To conduct searches, most users type one, two, or three words into the search engine. That's very little info from which to dredge up the answer to somebody's problem out of the billions of pages on the Web. But in our testing, large external search engines such as Google, Yahoo!, and MSN Search succeeded 56 percent of the time, which is pretty good. (These "big three" are sometimes referred to with the acronym GYM.) While most users in our study used one of the big three, we had a few users who preferred other search engines, mainly America Online (AOL) Search.
Tip: How to Know If You Need Search
As a rule of thumb, you can probably do without Search if you have less than 100 pages on your site. Sites with between 100 and 1,000 pages usually need just a fairly simple search engine. It's once you get into the thousands of pages that you really need to invest in making Search the best it can be.
Another way of assessing whether your site needs Search is to look at your list of products, press releases, or any other important content categories. If these lists are so short that users can easily scan them on a single page, you probably don't need a search function. (The main exception would be if you have so many different content categories that there are too many lists to scan, which makes it likely that people will get lost.)
When people used internal search engines to search just the site they were on, their success rate was only 33 percent. Site Search should not be so much poorer than Web Search. In fact, there are many reasons why it should be better:
There is obviously a much smaller set of pages to be considered on a single site than on the entire Web.
Within a single Web site, you have a much better handle on the user's intent. For example, you would know whether the word "jaguars" referred to cars, animals, a football team, or a rockabilly band depending on the Web site that was being searched. Yahoo! has no such luxury.
You know what documents are the most important on your site, so you can prioritize the hits based on their intrinsic value instead by the imputed value external search engines have to use.
Conversely, you know which documents are old or obsolete, so you can give them a lower placement by default.
You potentially have even more access to meta-data than big search engines do, which allows your Search software to know much more about your documents and their relationships than an external engine could discover by spidering the site.
You have a controlled vocabulary, so you know the synonyms, misspellings, and other variants that might lead you to return a document even if the user's exact query words don't appear in the text.
You can trust your own information, so you can use optimal, human-written summaries of each page instead of the computer-generated snippets that many search engines show because they don't trust Web sites to describe themselves honestly.
You don't have to contend with spammers or sites that try to manipulate the search engine to achieve a higher ranking than they deserve.
Three Simple Steps to Better Search
Buy better Search software. It's well worth the investment, considering how much users rely on Search. Also, take the time to tweak the settings to optimize retrieval on your site.
Design the Search interface and the search engine results page (SERP) according to the usability guidelines in this chapter.
Improve the pages on your site so that they work better with Search software. Write page titles that are easy for users to scan on the SERP. Write page summaries that succinctly describe what each page is about to help users decide which listing to click. Use the Search Engine Optimization (SEO) principles in the last section of this chapter to help the software do a better job.