Book Review: OpenStreetMap: Using and Enhancing the Free Map of the World
The physical bulk of the tome OpenStreetMap, Using and Enhancing the Free Map of the World suggests the depth of the mapping project itself. OpenStreetMap is an effort to create nothing less than a free-to-use map of the world. The book itself is 335 pages and was written by three authors: Frederik Ramm and Jochen Topf, both IT professionals with several years of OSM participation in Germany, and Steve Chilton, a UK geography professor and OSM participant who aided in the production of this first English edition.
The first question that popped into my head as I opened the book related to the book's currency. Would not a book like this be out-of-date even a few months after publication? The OpenStreetMap project, along with the data collected and the tools developed to make the map possible, are all continuously in flux. So are the people involved. Just last month, Steve Coast, who founded the project and later co-founded a company (CloudMade) to build on it, announced he'd taken a position at Microsoft.
The authors had the same concerns and only created the English edition after three German editions had done well and demand for a new language edition was high. They also made clear in the introduction that a website would be updated regularly to reflect any key changes. (I didn’t see any citations since the book was published in Sept. 2010.) Still, the authors were careful in the text to make clear the fluidity of the venture, for example, by noting the licensing changes which were expected during the writing. They are currently in progress. (More on that later.)
The book is divided into four parts: an introduction, a section for data contributors, a section on making and using maps based on the data, and a final one on “hacking” OSM. The short introductory section is quite good and weaves in some of the key beliefs of the project. In particular, there is a clear preference for originally surveyed data. While it’s possible to include full datasets that meet the licensing requirements, and to “trace” imagery licensed for that purpose, the “safest” way to build the dataset is by heading out onto the landscape with GPS and notebook in hand.
The three technical sections on how to contribute and edit data, how to use the data in projects or apps, and the section on hacking (aimed at the most technical of readers) are clear and detailed. They read much like any other software manual or “how to” guide and include many illustrations of interfaces. I found these chapters easy to read with plenty of detail. The contribution section covers a lot of ground because it details not just the two commonly used OSM editors (the Potlatch online editor and the downloadable JOSM editor) but also a fleet of other open source editors and other tools that are available.
The most important chapters, I think, relate to licensing. That, in my experience, is the least understood aspect of open source software and openly licensed content. The authors are careful to explain that they are not lawyers but they’ve clearly worked hard to understand and then explain in understandable language the dos and don’ts of the current license (Creative Commons Attribution-Share Alike, CC-BY-SA). They detail what data can be incorporated into OSM and how OSM data can be used for your own commercial or non-commercial use when following that license. There’s also a short section noting the license changes as the project slowly edges toward the Open Database License, ODbL.
I was pleased to see that the authors do not paint OSM as a panacea of mapping, and their language suggests that they are a bit surprised at how well the whole OSM process works. They also note, respectfully, the areas where critics take aim, even as they encourage readers to join the OSM effort.
I imagine this book will be used first, as an intro guide and later, as a reference book. I don’t think it’s the sort of manual you’d take into the field. It’d be a great reference for an educator looking to incorporate OSM into a course or as the focus of a course. And it’d be a well used reference at a mapping party.
The other valuable role this book plays, though this was not its goal, is to highlight the challenges of geodata capture, even with today’s modern tools. The book necessarily deals with data formats, topology, raster and vector, routing, attribute selection, licensing, map rendering, Web GIS. These are the same challenges that have faced cartography, automated mapping and GIS throughout history. This project, in so many ways, is no different.