15.1 Some Background on Information Retrieval

• ad-hoc retrival problem
  query $B$KBP$7(B system $B$,4XO"$N$"$k(B document $B$N(B list $B$rJV$9(B task
  • Exact match $\rightarrow$ grep
  • Boolean queries
    $B>&MQ$N8!:w(B software
  • $BC1=c$JC18l$NM-L5$G$O$J$/(B, $BCNE*$J8!:w(B system $B$r9M$($k(B ($B7k2L(B $B$NI=<(=g=x$J$I(B)
    Figure 15.1 $B$K(B altavista $B$NNc(B, $B$3$NCf$N(B query $B$K4XO"$N$J$$(B $B7k2L$r$O$8$a$+$iGS=|$7$?$$(B
• Relevance Feedback
  $B8!:w7k2L$rBPOCE*$JA`:n$G(B, user $B$,5a$a$F$$$k$b$N$K$h$j6a$E$1$k(B
  1$B2sL\$N8!:w$GF@$i$l$?7k2L$+$iE,Ev$K4XO"$N$"$k$b$N$rA*$s$G(B, $B:F8!:w(B
• Text Categorization
• Routing
  $B4pK\E*$K(B ad-hoc $B$HF1$8$@$,(B, $B4XO"EY$K4X$9$k(B traing data $B$,MxMQ$G$-$k(B task
• Filtering
  $BJ#?t$N(B document $B$rJ,N`(B, Routing $B$h$jFq$7$$(B