Geographic reference analysis for geographic document querying

F.Bilhaut , T.Charnois, P.Enjalbert & Y.Mathet

{bilhaut, charnois, enjalbert, mathet}@info.unicaen.fr

GREYC, CNRS UMR 6072

University of Caen

The "GéoSem" project

• Passage extraction from geographical documents

• From a query to a ranked set of passages

• Queries are concerned with :- time

- phenomenon

- space

Excerpt from "Hérin" corpus

From 1965 to 1985, the number of high-school students has increased by

70%, but at different rythms and intensities depending on academies and

departments. Lower in South-West and Massif Central, moderate in

Brittany and Paris, the rise has been considerable in Mid-West and Alsace.

[…] Also occurs the schooling duration increase which was more important

in departments where, in the middle of the 60's, study continuation after

primary school was far from beeing systematic.

Excerpt from "Hérin" corpus

From 1965 to 1985, the number of high-school students has increased by

70%, but at different rythms and intensities depending on academies and

departments. Lower in South-West and Massif Central, moderate in

Brittany and Paris, the rise has been considerable in Mid-West and Alsace.

[…] Also occurs the schooling duration increase which was more important

in departments where, in the middle of the 60's, study continuation after

primary school was far from beeing systematic.

Time

Excerpt from "Hérin" corpus

From 1965 to 1985, the number of high-school students has increased by

70%, but at different rythms and intensities depending on academies and

departments. Lower in South-West and Massif Central, moderate in

Brittany and Paris, the rise has been considerable in Mid-West and Alsace.

[…] Also occurs the schooling duration increase which was more important

in departments where, in the middle of the 60's, study continuation after

primary school was far from beeing systematic.

Time Phenomenon

Excerpt from "Hérin" corpus

From 1965 to 1985, the number of high-school students has increased by

70%, but at different rythms and intensities depending on academies and

departments. Lower in South-West and Massif Central, moderate in

Brittany and Paris, the rise has been considerable in Mid-West and Alsace.

[…] Also occurs the schooling duration increase which was more important

in departments where, in the middle of the 60's, study continuation after

primary school was far from beeing systematic.

Time Phenomenon Space

Queries

• Which passages address educational difficulties in west of France in the 50's ?

• Which passages address variations of the number of pupils in rural areas ?

• Which passages address Calvados district?

Queries

• Which passages address educational difficulties in west of France in the 50's?

• Which passages address variations of the number of pupils in Paris area?

• Which passages address Calvados district?

Some Signifiant Spatial Expressions

Paris

in north of France

from south of Loire

Some seabord towns

The quarter of

The districts in north of France

Fifteen

All

Some seabord towns of Normandy

The most rural districts situated from south of Loire

The type "zone"a georeferenced area anchored in a named place

Paris

in north of France

Normandy

From Normandy to Alsace

from south of Loire

The ‘LocGeo’ type

Quant Type Zone qualification administrative Position named geo. entity

The quarter of / districts in north of France

Fifteen / All /

Some seabord towns of Normandy

The most rural districts situated from south of Loire

Some seabord towns

The canonical form:

[quantification]+[type]+[zone]

The ‘LocGeo’ type

Quant Type Zone qualification administrative Position named geo. entity

The quarter of / districts in north of France

Fifteen / All /

Some seabord towns of Normandy

The most rural districts situated from south of Loire

Some seabord towns

quant

type

zone

Semantic Representation« Paris »

zone: loc: internal

egn:

coord:

ty_zone: town

nom: Paris

Long: 5.733333

Lat: 45.633333

Semantic Representation« Some seabord towns in north of Normandy »

locgeo:

quant:

type:

zone:

type: relative

ty_zone: town

geo: seabord

nom: Normandy

ty_zone: region

loc: internal

position: north

egn:

Implementation and (first) Results

A tokenisation and a morphological analysis

A DCG to perform altogether syntactic and semantic analysis• the grammar contains 160 rules• an internal lexical base of 200 entries• a gazetteer of 100000 named places (France)

9OO expressions recognised and analysed from a geographical corpus (200 text pages)

Good results but a precise and quantitative evaluation to be done

Semantic matching : Why ?

a query

corpora

Tex

t AT

ext B

[…] the northern half of France […]

[…] the south of a Bordeaux-Genève line […]

"Which passages address Paris ?"

[…] In Paris and Toulouse […]

[…] In Ile de France region […]

1

3

2

Semantic matching : How ?

• Spatial compatibility : Is the zone denoted by the passage spatially compatible

with the one of the query? (is there, at least, an intersection?)

• Relevance degree : if this zone is compatible, how relevant is it w.r.t.the

query?- probability- granularity

Compatibility computation

• Q1) Which passages address Paris ?

• P1) […] the capital city […]

• P2) […] big cities in France.

• P3) […] the northern half of France […]

• P4) […] South of a Bordeaux-Genève line.

YES

YES

YES

NO

gazetteer

gazetteer + computation

gis+

com

puta

tion

"the northern half of France"

"the south of a Bordeaux-Genève line"

Relevance degree (1)Quantification

Query= "Calvados" (french district)

P1= "The quarter of districts in north of France"

P2= "All districts in north of France"

P3= "Some districts in north of France"

P4= "Fifteen districts in north of France"

r=25%

r=100%

r=i/n=5/52=9.6%

r=i/n=15/52=29%

GIS

GIS

1

2

4

3rank

Relevance degree (2)Granularity

"Basse Normandie"

"Calvados"

 ’the northern half of France’

"Caen"

countryregiondistrictcity

"zone"

locgeo(locgeo:(det:Det..type:Type..Zone)) --> #prep, det(Det), type(Type), zone(Zone).

det(Sem) --> [X],{lexique(X,[X|R],det,Sem)}.

type(X) --> typeQualif(X).type(ty_zone:N) --> nomtype(N).

typeQualif(ty_zone:N..Q) --> option, nomtype(N), #prep, qualif(Q).

nomtype(Sem) --> [X], {lexique(X,[X|R],nom,Sem)}.

zone(X)--> egn(X).

egn(egn:(ty_zone:T..nom:Y..coord:C)) --> --> ls_lexiconExtDCG(np, type_sem:egn..type_zone:T..nom:Y..coord:C ).

egn(egn:(ty_zone:T..nom:Y)) --> [X],{lexique(X,[X|R],np, type_sem:egn..type_zone:T..nom:Y)}.

 

lexique(quelque,[quelque],det,type_sem:relatif..type:relatif_qualifie..nb:'qualitatif:faible').

lexique(tout,[tout,le],det,type_sem:exhaustif).

lexique(région,[région],nom,type_sem:zone(administrative)..nom_zone:région).

lexique(ville,[ville],nom,type_sem:zone(administrative)..nom_zone:ville).

Lexique('Bretagne',['Bretagne'],np,type_sem:egn..type_zone:région..nom:'Bretagne').