Human-Computer Interaction 3e Dix, Finlay, Abowd, Beale
Getting any product used is all about designing value - if users don't get value from it why should they use it!
When we were prpducing the second edition of our HCi book we wanted to create a supporting web site and trying to decide what to put there. Clearly we could put all the teaching materials we already had: OHPs, worked exercises, etc. However, we wanted something a little extra.
One option was to put the full electronic text online. However at that time publishers were a little wary of making electronic text available. Also having the elctronic text online might give value to those without the book, but on its own wouldn't add value for those who already had the book.
This made us consider the advantages of an electronic copy over a paper copy. One advantage of electronic copy is that it is possible to search it. So this lead to another idea, to have the electronic copy on the server, but not actually readable. The site could then have a search facility that told you what page to look on for any words. This would have value if you owned the book, but wouldn;t be very useful for people who haven't bought it.
N.B. note that searching for keywords in a book is not the same as using an index. First and index has to be quite selective - otherwise it would be as big as the whole book! . So, it may be that the terms you want to look for have not been included in the index. However, index terms are chosen carefully and may refer to parts of the books that don't mention the exact words exactly, but may be references to the ideas or concepts, So the index may give infornation that a keyword search misses. that is the index and keyword searches are complementary methods.
The actual search works as follows. You enter keywords to be searched for as you would with a web search engine (see figure 1).
Figure 1. search window
When you hit the submit button, the system returns the paragraphs in the book that contain the words toigether with the chapter and page numbers of the paragraph (see figure 2). That is, it behaves very like a web search but with paragraphs rather than web pages..
Figure 2. search results
Imagine you have the book already. When you want to find anything in the book you can use the search page. It tells you where to look in the book with enough context to let you know which reference is the most appropriate.
If, on the other hanbd you don;t use the book, the search gives some information about the terms, a bit like an online encycopedia of HCI. So it is still worth bookmarking.
However, if you don't have the book, everytime you use the search you see references to where in the book you would learn more - it says 'buy me' every time!
Notice you get value if you don't have the book but use the web site and even more value if you have both!
Alan Dix, 2001