Contextual Direct Relevance

Intuition

• The ratio of symbols shared to symbols used
• Sharing common symbols is not so relevant

Definition

• The contextual intersection Π_S between Fa and Fc in the context of the set S is

                             |{f:f∈S,s∈sym(f)}|
  ∑                    ( 1 - ------------------- )
  s∈(sym(Fa)∩sym(Fb))               |S| 

• The contextual direct relevance between Fa and Fc in the context of the set S is

  |sym(Fa) ΠS sym(Fc)|
  --------------------
  |sym(Fa) ∪ sym(Fc)| 

• The directed contextual direct relevance from Fa to Fc in the context of the set S is

  |sym(Fa) ΠS sym(Fc)|
  --------------------
       |sym(Fc)|