Whether you are responsible for a public site, e-commerce venture or a private intranet, if your site has a large amount of Web-based information, you need to make sure your on-site search is optimized. Market research points to a rapid rise in the use of on-site search in recent years. While roughly half of Web visitors to any site search in order to find information, this number is expected to grow as Web users continue to gain proficiency.

A user-centered search is a satisfying experience for all involved: Users find what they’re looking for, and your organization meets its goals of getting users what they need — with better business metrics to show for it. Case studies by various e-commerce and enterprise search-tool vendors indicate that improving search features can translate into better conversion rates, improved customer satisfaction ratings and higher transaction volume on a site, among other benefits.

But that’s the best-case scenario. In reality, organizations frequently roll out their sites with out-of-the-box search tools and then neglect to refine them to reflect the actual behavior. Or, worse, the search has been implemented by simply replicating what another (not necessarily identical) site is doing. (I call this the Amazon phenomenon.)

But you need to optimize the search for your site, your content and your users. If you haven’t done this yet, there’s no time like the present to reassess the key elements of your on-site search that affect the user experience; namely, scope, design, results and error handling.

Understanding Scope: How Broad a Net?

What is the breadth of your search? You need to ensure that it’s optimal for your content and usage. Does your search include items in your database as well as Web pages, multimedia files as well as standard documents? Are you including a “search the Web” feature, in addition to your on-site search? You should have a good reason for including this, as such features tend to take users off your site (did you really want to do that?) and are best suited to research, academic or very large information portals, not e-commerce sites.

To ensure you are delivering everything your users are expecting to find on your site, you should investigate what they’re searching for today. An examination of the search query log will help you understand what your site’s users are currently doing. Are they typing in phrases or single words? Are they misspelling your leading product names or brands? This is easy to correct for, but you must know that they are doing it first and how and what they’re misspelling. Some search engines, such as Google Search Appliance, are very good at suggesting corrections.

The devil is in the details here. Are users primarily typing in numbers? That would indicate they’re looking for parts or particular items. You should make sure you are returning meaningful results.

Armed with your analysis, your development team (or search consultants) should fine-tune the search algorithms to enable users to find the results they’re looking for. This will usually mean work on the search dictionary and thesaurus.

Design: Determining the Guidance Level

Search is more than a single field. One key design issue in implementing an on-site search is how much guidance you should provide your users.

You can offer an array of options targeted to your content, as well as to your users and their likely level of knowledge or expertise. Depending on the number of options available, guidance can come in the form of pull-down menus, radio buttons, separate small search areas, or a narrow-your-choice feature such as found on many product search sites.

Does your tool include a natural-language search? Some search tools such as EasyAsk are sophisticated at handling phrases that may be appropriate for customer-oriented organizations or a site’s customer-service sections.

You should also consider advanced search and search tips if your search has enough complexity (if not, it’s OK to leave them out). Advanced searches can involve virtually any aspect of the search algorithm, including the ability to include or exclude a word or phrase, language, geographic region or dates of content publication. A problem with advanced search is that most users don’t bother to use it; they just type and go. Therefore, if the scope of the advanced search is important to your overall search feature, consider how to make it readily apparent—either before the search occurs or on the results page as an option to filter your results.

Maximizing Payoff: Results Display

Next, take a look at the core of any search: your results pages. Taking the user’s perspective, consider the following as to whether your results are cutting the mustard:

• Are an appropriate number of results returned?
• Are the main results relevant to what was typed?
• Are corrections suggested for users’ misspellings?
• Are the results ordered or ranked somehow (and is this ordering structure apparent?)?
• Is the content labeled or indicated (HTML pages vs. PDF documents vs. multimedia?)?
• Is there an easy way to “open and close the valve” and see fewer or more results?

Today’s Web users expect a search results page to have these basic elements. They also expect results to relate to their needs and interests, and if they don’t, they expect to be able to quickly fine-tune results and “re-search.”

One useful element on results pages is the intelligent cross-reference. Whether you’re selling a product or service or just pointing people to the right information, many potential references may not rank as high for the key word but may interest to the user. Don’t overlook this powerful area for enhancing your Web-site results. They won’t annoy the user if they’re labeled correctly.

Error Handling and Messaging

If you’ve done your search-tool optimization properly and tweaked your algorithms for how people are actually entering information, you shouldn’t have a problem with too many null results. Null results aren’t always seen as a negative element of a search design, unless the user continues to get them. There’s nothing worse than getting “no results found” messages on a site where the user knows there is content to be found. You are then forcing users to browse to find the information, and you risk losing them altogether.

Allowing a user to recover from null results is a must on any site, but avoiding null results is even better. The development of a better thesaurus with more cross-references can help in this respect, as most such problems are the result of inadequate dictionary and thesaurus preparation.

Meeting Users’ Expectations

Search results on any site are about meeting user expectations. Web users have learned to search—and search quickly—for virtually anything on the Web. When they come to your site, they’re expecting to find an array of offerings or content based on a few words or a phrase. You can do a better job of satisfying your users if you take the time to see what they’re currently expecting to find on your site and optimizing your search tools to fit their needs.

Enerson is president and founder of Enervision Media, specialists in user-focused research and design. Enervision helps firms of all sizes design or improve the interface of their consumer, B-to-B and enterprise applications, Web sites and intranets. She can be reached at meryl@enervisionmedia.com.