Viewpoint

Writing an Open Text JIM HEFFERON

AND

ALBERT SCHUELLER

The Viewpoint column offers readers of The Mathematical Intelligencer the opportunity to write about any issue of interest to the international mathematical community. Disagreement and controversy are welcome. The views and opinions expressed here, however, are exclusively those of the author, The publisher and editor-in-chief do not endorse them or accept responsibility for them. Articles for Viewpoint should be submitted to the Editor-in-Chief, Marjorie Senechal.

oday you can get many things from the Internet, from driving directions to cute videos. Increasingly, you can also get mathematics material, including openly available texts. Because this is a growing trend, Albert Schueller and Kent Morrison brought together some prominent authors of these materials in the Open Source Mathematics Textbooks contributed paper session of the 2014 Joint Mathematics Meeting. By highlighting this movement, they, and we, hope to encourage others to support it and perhaps even to join it. It is a chance to expand beyond just the model of traditional commercial publishing. The discussions brought out clear themes, including a need for standards such as explicit licensing statements, a need for the wider academic community to understand this activity as scholarship, and a desire to foster communities of people doing this work. We will discuss those, with an emphasis on best practices for authors. First, a word on words. We avoid ‘‘free’’ because its everyday meaning ‘‘without cost’’ overshadows the additional meaning needed here of ‘‘and with permission to share’’ (see [11]). We shall say that a work is ‘‘open’’ if it comes with explicit permission that it can be shared. If the author also shares the work’s source then we shall say ‘‘open-source.’’ Some of the texts now available on the Internet were at one time published traditionally but have since been released for download. That is generous of the authors and former publishers, but our focus here is on the increasingly common practice of developing new college-level mathematics texts directly for open distribution.

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Advantages of Open Texts Traditional publishing has strengths but so does distributing a text openly. Developing a text is a great deal of work. To do it, an author or team must feel that they are making a contribution to the mathematics community. Distributing this work openly means that they can make this contribution exactly as they feel is best, without the market considerations that traditional publishers must face. They can write on any subject, at any length. They can take a new approach, choosing to disregard marketing considerations such as what content to retain or what to omit. There is no required format or theme, or even medium—since they need not be concerned about digital rights management, open works can lead in the use of emerging technologies. They can make innovative use of graphics, video and audio, or interactive content [25], and can make it available to all, regardless of location or ability to pay. There is, at least in principle, no constraint.

Ó 2016 Springer Science+Business Media New York DOI 10.1007/s00283-015-9606-1

An open text can be written without time pressure. This helps an author who must develop the material over a longer period of time than the traditional publishing cycle allows, such as an author from a school where professional development time is limited. If called for, an open text project could take a major turn in emphasis or approach without needing to justify the change to a publisher. Some licenses (see the later discussion) allow users of a work to modify it to better suit their needs. Some licenses even allow others to incorporate the material as part of a work of their own. This kind of sharing is very far indeed from what is traditional. Deciding to distribute a work openly has a philosophical appeal. Many mathematicians want to share their subject, and open distribution lets them do so with a minimum of friction. Authors may also be inspired by the Free and OpenSource Software movements. For instance, on the opensource software Sage [28], a text depends then its author may feel that making the text open-source as well is only fair. Some authors perceive that allowing open access to their work is a strategy that helps it gain the widest possible audience. They may also feel that by inviting a larger community to participate, a better work with a longer shelflife could emerge. This additional freedom for authors might result in more texts and a wider variety of texts available for adoption. So freedom for the authors could provide more freedom of choice for adopters. Finally, price. Many people are dismayed at the cost of texts. Authors of open texts often express satisfaction that they are helping to buck this trend [31].

Best Practices Only recently has open distribution of texts been possible, but nonetheless, some best practices have emerged. In this section we will speak to authors, describing these practices. The unifying principle is to make the work as usable as possible. Have a license. It should state the conditions under which the work can be used, shared, and possibly extended. It should appear prominently on the text’s home page and inside the text itself. Many potential adopters will not use the material unless there is a license and they can accept it. Pick a license that is already well known. A great starting point is the Creative Commons site [1]. Another fine choice is the GNU Free Documentation License [15]. We urge authors to grant users as many rights as possible. Each of us has been glad for materials that are available under a liberal license, from Wikipedia to Sage. Sharing back in a like way is appealing. Furthermore, this kind of license may help a text attract interest from users and contributors, just as Wikipedia and Sage have done. Consider accepting contributions. Many open texts today are due to a single author or a small number of authors. A tight group can maintain a clear vision and consistency of writing style. However, text projects with multiple contributors have the potential to grow faster, to leverage a wider knowledge and skill base, and to benefit from a variety of experiences.

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Fig. 1. Creative Commons buttons such as these visually represent the wide variety of license options. Typically, a badge similar to one of these examples is placed on a work with a Creative Commons license.

For example, a project might include not just experts in the mathematical subject area but also a graphic artist for figures and a JavaScript programmer for interactive components. Or a project could have one group working on the main text and another working on an ancillary such as a solution manual. A project that accepts contributions should consider adopting a mission statement to define the coverage, approach, and audience, and also to act as an advertisement for potential contributors. An example is Sage’s mission statement: ‘‘Creating a viable free open source alternative to Magma, Maple, Mathematica, and Matlab’’ [29]. The project could also adopt a style manual, defining symbol conventions and terminology as well as source standards such as file naming. It should also provide a document that describes how to download and compile the files. Conversely, we urge potential authors, before starting a new work, to look for an ongoing project to join, simply because one complete project is better than two incomplete ones. Consciously choose the target media. Most open texts are written for paper or for a paper-like PDF. But other media can be appealing options. Some works, such as an interactive Sage notebook, don’t make sense on paper at all. In this case the target technology makes the media decision. An obvious medium to consider is the web language HTML. It includes the capability for audio, video, and interactive components. A downside is the need to skirt browser incompatibilities and perhaps to handle changing web standards. Also, although MathJax [22] has improved this situation considerably, browsers can have trouble showing mathematics, particularly in breaking equations across lines. Targeting multiple media is tempting. Most available input systems with multiple media output are not good with mathematics. One that shows promise is MathBook XML [21], which aims to have a flexible and semantic input language with output in LATEX, HTML, PDF, or ePub. Its development is ongoing but there is already a gallery of works at the given address.

A point to weigh in choosing media is that many readers prefer a paper copy. A print-on-demand service frees authors from handling orders or returns (check whether the service will sell blocks of books to college bookstores). Note that the decision to offer a paper version may affect how frequently to post updates, since adopting faculty do not want students to have different versions. If it fits the medium, use LATEX . LATEX has high-quality output, is open-source, and is available on all major computer platforms. It comes with a large and capable suite of tools for mathematical authors, such as a number of options for publication-quality graphics, including PGF/TikZ [30] and Asymptote [6]. LATEX’s ongoing development ensures that these tools will remain useful for many years. And LATEX aids collaboration because it is widely known in mathematics and fits well with the source code tools discussed next. Use version control and a public source repository. Developers of open texts can learn from developers of open software. This includes managing the project’s source in a version-control system such as Mercurial [23] or Git [12] (these are open-source programs). For readers who are unfamiliar with version control: authors continue to write input files in the usual way but a version-control system replaces the tangle of backup files that many projects have, ensuring that everything is saved and that anything can be restored to any previous state. They also allow authors to experiment with a separate branch of development, perhaps where a chapter is divided in two and some other chapters are adjusted, in such a way that after the experiment is complete the authors could elect to have the experiment take over as the main branch, or they could fall back to the source without the experiment. These systems really shine in the area of collaborative work. If two people edit a chapter at the same time then the system automatically folds together the two sets of changes (unless there is a conflict, which must be adjusted by hand). For more, see the tutorials for Mercurial [24] and Git [14]. Open-source projects typically make the source available on a free public repository such as Bitbucket [7] or GitHub [13]. This is especially helpful for a project that solicits contributions. As a bonus, these sites offer other features such as bug reports and mailing lists for feedback. A reason for keeping work in a public repository, which may not occur to a person just starting a project, is that it can help a work survive the loss of its author. Having the source material available publicly allows others to continue the work. This is in some ways like publishing research findings in public journals for others to build on. Help people find it. Every open text should have a home page that is indexed by the major search engines. One possibility is a public repository, as discussed earlier. Consider submitting the work to sources of reviews such as the American Institute of Mathematics (AIM) list of Approved Textbooks [4] and the MAA [17], and to journals that include book reviews (see the MAA list [2]). Authors should also submit to sites that are clearinghouses for opentext information, including College Open Textbooks [9], the

Open Educational Resources Commons [19], Open Textbooks Library [20], and Merlot [18]. Note that these sites provide a link to a work’s home page, rather than keeping a copy of the work, so if an author updates the text on the home page then the site’s information is still accurate. This is another reason to have a home page. There are other options for dissemination that lie between just putting up a link and traditional publishing. One is a scholarly repository such as Digital Commons [10], which aims to provide a secure permanent location for the work that is available for indexing, including by Google Scholar [16]. Finally, although the audience for an open text certainly includes course instructors, often its potential audience also includes people using the text for self-study. So authors may consider making it discoverable through social media. For instance, Reddit has a subsite to post links to open mathematics texts [27].

Supporting the movement The open-text model depends on the existence of writers to produce the works as well as on the existence of readers to use them. Both groups can take steps to help this innovation flourish. Authors should follow the best practices named earlier, notably that of prominently stating a suitable license. This fits with the larger theme of making the work usable, which includes helping others to find it. For authors, perhaps the most radical shift from current practice is that when considering starting a new project, they should first see if it makes sense to work within or to extend an already existing open-sourced one. In general, authors should consider adopting a collaborative style of work. This has the potential to lead to richer texts. Open authors would also benefit from a chance to share experiences. A first stop is the Open Mathbook blog [26], where members of the community share ideas through guest posts and discussions. We expect the evolution of best practices for open textbook development to continue in forums such as this blog and the JMM sessions. Open Mathbook The Open Mathbook blog is a place where members of the community share ideas through guest posts and discussions. We explore new and existing open texts, best practices, publishing techniques, novel technologies, public policy related to open educational resources, and a host of other issues. Guest posts are welcome. Visit the blog http://www.openmathbook.org and follow the ‘‘Contact Us’’ link to make a suggestion.

In the wider academic community, the simplest way for an individual to support the development of open texts is to use them. Adoptions speak volumes. The biggest institutional hurdle is formal evaluation. Professional credit at the time of a formal evaluation such as a tenure or promotion review is often the only substantial reward that an academic author receives, whether under a traditional publishing model or with open distribution. But with traditional publishing, a text can be judged partly on the perceived quality of the publisher, the adoption rate, and peer review. In the wider mathematics community also, authors receive recognition, awards, etc., Ó 2016 Springer Science+Business Media New York

based in part on such measures. These factors are sharply diminished for open-text authors. There is now no formal peer-review process, and no imprimatur of a prestigious publisher. And, free distribution makes adoption rates difficult to determine. So mathematicians interested in developing a healthy ecosystem of open texts must help those responsible for evaluation of open-text authors to understand the value of this work as scholarly activity. Articles such as this one, professional meetings like the JMM, organizations such as the AIM [3], and advocacy by groups such as the Association of Research Libraries [5] are steps. But there needs to be more done inside individual institutions. When authors of open texts are involved in formal reviews, they and their references should argue strongly for recognition of the activity. This case is made stronger by noting that the author has followed best practices and is innovating in pedagogical approaches, and perhaps in leveraging technology. By providing such information, they will also help the next person to make a similar case. Organizations such as the MAA, AMS, and SIAM can help by visibly recognizing this type of professional activity. Conference organizers can invite open-source authors to speak and they can provide space in the form of special sessions and minicourses for members of the community to share ideas. Development of awards programs and funding opportunities would also help to recognize and inspire such activity. Most important, the open-text community, both writers and readers, needs to have systematic methods of reviewing open works and recognizing ones of superior quality. We should fund and formalize review processes such as those provided by AIM and the Open Textbook Library [20]. Finally, some standard method of tracking open-text use would help add more certainty to this process. The authors thank the participants of the JMM session, and the referees, whose discussions greatly informed this article. All of the links below are current as of 13 August 2015.

[3] American Institute of Mathematics home page, http://www. aimath.org. [4] Approved Textbooks,

American Institute

of

Mathematics,

http://aimath.org/textbooks/approved-textbooks/. [5] Association of Research Libraries home page, http://www.arl. org/index.php. [6] Asymptote 2D & 3D TEX-Aware Vector Graphics Language John

Bowman,

Andy

Hammerlindl,

http://sourceforge.net/

projects/asymptote/. [7] Bitbucket, Atlassian, https://bitbucket.org/. [8] Categories of free and nonfree software, GNU foundation, http://www.gnu.org/philosophy/categories.en.html. [9] College Open Textbooks home page, http://www.collegeopen textbooks.org/. [10] Digital Commons, Berkeley Electronic Press, http://digital commons.bepress.com/. [11] Free

software,

Wikipedia,

http://en.wikipedia.org/wiki/Free_

software. [12] Git, Git Team, http://git-scm.com/. [13] GitHub, GitHub Team, https://github.com/. [14] gittutorial, Git Team, http://git-scm.com/docs/gittutorial. [15] GNU Free Documentation License, Free Software Foundation, http://www.gnu.org/licenses/fdl-1.3.en.html. [16] Google Scholar home page, Google, https://scholar.google. com/. [17] MAA Reviews, Mathematical Association of America, http:// www.maa.org/press/maa-reviews. [18] Merlot project home page, http://www.merlot.org. [19] Open

Educational

Resources

home

page,

http://www.

oercommons.org. [20] Open Textbook Library home page, http://open.umn.edu/ opentextbooks/. [21] MathBook XML, Beezer R, Farmer D, Blood S, http:// mathbook.pugetsound.edu/. [22] MathJax, MathJax Consortium, http://www.mathjax.org/. [23] Mercurial, Selenic, http://mercurial.selenic.com/. [24] Mercurial Tutorial, Selenic, http://mercurial.selenic.com/wiki/

Jim Hefferon Department of Mathematics Saint Michael’s College Colchester, VT 05439 USA e-mail: [email protected] Albert Schueller Department of Mathematics Whitman College Walla Walla, WA 99362 USA e-mail: [email protected]

Tutorial. [25] Open Texts on the Web, Taking the Next Step, Michael Doob, Notices of the American Mathematical Society, vol 61, no 7, Aug 2014,

[1] About the licenses, Creative Commons, http://creativecommons. org/licenses/. [2] Additional Sources for Math Book Reviews, Mathematical Association of America, http://www.maa.org/publications/maa-reviews/ additional-sources-for-math-book-reviews.

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http://www.ams.org/notices/201407/

[27] /r/mathbooks, Reddit, https://www.reddit.com/r/mathbooks. [28] Sage Mathematics Software, W. A. Stein et al., http://www. sagemath.org. [29] Sage Mission Statement, The Sage Development Team, http://wiki.sagemath.org/faq#What_is_Sage. [30]

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p 756–758,

rnoti-p756. [26] Open Mathbook blog, Albert Schueller (maintainer), http:// www.openmathbook.org.

PGF and TikZ – Graphic systems for TEX Till Tantau, Christian jects/pgf/.

Feuersa¨nger,

http://sourceforge.net/pro

[31] What We Are Doing about the High Cost of Textbooks, American Institute of Mathematics, Editorial Board, Notices of the American Mathematical Society, vol 60, no 7 (August 2013) p 927–928, http://www.ams.org/notices/201307/rnoti-p927.