However, generalized Web searches -- say, for the latest technical developments in the oil industry -- are problematic because each site has its own largely proprietary ontology, Montanari says. "To cover multiple sources within an information domain, you have to define a common semantic model," he notes.

The same issues apply to internal semantic queries, Montanari says. His group had once hoped to create an enterprisewide semantic schema that would "model and map correspondences for everything in our databases and data sets, with no ambiguity anymore," but the company was unable to resolve differences among business domains including oil, gas, R&D, marketing and others.

"Even at the linguistics level, there are issues," he notes. As a result, internal queries tend to remain within a particular business group or specialty.

Standardized ontologies are starting to crop up in industries feeling regulatory and/or customer pressure, such as healthcare and pharmaceuticals. Whether e-commerce companies will rally around a common schema remains to be seen.