A central issue in knowledge representation is retrieval: it is unlikely that the current problem will exactly match the stored form of knowledge. How can we tell what part of our knowledge is relevant?
Knowledge:
JAPAN BOUGHT 2,000,000 BARRELS OF OIL FROM IRAN.
Possible Questions:
DID JAPAN BUY 2,000,000 BARRELS OF OIL FROM IRAN? DID JAPAN BUY 1,000,000 BARRELS OF OIL FROM IRAN? DID JAPAN BUY OIL FROM IRAN? TO WHOM DID IRAN SELL OIL? WHAT ARE MAJOR JAPANESE IMPORTS? WHAT US ALLIES WOULD BE CRITICALLY AFFECTED BY BLOCKAGE OF MIDDLE EAST OIL SHIPMENTS?