• Link - Stanford Inference Web

The Inference Web is a Semantic Web based knowledge provenance infrastructure that supports interoperable explanations of sources, assumptions, learned information, and answers as an enabler for trust.

• Provenance - if users (humans and agents) are to use and integrate data from unknown, uncertain, or multiple sources, they need provenance metadata for evaluation.
• Interoperability - more systems are using varied sources and multiple information manipulation engines, thus increasing interoperability requirements.
• Explanation/Justification - if information has been manipulated (i.e., by sound deduction or by heuristic processes), information manipulation trace information should be available.
• Trust - if some sources are more trustworthy than others, trust ratings are desired.