When I first learned of Linked Custom Search Engines from Google Co-op, I didn’t really get it. When I got the explanation, I then saw the potential.
Previously, to create a custom search engine, we needed to go into a control panel to give Google a list of sites we want it to show results from. Depending on the topic or purpose of the CSE, this didn’t scale.
With linked CSE, we only need to give Google a page that contains links to sites that we want to show results from. Google then generates a custom search engine with those sites as sources. This is great for themed sites that link to related sites. It helps the user find additional information from other sites that the current site has linked to. For example, a linked CSE at a Mac website will tend to show results from sites that are related to all things Mac.
For my blog, I wanted to create a CSE that would encompass all the sites that I have linked to, either in posts or blog roll. Since I try to link to quality sites, I tend to get good quality, related results. I called my cse, Thu’s Blogosphere. It shows results from my blog and from all the links on my page that lists all posts. As I add links in my posts, the CSE will automatically get new links to add to my CSE. Google was also smart to cache the data so that my cse doesn’t take forever to load up each time due to the hundreds of links I have.
Having a page that lists all blog posts helps increase the coverage of links, as can be seen in the resulting xml file that Google generates on the fly based on the inputted page. The xml file from my blog home page alone doesn’t contain as many urls.
To conceptualize the difference that this makes compared to regular web search, a search for [cat] in my blogosphere will show results about four-legged feline pets. A regular search for [cat] also includes results about the Cats musical, and the company, Caterpillar.
The links page to feed to Google doesn’t need to be like the one I’m using. It was just easier for me to build a page with all of my blog links by showing all my posts. It would be more efficient to show a page that contains only links. I just couldn’t figure out how to do that.