A majority of the pictured students were in one of the two classes I’ve taught there. I’ll be back in January 2013.
On Monday night (October 29) about 20 UPS students took me up on the offer to help crowd-source editing the latest version of my linear algebra textbook. I have converted my LaTeX source to XML (more on that later) and despite making the conversion highly automated there are still errors in the resulting HTML version. My Math 290 students have been champions at rooting out the errors.
I plan to make a physical hardcover print edition, so I want to make it as error-free as possible before committing to print copies! So I had pizzas delivered and promised a raffle for the eventual hardcover print edition. For each section reviewed, a student could add an entry to the hat full of raffle tickets. The eventual winner was Hunter Wills (that’s him in the upper right corner).
Most students stayed for an hour or two and in total we covered about two-thirds of the sections, with some receiving two looks. They seemed to do an excellent job, and now I have a huge pile of corrections to make.
I am at the African Institute of Mathematical Sciences this January, in Muizenberg, South Africa (near Capetown). I am teaching a 3-week course on Algebraic Graph Theory. I thought I might use this vehicle for some regular travel news, but now my trip is half-done and this is the first post.
Nothing too extraordinary to report. Course is going well. It has been good to be back and renew old acquaintances (staff and alumni), as well as meet and work with the new students. I’ve been on two hikes so far, an afternoon trip up nearby 500-meter Muizenberg Peak, and the other an epic day-long walk across a wide swath of Table Mountain National Park.
Some photos follow – let me know if you’d like to see more.
William Stein gave an overview of Sage, with some combinatorial tidbits. There were the usual “oohs” and “aahs” when he generated a random matrix and then produced its LaTeX code in one extra step. Josh Laison gave a very nice talk on obstacle numbers of graphs with great visuals and an on-the-fly clicker change in mid-talk. Peter Winkler wrapped up with more great visuals (cartoons, almost!) for an entertaining talk about a cop pursuing a drunk on a graph.
It was nice to see some new faces, such as Shannon Overbay over from Spokane, and some regulars from farther afield, such as John Gimbel down from Alaska.
I never have any graduate students to supervise, but many of my students go on to a graduate degree. Sometimes they even get their PhD in combinatorics. And both were present for the Potlatch. David Neel took the UPS combinatorics course the first time it was offered and studied under Bogart at Dartmouth, while Jane Butterfield did a summer research project with me and is finishing up her thesis in graph theory at the University of Illinois. Photo below, and more from the conference are here.
A textbook posted on the Internet that is “free to download” does not have any inherent freedoms. The author has a copyright and may at any time restrict your ability to make copies. You have no right to make corrections and distribute that corrected copy. Caveat emptor.
An example. Today a Google search on “linear algebra” turns up many interesting resources. On the second page of results we find a textbook “Applied Linear Algebra and Matrix Analysis” by Thomas S. Shores. It would appear the book was once available to download. Now the page says:
Welcome again. In order to enable prospective users to preview my text easily and conveniently, in the past I have put a copy of it on the web for your perusal. In the last few years I’ve received many helpful comments and appreciative notes for having done so. I would like to thank those of you who sent me these notes and comments. You have helped me substantially improve the text. I am now under contract with Springer-Verlag and the book has been published in their Undergraduate Texts in Mathematics series in hardbound and, more recently, soft cover editions. Therefore, I have removed the on-line copy. I will leave the table of contents below for informational purposes, along with errata sheets for the each version of the textbook.
So it is important to understand the difference between “free” (as in no cost) and “freedom” (free to copy, free to modify, etc, as provided in an open license).
See for yourself: Book Site, Archived Page Capture
In the case of a textbook, this begs the question: “Why are you providing your book to everyone at no cost?” I can’t answer either question for your particular situation, but I can give you my reasons for using an open license for my textbook, A First Course in Linear Algebra.
A promise. By giving readers and teachers an unrevocable right to make and distribute copies, there is no edition-churn and no possibility of the book going out-of-print. It is a promise that the book will always be available. If you have ever built a course around a book, just to see it go out-of-print, you’ll understand. And because I also distribute the LaTeX source, anyone else can maintain the text if I become unable, or uninterested, in continuing to do so.
Quality control. I believe readers are more inclined to contribute corrections when they know you are providing the book for free. My experience with my book and Judson’s abstract algebra text is that the quality can far surpass that of commercial texts. And by making corrections available rapidly via Twitter, and by posting new editions, these corrections can reach readers very quickly. I now offer my own students $5 for each mathematically significant error, confident that they will not find very many.
A responsibility. Notice too, that if I am unreasonable in accepting legitimate changes from contributors, anyone is free to fork the book and distribute the new version containing their changes. So I have placed myself under some obligation to be reasonable and prompt about responding to suggestions and making corrections (and you know that prior to using the book).
Improvements for all. If you make changes to my book (hopefully improvements), and distribute the changed version, then you must use the same license. In this way, I require that changes by others remain available to all.
Duplication. Why do I have over thirty introductory linear algebra textbooks in my office? Do we need that many? Certainly, my book will not work for every course (for example, it would not be appropriate for a class full of engineering students) but maybe three or four quality open texts on linear algebra would be sufficient. I would rather contribute one of these few texts and work to see it become as effective as possible. When I started in 2004 I would say, “The world does not need another linear algebra text, but it does need a free linear algebra textbook.”
Another reason for not using a commercial publisher: I have never missed a deadline on my book project.
So this should help explain why I have chosen the GNU Free Documentation License (GFDL). I have some strong feelings about licenses that include a non-commercial clause. More on that later.
I am frequently asked about licenses for open textbooks. I will try to only insert a modicum of opinion here and save my views for later, both the positive and the negative.
It is important to realize that an open license works with copyright. In the United States, every creative work automatically has a copyright, even if it is not stated (e.g. “Copyright 2011″) and even if there is no registration with the government. This page you are reading now is copyrighted. A copyright is a monopoly, granted by government, to allow you to control the distribution of your creative work. In the United States, this monopoly runs for your entire life, plus another 70 years for your estate.
With an open license, you give others greater rights to your work than copyright allows. At a minimum, an open license allows others the right to make copies, and to distribute copies, forever, and you may not revoke that right.
There are two principal licenses used for textbooks. One is the GNU Free Documentation License (GFDL). It will feel familiar to users of open source software, since GNU is the organization that supported much of the free software that surrounds the Linux kernel. The other is the Creative Commons license, which comes in a variety of flavors, depending on the combination of options used. This license is often used for a variety of media, such as music and photographs, so it is not as careful about talking about source material for a work, such as the LaTeX source for a mathematics textbook.
Here is a list of the common licenses, with a brief informal description of their features.
- CC-BY: Unrestricted copying, distribution and reuse in other works of any kind. Your only obligation is to ensure that the author is always acknowledged (“attribution”) as the creator of the work.
- CC-BY-NC: Adds the requirement that you may not use the work in a commercial way.
- CC-BY-ND: Stipulates that you may not produce a derivative work. In other words, the work must remain intact. For example, you could not produce a screenplay from a novel, or except a poem from one collection to add into another.
- CC-BY-SA: You may do everything allowed by a CC-BY license, but now you are obligated to license any derivative work with a CC-BY license. This feature is why this license is called a “viral” license.
- GFDL: This is another viral license, and is very similar to a CC-BY-SA in its main features. However, with its roots in licensing documentation for software, it is more explicit about making source material available as well. It also explicitly mentions textbooks as one possible use.
- CC-BY-NC-SA: This combination should be obvious.
- CC-BY-NC-ND: The most restrictive. You can make and distribute copies for noncommercial purposes and cannot reuse or extend the work.
How does these licenses work in practice? What are the advantages and disadvantages of the various options? What are my opinions about each? (Hint: I use the GFDL for my linear algebra book.) I’ll have lots more to say in subsequent posts and likely refer back here often.
This blog will mostly be a place to publish my thoughts about open source textbooks and open source software, especially when it comes to their use in teaching mathematics. And maybe I will mix in some travel news when appropriate.
I know better than to suggest any kind of regular schedule. When I have something to say, I will say it.
I am new to blogging software (WordPress) so if you see some settings that need adjusting, please let me know.