Search

The World Wide Web offers the chance to search a huge range of documents and databases but most of the search engines focus on one area, web pages. If you want to search anything else, you need to know and understand special search tools and techniques.

If you want to search for images, try the altavista.com facility. I tested the altavista image search many times and few searches bring back relevant results. The software does not know what is in an image so makes a guess based on text surrounding the image, a technique that works for a small percentage of images.

There is a huge range of information sources available across the Internet but not all the information is available as web pages and some sources require special access facilities. The Z39.50 protocol gives you access to a huge range of special databases, many in libraries, that contain content, or index content, from historical paper based sources. If you want to search old newspapers, search the Z39.50 sources using PHP's YAZ functions.

Chapter 18 Search contains the following sections.

   In Depth
      Searching Search Engines
         LDAP
      Z39.50
      YAZ
         Installing YAZ
         Data Sources
         Testing
         RPN
      Searching with YAZ
         Unsupported Search
         YAZ Functions
      Database-Based Searches
         Keep Data Original
         Keep Data Flexible
         Keep Searches Flexible
         Classify Data
         Reduce but Do Not Remove
         Use Free Text Association
         Build a Big Index

   Immediate Solutions
      Searching One Server
         search()
         array_display()
         State Library of South Australia
         Bell Labs
      Searching Multiple Servers
         Data Source
         The Search Parameters
         search()
         array_display()
         Testing the Search
         The Results
      Searching google.com
         The Form
         The Raw Results
         The Results Edited
         The Results Displayed
      Indexing Data