GraSM
Encyclopedia
GraSM is a method for incorporating the semantic richness of a graph in semantic similarity
measures by selecting disjunctive common ancestors of two concepts. GraSM assumes that two common ancestors are disjunctive if there are independent paths from both ancestors to the concept. In 2011, the authors of GraSM proposed the method DiShIn
with a higher computational efficiency and a more solid management of parallel interpretations.
, platinum
and gold
are considered to be precious metals, and gold
and copper
considered to be coinage metals
. Thus, we have:
metal
/ \
precious coinage
/ | \ / \
palladium platinum gold copper
When calculating the semantic similarity
between platinum and gold,
most topological measures only use their most informative common ancestor, in this case precious.
On the other hand, GraSM takes also in account the following independent paths to metal:
gold -> coinage -> metal
platinum -> precious -> metal
Thus, GraSM defines the similarity between platinum and gold proportional to the average of the information content
of their common disjunctive ancestors: metal and precious; and the similarity between platinum and palladium only proportional to the information content
of precious, since there are no independent paths from them to metal.
This means that for GraSM palladium and platinum are more similar than
platinum and gold, since gold can have another interpretation.
Semantic similarity
Semantic similarity or semantic relatedness is a concept whereby a set of documents or terms within term lists are assigned a metric based on the likeness of their meaning / semantic content....
measures by selecting disjunctive common ancestors of two concepts. GraSM assumes that two common ancestors are disjunctive if there are independent paths from both ancestors to the concept. In 2011, the authors of GraSM proposed the method DiShIn
DiShIn
DiShIn is a method for exploitation of multiple inheritance when calculating the shared information content between two ontology concepts being compared by node-based semantic similarity measures...
with a higher computational efficiency and a more solid management of parallel interpretations.
Example
For example, palladiumPalladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
, platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
are considered to be precious metals, and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
and copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
considered to be coinage metals
Coinage metals
The coinage metals comprise, at minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins. The term is not perfectly defined, however, since a number of metals have been used to make "demonstration coins" which have never been used to...
. Thus, we have:
metal
/ \
precious coinage
/ | \ / \
palladium platinum gold copper
When calculating the semantic similarity
Semantic similarity
Semantic similarity or semantic relatedness is a concept whereby a set of documents or terms within term lists are assigned a metric based on the likeness of their meaning / semantic content....
between platinum and gold,
most topological measures only use their most informative common ancestor, in this case precious.
On the other hand, GraSM takes also in account the following independent paths to metal:
gold -> coinage -> metal
platinum -> precious -> metal
Thus, GraSM defines the similarity between platinum and gold proportional to the average of the information content
Information content
The term information content is used to refer the meaning of information as opposed to the form or carrier of the information. For example, the meaning that is conveyed in an expression or document, which can be distinguished from the sounds or symbols or codes and carrier that physically form the...
of their common disjunctive ancestors: metal and precious; and the similarity between platinum and palladium only proportional to the information content
Information content
The term information content is used to refer the meaning of information as opposed to the form or carrier of the information. For example, the meaning that is conveyed in an expression or document, which can be distinguished from the sounds or symbols or codes and carrier that physically form the...
of precious, since there are no independent paths from them to metal.
This means that for GraSM palladium and platinum are more similar than
platinum and gold, since gold can have another interpretation.