Interview with Hao Wang and Robin Gandy

In 1991, I videotaped talks at the Kurt Gödel Colloquium in Kirchberg (it was supposed to be held jointly with the Wittgenstein Symposium, that got cancelled). I also videotaped a conversation with Hao Wang and Robin Gandy, students and friends, respectively, of Gödel and Turing.  I can’t for the life of me remember who the interviewer was. Anyway, you may find it interesting:

[Photo credit: San and Jane Wang]

Fall 2016 edition of Sets, Logic, Computation

The Fall 2016 edition of the OLP remix Sets, Logic, Computation is ready. As before, it includes the OLP part on sets, relations, and functions; the part on first-order logic (with natural deduction chosen as the proof system); and the part on Turing computability including the unsolvability of the halting and decision problems. The methods chapter on induction and biographies of Cantor, Church, Gentzen, Gödel, Noether, Russell, Tarski, Turing, and Zermelo appear as appendices. At students’ request, problems are now listed at the end of each chapter. Many typos and errors have been corrected, a number of examples and problems have been added, and several proofs rewritten for clarity. I’ve also added chapter summaries and a glossary. There are also a few added sections, notably introduction sections to Chapters 5 and 7, as well as discussion of Russell’s Paradox in both Chapter 1 and 6. You can order a printed copy on Lulu, or download the PDF from the builds page. SLC F16

Line Art Portraits of Logicians

You’ve probably seen some of the line art portraits of logicians we’ve commissioned. They were done by Calgary illustrator and graphic designer Matthew Leadbeater. We’re pleased to release them all now under a Creative Commons BY-NC license: anyone is free to use them in their own work, to create derivative works from them, and to share them, provided (a) credit to Matt Leadbeater is properly given and (see license terms!) (b) they are not used for any commercial purposes. They each come in two versions, one with a line below, and one with the portrait in a circle. You can download the original Adobe Illustrator files. For PNG and PDF formats, we have set up a GitHub repository. Commissioning these illustrations was made possible by a grant from the Alberta OER initiative. We gratefully acknowledge the support. [Bonus: an image file with all of them that tiles nicely, for your desktop background.] Antonelli Barcan Marcus Boole Brouwer Cantor Carnap Church Craig Curry Dedekind Frege Gentzen Gödel Heyting Hilbert Kleene Kripke Lewis Lovelace Noether Péter Post Prior Rasiowa Bowman Robinson Russell Skolem Tarski Turing Zermelo

ASL Spring Meeting at the APA Pacific, Seattle, April 2017

The 2017 Spring Meeting of the Association for Symbolic Logic will be held jointly with the Annual Meeting of the Pacific Division of the American Philosophical Association, April 12-15, 2017, in Seattle. The members of the Program Committee are Wesley Holliday, Audrey Yap, and Richard Zach (Chair).

There will be three Special Sessions:

Modality and Modal Logic

Intuitionistic Mathematics and Logic

Inclusiveness in Logic Eduction

(organized by the ASL Committee on Logic Education)

There will also be a session for contributed talks. Abstracts of contributed talks submitted by ASL members will be published in The Bulletin of Symbolic Logic if they satisfy the Rules for Abstracts. Abstracts must be received by the deadline of September 12, 2016, at the ASL Business Office: ASL, Box 742, Vassar College, 124 Raymond Avenue, Poughkeepsie, New York 12604, USA; Fax: 1-845-437-7830; email:

Student members of the ASL are eligible for travel awards.

[Photo credit: Howard Ignatius CC BY-NC-ND 2.0]

Student Satisfaction Survey Results

In the Winter term 2016, I taught the University of Calgary’s second logic course from a textbook remixed from the Open Logic Project.  Traditionally, Logic II has used Boolos, Burgess & Jeffrey’s Computability and Logic, and it was taught in Fall 2015 using that book as the required text by my colleague Ali Kazmi, and before that by him, Nicole, and me twice a year from that same book.  One aim Nicole and I had specifically for the OLP was that it should provide a better text for Logic II, since neither we nor our students seemed to be very happy with “BBJ”. In order to ascertain that the OLP-derived text fares better with students, we did something radical: we asked them what they thought of it.  Ali graciously gave permission to run the same textbook survey in his class, so we have something of a baseline.  A direct comparison of the two books as textbooks for the course is not easily made, since Ali and I used the books differently: I stuck closer to my text than he did to BBJ; I assigned homework problems from the text; and we assessed students differently, so it’s difficult to control for or compare teaching outcomes.  With small samples like ours the results are probably also not statistically significant. But the results are nevertheless interesting, I think, and also gratifying. We obtained clearance from the Conjoint Faculties Research Ethics Board for the study.  All students in each section of Logic II in F15 and W16 were sent links to an electronic survey.  As an incentive to participate, one respondent from each group was selected to receive a $100 gift certificate to the University of Calgary bookstore. The surveys were started in the last week of classes and remained open for 3 weeks each.  Response rates were comparable (23/43 in F15, 23/42 in W16). The survey was anonymous and administered by staff from the Taylor Institute for Teaching and Learning; results were not given to us until past the grade appeal deadline in W16. We asked 23 questions.  The first three regarded how students accessed and used the textbooks. In the F15 section, the textbook was not made available electronically, but students were expected to buy their own copy (about $40).  Most respondents did that, although almost a quarter apparently pirated electronic copies.  In W16, the OLP-derived text was available for free in PDF and students had the option to buy a print copy at $10. Over half the respondents still opted to buy a copy.  We asked students how they used the texts in hardcopy and electronic form.
When using the text in hardcopy, do you...
Those using the OLP-derived printed text underlined significantly more than those who used BBJ. I’m guessing the OLP text is better structured and so it’s not as necessary to provide structure & emphasis yourself by underlining. In fact, one student commented on BBJ as follows: “Very little in the way of highlighting, underlining, or separating the information. It was often just walls of text broken up by the occasional diagram.”
When using the text in electronic form, do you...
When using the electronic version (both PDF), students did not differ much in their habits between F15 and W16. More students took notes electronically in F15. I suspect it’s because the PDF provided in W16 was optimized for screen reading, with narrow margins, and so there was little space for PDF sticky notes as compared with a PDF of the print book in F15. Also notable: highlighting and bookmarking is not very common among users of the PDF. The second set of questions concerned the frequency with which students consulted the textbook, generally and for specific purposes.  W16 students used the OLP-derived text significantly more often than F15 students did, and for all purposes.
How often do you consult the text?
The difference is especially striking for the questions about how often students consult the textbook for exams and homework assignments:
Do you read the text in preparation for exams?
Do you consult the text when working on homework problems?
We next asked a series of questions about the quality of the texts. These questions were derived from the “Textbook Assessment and Usage Scale” by Regan Gurung and Ryan Martin. On all but one of these questions, the OLP-derived text scored positive (4 or 5 on a 5-point Likert scale) from over half the respondents. The discrepancy to students’ opinions of BBJ is starkest in the overall evaluations:
How engaging/interesting is the writing?
How understandable/clear is the writing?
The one exception was the question “How well are examples used to explain the material?”:
How well are examples used to explain the material?
This agrees with what we’ve heard in individual feedback: more, better examples! Lastly, we were interested in how students think of the prices of textbooks for Logic II. We asked them how much they’d be willing to spend, how much the price influenced their decision to buy it. Interestingly, students seemed more willing to spend money on a textbook in the section (W16) in which they liked the textbook better. They also thought a free/cheap textbook was better value for money than the commercial textbook.
Is the price of the textbook too high for the amount of learning support it provides?We also asked demographic data. Respondents from both sections were similar: almost all men in each (the course is mainly taken by Computer Science and Philosophy majors), evenly divided among 2nd, 3rd, 4th year students plus a couple of grad students in each (Logic II is required for the Philosophy PhD program). Student in W16 expected higher grades than those in F15, but that may well be just an effect of differences in assessment and grading style rather than better student performance.
If you care, there’s an interactive dashboard with all the graphs, and the raw data.

More Photos of Logicians

As previously mentioned, the Open Logic Project now has a separate repository for photos of logicians to illustrate your OLP-derived materials.  They are automatically included in the biographies that live in content/history.  I’ve just uploaded a whole bunch of photos that don’t have associated biographies (yet).  Some of them are not well-known, even. For the technicalities, I’ll repeat myself from the previous post:
We have a separate repository for photos: We’ve separated them because (a) the licensing issues are more complicated: some of the photos are under copyright, and we wanted everything in the main repository to be available under a Creative Commons license; (b) the main repository would become very large if it included all these pictures. To use the pictures, clone the photos repository into the assets/ subdirectory of your local OLP clone. There’s a PDF with all the photos on the build site.
Tracking down these pictures and getting permissions was (and continues to be) a surprising amount of work.  Thanks to all the people and archives who provided them and granted permissions: the IAS archives, Princeton University Library, Berkeley’s Bancroft Library, the Russell Archives at McMaster, the Archives of the Universities of Warsaw and Wittenberg-Halle, the ILLC, the Austrian National Library, the NSUB at Göttingen, the National Portrait Gallery, the Oslo Museum, Neil Reid (Julia Robinson’s brother-in-law), Libby Marcus (Ruth Barcan Marcus’s daughter), Kim Heffernan (Haskell Curry’s granddaughter), Eckhardt Menzler-Trott, Craig Smorynski, and Peter van Emde Boas. Detailed photo credits are included with the photos.  Thanks also to the Alberta OER initiative for providing some funding to do this.  And last, but not least, thanks to Joel Fuller for doing an awesome job with PhotoShop restoring some of these photos (the original Curry photo, in particular, had a big tear right through the middle)! More to come!