Semantic Mismatches
Information comes from many autonomous sources
Differing viewpoints (by source)
- differing terms for similar items { lorry, truck }
- same terms for dissimilar items trunk(luggage, car)
- differing coverage vehicles (DMV, AIA)
- differing granularity trucks (shipper, manuf.)
- different scope student museum fee, Stanford
Hinders use of information from disjoint sources
- missed linkages loss of information, opportunities
- irrelevant linkages overload on user or application program
Poor precision when merged
ok for web browsing , poor for business