How to Read a Book suggests that when you read a book for the first time you should deliberately skip-read it, unhesitatingly skipping over detail sections. -- Martin Fowler (DuplexBook)In the past, I read technical books very differently. Actually, I always read as fast as I could; however, I would also do every example in technical books. I found that if I did the examples, I would remember how to do something without needing to reference the book. This worked fine for me, but I was working off a poor assumption: I wouldn't want to reference the book.
Then, Obie Fernandez and I worked together on my first Ruby/Rails project. I had been doing fat client development in C# for the previous 2.5 years, so I had a lot of catching up to do. I told Obie I was a bit overwhelmed by the number of books I wanted to finish (Ruby books, Rails books, Ajax books, CSS [no more tables!]). He gave me a great tip: Read books to create a table of contents in your mind, but don't focus too much on the implementation details. I argued at first, but in the end I conceded. The truth was, I didn't need to know everything in the book. In fact, anything I did need to know, I would remember after the first or second time I had to look it up. All that I really needed from my first trip through the book was to know what was possible, not exactly how to do it.
Since that conversation, I've been very happy with the results I've gotten from mentally indexing the concepts instead of memorizing the text. And now the Pragmatic Programmers have made it even easier by offering their books in PDF form. With searchable versions of the books available it's now easier than ever to read a book well enough to know what's available and then search the PDF for the details when you need them.
The technique I'm describing is what DuplexBook tries to offer you by providing the summary and details in different sections of the book. I think DuplexBook is a great idea, but only time will tell if it is effective. A possible issue I see with DuplexBook is that the summary may provide too many or not enough details depending on your personal preference. Truthfully, I end up reading all DuplexBooks cover to cover anyway. I generally like more detail than the summary provides.