It’s unfortunate when such a simple question calls for a complicated answer, but I’ll try to tackle it.
On the web, almost all attempts to deviate even slightly from the venerable ranked-list paradigm have been resounding flops. More sophisticated interfaces, such as Clusty, receive favorable press coverage, but users don’t vote for them with their virtual feet. And web search users seem reasonably satisfied with their experience.
Conversely, in the enterprise, there is widespread dissatisfaction with enterprise search solutions. A number of my colleagues have said that they installed a Google Search Appliance and “it didn’t work.” (Full disclosure: Google competes with Endeca in the enterprise).
While the GSA does have some significant technical limitations, I don’t think the failures were primarily for technical reasons. Rather, I believe there was a failure of expectations. I believe the problem comes down to the question of whether relevance is subjective.
On the web, we get away with pretending that relevance is objective because there is so much agreement among users–particularly in the restricted class of queries that web search handles well, and that hence constitute the majority of actual searches.
In the enterprise, however, we not only lack the redundant and highly social structure of the web. We also tend to have more sophisticated information needs. Specifically, we tend to ask the kinds of informational queries that web search serves poorly, particularly when there is no Wikipedia page that addresses our needs.
It seems we can go in two directions.
The first is to make enterprise search more like web search by reducing the enterprise search problem to one that is user-independent and does not rely the social generation of enterprise data. Such a problem encompasses such mundane but important tasks as finding documents by title or finding department home pages. The challenges here fundamentally ones of infrastructure, reflecting the heterogeneous content repositories in enterprises and the controls mandated by business processes and regulatory compliance. Solving these problems is no cakewalk, but I think all of the major enterprise search vendors understand the framework for solving them.
The second is to embrace the difference between enterprise knowledge workers and casual web users, and to abandon the quest for an objective relevance measure. Such an approach requires admitting that there is no free lunch–that you can’t just plug in a box and expect it to solve an enterprise’s knowledge management problem. Rather, enterprise workers need to help shape the solution by supplying their proprietary knowledge and information needs. The main challenges for information access vendors are to make this process as painless as possible for enterprises, and to demonstrate the return so that enterprises make the necessary investment.