Yahoo and Google are trying to one up each other on whose database contains more pages. Does it really matter? Isn’t relevancy more important? It depends on who your user is.
If most of your queries on search engines return hundreds or thousands of results, then it probably doesn’t matter who has the biggest index. As long as Google and Yahoo get the popular pages, you’ll most likely find what you are looking for. If you get a bunch of results from your search you are probably aren’t looking for a specific document on the web, so it doesn’t matter which page you get as long as it has the information you are after.
Most internet users fall in the above category. I tend to find that many of my searches return less than 20 results and sometimes only 2 or 3 or even 0. For people like me the number of pages searched is much more important. In fact for those types of searches the method used to order the results (determine the relevancy) isn’t really important. With a small number of pages, it is easy to scan through the list and find the most relevant entry.
Today I was working on a piece of equipment and it started giving me a less than helpful error message. I typed the manufacturer (in quotes) and the error message (also in quotes) into Google hoping to find out how to fix my problem. There were zero results. I tried it on Yahoo and got the same thing. After poking around in some forums I was able to find a post that described the problem on a page that was missing from both Yahoo and Google’s databases. The post contained all the phrases that I had searched for it just wasn’t in either of the search engine’s indexes.
Five years ago I taught a community college class about the internet. I used Geocities to put up the tests, class outline, etc. Today I tried search for:
site:geocities "juco internet class"
In Google I get zero results. With Yahoo I get a single result that links to the page I was searching for.
I’m sure that there are other items that I could find with Google that won’t show up in Yahoo. I’m not trying to say one engine is better than the other. The point is that the index size does matter if you are looking for a specific document. If Yahoo decides that they are going to maintain a larger index than Google, then there are going to be pages that can be found in the Yahoo index, but not in Google’s. If you are looking for one of these pages then size is very important.