Below are our Yahoo!® search results for "azt and clinical trials".
Click here if you want to open a new browser window to Yahoo!® (http://dir.yahoo.com/). You can also do a "Bookmark" in Netscape® or add it to your "Favorites" in Internet Explorer® if you want to go back to it later.
Let's take a look at the second Web site that was found in our search:

The second Web site that was found in the Yahoo!® search is the NIAID Clinical Trials Factsheet.
Click here if you want to open a new browser window to NIAID Clinical Trials Factsheet. You can also do a "Bookmark" in Netscape® or add it to your "Favorites" in Internet Explorer® if you want to go back to it later: http://www.niaid.nih.gov/factsheets/clintrials.htm).
We're looking for the words "azt" and "clinical trials" on the Factsheet. Look at the screen captures below, or click on the Factsheet link above to follow along "live".
Notice on the screen below that the phrase "clinical trials" appears at the very top of the page and several more times further down in the page:

If we scroll down the screen a bit, we will find the word "azt":

So, this shows you an example of how the LOCATION and FREQUENCY of search words on a Web site impact on search engine results. It also shows, however, why search engine results can be sloppy. The right WORDS appear on the Web site, but that doesn't mean that the words are related to each other, or have the meaning that we want. This is always a potential problem with search engines results.