The National Academies Press

About Chapter Skim

Chapter Skim is one of the three research tools we provide, in addition to Reference Finder and Web Search Builder. We provide a Chapter Skim for every substantive chapter of the 5000+ publications of the National Academy of Sciences, the Institute of Medicine, the National Academy of Engineering, and the National Research Council published by the NAP.

How It Works

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter. While imperfect, it is nonetheless an effective means of enabling a reader/researcher to get the gist of a chapter, and to focus on particular pages of interest within the chapter.

We also provide the top 30 significant phrases, derived from that same chapter, in the right-hand column. Click on a term, and you will see, in context, the chunks from any page from that chapter which contain the term. From there, you can open the exact page for further, contextualized, reading. Again, though imperfect, our textual analysis approach does a reasonably good job at identifying key ideas and themes from a chapter.

We believe the Chapter Skim tool has the potential to help researchers, students, specialists, and others more rapidly make use of our online resources.

Note: some of our older publications only have rough OCRed text — machine-read from page images — which may lead to unpredictable typos and errors. Also, we have found that an early version of Internet Explorer for the Mac (no longer supported by Microsoft) responds poorly to the Javascript upon which our active links depend. Most all other platforms and browsers (Safari, Konqueror, Firefox) function as intended.

Frequently Asked Questions

Why are you doing this? Doesn't it mean people will buy fewer books?

Since 1994, when we first made our books freely available online, the NAP has tried to balance openness with financial sustainability. As part of the National Academies, the NAP's job is to ensure that its publications have maximum impact and audience, and the Chapter Skim, as well as the other research tools, helps that process. As a self-sustaining business, we believe that the more people explore the reports, the more people will be inclined to purchase them. For some reports, that's not the case, but for others it is — enough to justify continuing openness, and to justify sustaining a small technology group, who make generalized, automated presentation systems possible, within the constraints of budget and time.

In short, we err on the side of modulated, automated openness.

Page 45's skim only has a four-word sentence. What's that about?

A book page may contain a table, illustration, or other content that doesn't fit our "most substantive sentence" approach to text. We do not currently filter those pages, believing that a small chunk of content is better than none at all.

Why are there misspellings and typos?

Older publications, or very recent pre-publication versions, may only have machine-read text to work with — and use page images for online reading. Even with 99% accuracy, that results in multiple errors on a page. The Chapter Skim (as well as the Web Search Builder and Reference Finder) works with the text it has; it is financially unsupportable to "fix" what generally is used only for backend searching. The result, even for older reports, is still useful.

Is the software open source?

See Help With the Web Search Builder for more information on this question.

Can I link to a "skimmed chapter" from my own site?

Please do. We hope to see this tool being widely used to assist in better use of our publications. Simply use the URL listed in your browser, for any chapter.