hung. They give as an example, a description of Euclid's algorithm for finding the greatest common divisor. They suggest a syntax, which I transcribe here using <lamba> as the Greek lower-case lambda: <lambda> a,b. if a<b,(a, b-a); else (a-b, b) At this point, they really lost me. Why would anyone go to this much effort to avoid programming language. Python's equivalent statement is just as simple (although a bit odd in its ordering): lambda a,b: (a, b-a) if (a<b) else (a-b, b) Have these guys never heard of Python? I think the problem may be a need to avoid favoring one language over another. Any time you make a proposal to use a specific language, you get immediate opposition from folks who favor another language. In my department (Java & C++), and at our community college (Java, BASIC, Alice), I seem to have been labeled as the "Python guy", pushing "yet another language", or even worse, the guy who wants to get rid of type declarations. Python is seen as a "scripting language", something equivalent to csh or bash. To avoid being pigeonholed, I now just say "we need a more agile language". I can see the need for a CTL, and I wouldn't object to it being something other than Python, and I'm all in favor of being "fair" to the other languages. The one requirement I would insist on is that the language "compute", i.e. no ambiguity as to a result (no psuedocode). It would also be nice if CTL could be automatically translated to a real computer language, so there is a smooth transition when students are ready for the real thing. Students could test their CTL by popping it into the translator, running it in a real interpreter, and getting immediate feedback. CTL should certainly include simple functions like min(), max(), sum(), and sqrt(). It could also include functions like range(a,b), introducing the idea that functions can return something besides numbers. At this point there may be some controversy over how to treat the endpoints, but that could be worked out in compromise between the different languages. Moving on to week three of the lesson plan, we could introduce the idea of defining our own functions, adding new concepts one at a time. f(a,b): (a+b)/2 # a simple function f(a,b): (a+b)/(2*pi) # with an "outside" variable f(a,b): if a<b,(a, b-a); else (a-b, b) # adding some conditional logic f(a,b): a2 = a**2; b2 = b**2; return (a2 + b2)/2 # temporary variables and a statement sequence # control flow with multiple statements f(a,b): if a<(b-5), return a; if (b-5)<=a<=(b+5), return (a+b)/2; return b # recursion f(a,b): if a<b, f(a, b-a); elif b<a, f(a-b, b); else (a,b) This is a bit Pythonic, but only because I'm more familiar with Python than Ruby or Lua, or some other language that might like to contribute some gems. We could even invite Java, if she will come down to this level. :>) What else do we need in CTL? Would anyone like to join me in defining this new "language"? I'll write the translator to Python. -- Dave ************************************************************ * * David MacQuigg, PhD email: macquigg at ece.arizona.edu * * * Research Associate phone: USA 520-721-4583 * * * * ECE Department, University of Arizona * * * * 9320 East Mikelyn Lane * * * * http://purl.net/macquigg Tucson, Arizona 85710 * ************************************************************ *

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