The publisher of Scientific American and Nature is stepping into a new genre with its first digital textbook, the company announced on Thursday.

Principles of Biology, already in use at three California State universities, is a web-based introductory text. At $49, it costs about three times less than its typical paper counterpart.

It stands out from both Nature Publishing's collection of scientific journals and magazines, as well as from similarly priced digital textbooks.

Publishing Director Vikram Savkar, who left Pearson to head up Nature Publishing's new Nature Education division in 2007, says the publisher's goal is to make high-quality original science textbooks that incorporate its large library of scientific research. Whereas most publishers convert their traditional books to digital ones through a third-party book maker, Nature Publishing built its first textbook to be digital.

"Ebooks have always been about putting a pdf of traditional books online," he says of other digital textbook makers, which include companies such as Kno, Chegg and CourseSmart. "What we’ve developed is a textbook. It’s not a reader, we're a publisher."

The book includes text and diagrams one would expect from any version of a biology text as well as data sets and research articles from the publisher's archive. Nature Publishing hired about 75 experts to contribute "modules" that can easily be reordered by teachers rather than chronological chapters.

There are a few features that aren't typical of digital textbooks, such as questions that test comprehension throughout the text and a quiz at the end of each chapter that can help teachers understand class progress. But basically, Principles of Biology is just a book.

What Nature Publishing has managed to do, however, is make it a very practical book. Because it's web-based, it can be accessed on any device with a browser. It's cheap. It can be arranged to fit the syllabus of individual teachers. And Nature Education can update its web-based pages in a jiffy if, say, someone figures out how to decode the human genome halfway through the semester.

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