This short paper investigates how locations in or close to

water masses in topics and documents (e.g. rivers, seas,

oceans) are referred to. For this study, 13 topics from the

GeoCLEF topics 2005-2008 aiming at documents on rivers,

oceans, or sea names were selected and the corresponding

relevant documents retrieved and manually annotated. Results of the geographic annotation indicate that i) topics aiming at locations close to water contain a wide variety of spatial relations (indicated by dierent prepositions), ii)

unnamed locations can be generated on-the-fly by referring

to movable objects (e.g. ships, planes) travelling along a

path, iii) underspecied regions are referenced by proximity

or distance or directional relations. In addition, several

generic expressions (e.g. "in international waters") are frequently used, but refer to different underspecified regions

Leveling, Johannes

English

Crossref

Unnamed locations, underspecified regions, and other linguistic phenomena in geographic annotation of water-based locations

This short paper investigates how locations in or close to
water masses in topics and documents (e.g. rivers, seas,
oceans) are referred to. For this study, 13 topics from the
GeoCLEF topics 2005-2008 aiming at documents on rivers,
oceans, or sea names were selected and the corresponding
relevant documents retrieved and manually annotated. Results of the geographic annotation indicate that i) topics aiming at locations close to water contain a wide variety of spatial relations (indicated by dierent prepositions), ii)
unnamed locations can be generated on-the-fly by referring
to movable objects (e.g. ships, planes) travelling along a
path, iii) underspecied regions are referenced by proximity
or distance or directional relations. In addition, several
generic expressions (e.g. "in international waters") are frequently used, but refer to different underspecified regions

Irish Universities

This short paper investigates how locations in or close to\ud
water masses in topics and documents (e.g. rivers, seas,\ud
oceans) are referred to. For this study, 13 topics from the\ud
GeoCLEF topics 2005-2008 aiming at documents on rivers,\ud
oceans, or sea names were selected and the corresponding\ud
relevant documents retrieved and manually annotated. Results of the geographic annotation indicate that i) topics aiming at locations close to water contain a wide variety of spatial relations (indicated by dierent prepositions), ii)\ud
unnamed locations can be generated on-the-fly by referring\ud
to movable objects (e.g. ships, planes) travelling along a\ud
path, iii) underspecied regions are referenced by proximity\ud
or distance or directional relations. In addition, several\ud
generic expressions (e.g. "in international waters") are frequently used, but refer to different underspecified regions

Name not available

Unnamed Locations, Underspecified Regions, andOther Linguistic Phenomena in GeographicAnnotation of Water-based LocationsJohannes LevelingCentre for Next Generation Localisation (CNGL)Dublin City University, Dublin 9, Irelandjohannes.leveling@computing.dcu.ieABSTRACTThis short paper investigates how locations in or close towater masses in topics and documents (e.g. rivers, seas,oceans) are referred to. For this study, 13 topics from theGeoCLEF topics 2005-2008 aiming at documents on rivers,oceans, or sea names were selected and the correspondingrelevant documents retrieved and manually annotated.Results of the geographic annotation indicate that i) top-ics aiming at locations close to water contain a wide varietyof spatial relations (indicated by different prepositions), ii)unnamed locations can be generated on-the-fly by referringto movable objects (e.g. ships, planes) travelling along apath, iii) underspecified regions are referenced by proxim-ity or distance or directional relations. In addition, severalgeneric expressions (e.g. “in international waters”) are fre-quently used, but refer to different underspecified regions.Categories and Subject DescriptorsH.3.1 [Information Storage and Retrieval]: ContentAnalysis and Indexing—Linguistic processing ; H.3.4 [Infor-mation Storage and Retrieval]: Information Search andRetrieval—Search ProcessKeywordsGIR, Toponyms, Annotation1. INTRODUCTIONEvents and situations described in newspaper articles arereferred to mostly by names of populated places on land.Topics aiming at events happening in or close to water bodies(e.g. rivers, seas, or oceans) are less frequent but more dif-ficult to process in a geographic information retrieval (GIR)system. This short paper investigates how locations in orclose to water masses in topics and documents are typicallyexpressed in natural language..Table 1: Selected GeoCLEF topics.Topic Topic title # Rel.01-GC “Shark Attacks off Australia and Califor-nia”1416-GC “Oil prospecting and ecological problems inSiberia and the Caspian Sea”1521-GC “Sea rescue in North Sea” 2936-GC “Automotive industry around the Sea ofJapan”041-GC “Shipwrecks in the Atlantic Ocean” 447-GC “Champions Cup games near the Mediter-ranean”2450-GC “Cities along the Danube and the Rhine” 1553-GC “Scientific research at east coast ScottishUniversities”63-GC “Water quality along coastlines of theMediterranean Sea”066-GC “Economy at the Bosphorus” 374-GC “Ship traffic around the Portuguese islands” 385-GC “Nuclear tests in the South Pacific” 4391-GC “Forest fires on Spanish islands” 295-GC “American troops in the Persian Gulf” 53In contrast to events on land, events happening in or closeto water masses may be more difficult to describe. Most lo-cations in water are unnamed (except for islands), becausethey are not populated, and there is no deep hierarchicalstructure of water bodies, i.e. no natural subdivisions ex-ist and the typical in-relations cannot be exploited for GIR.Thus, these topics pose a challenge: if complex spatial re-lations are not correctly identified and interpreted, GIR ef-fectiveness will decrease. For instance, a location name ina document may be part of a complex natural language ex-pression to refer to events at a different, distant location.Furthermore, relevant documents may not be found becausethe same place is referred to by different natural languageexpressions.2. TOPICANDDOCUMENTANNOTATIONThirteen topics from the GeoCLEF evaluation campaign2005-2008 were selected [1], where in the topic title or de-scription a sea, river, or ocean is mentioned. The selectedtopic titles and the number of corresponding documents as-sessed as relevant (# Rel.) are shown in Table 1.Note that for most topics, descriptions of events in or closeto water will be relevant. For some topics however, eventson land are also relevant (e.g. 16-GC, 47-GC, 50-GC). InTable 2: Annotation frequencies.Type FrequencyLocation adjectives 1752 23.05%Location nouns 3049 40.11%Metonymic use 1142 15.02%Demonyms (population name) 230 3.03%Unnamed/underspecified locations 1428 18.79%Sum 7601 100.00%one case (GC-63), descriptions of both types may be rele-vant, depending on whether “water quality” refers to drink-ing water or bathing water. For topics GC-85 and GC-95,the highest number of relevant documents has been found(96 out of 205). For two other topics (36-GC and 63-GC),no relevant documents have been found, possibly because ofcomplex spatial relations (i.e. “around” and “along”), whichcan not be easily interpreted by GIR systems.For the thirteen topics, 205 relevant documents from theLA times and Glasgow Herald from 1994 and 1995 have beenassessed as relevant. The average number of relevant docu-ments per topic is 15.8. For comparison, the average numberof relevant documents per topic for the set of all topics ex-cluding the selected topics is 29.9 (2598 relevant documentsfor the remaining 87 GeoCLEF topics). There are severalpossible explanations for this difference: 1) There may bemore relevant documents in the document collection, butthese documents have not been found by the systems partic-ipating at GeoCLEF, have not been included in the pooledset of documents, and thus, have not been assessed for rel-evance. 2) There are no more relevant documents, whichmeans that there could be a bias in articles towards eventson land and/or events happening in maritime locations maybe more difficult to describe in natural language.In the relevant documents (about 940 KB text), geographiclocations have been manually annotated. The following an-notation guidelines were followed for the geographic anno-tation of documents: Location names (toponyms), locationadjectives, and names for people inhabiting a place (de-monyms), are annotated, using the longest possible geo-graphic reference (typically a noun phrase, e.g. “in CampDoha, north of Kuwait City”). Ambiguous names and lo-cation names which are part of organisation or institutionnames are not annotated as locations (e.g. “the carrierGeorge Washington”). Coordinations of locations are an-notated as a single instance, except if different annotationsare required (e.g. “Paris and Berlin” is annotated as a sin-gle instance, but “U.S. troops and forces from Kuwait” isnot). Metonymic use of location names is annotated andverbs or nouns indicating the metonymic use are linked tothe location name (e.g. “Russia (promised) Baghdad to cam-paign”). Underspecified regions and unnamed locations, in-cluding anaphoric references to places are annotated as well(e.g. “there”, “in the region”). Table 2 shows the annotationfrequency.Confirming results from Leveling and Hartrumpf for an-notated German newspaper texts [2], location names in thedocuments are often used in a non-geographic sense and lo-cations can be referred to by means other than proper nouns.Examples of non-literal senses include metonymic use of lo-cation names (e.g. “France said today it would provide emer-gency financial aid to victims”, “Australia and New Zealandwant the issue put high on the agenda”) and location namesas part of other names (e.g. “Ajax Amsterdam”, “EuropeanUnion”). Words other than location names implying a lo-cation include adjectives (e.g. “Alsatian cuisine”, “DanishForeign Minister”) or demonyms (names for people inhabit-ing a place, e.g. “Turkish officials”).Table 3 shows the most frequent geographic relations to-gether with text excerpts from the annotated documents forthe location nouns and unnamed locations (4477 instances).The geographic relations which have been observed typicallycorrespond to prepositions and include proximity (e.g. close,far, near, off ), containment or meronymy (e.g. in, within),paths (e.g. across, along, around, between, through), pathstart points (e.g. from, of, out of ), path end points (e.g.into, to, toward), and other spatial relations (e.g. above,below, beneath, over). In addition, numeric distances andcompass directions (e.g. north, southeast) have also beenfound in the documents. Prepositions which occur onlyrarely (such as atop) have not been included in Table 3.The document annotation shows that in is the most domi-nant relation, but a wide range and number of prepositionscorresponding to spatial paths are also frequently used.Similar to prepositions, verbs may also indicate a path(730 instances of the annotated location nouns and unnamedlocations), including full paths (e.g. “drive/fly from X toY”), path start points (e.g. “leave X”,“depart from X”), pathend points (e.g. “arrive at X”, “land in X”), and stoppinga movement on a path (e.g. “crash/sink/stop at X”). Someverbs are compatible with multiple prepositions (e.g. “evac-uate from/to X”), other verbs do not require prepositions atall (e.g. “reach X”). In summary, geographic relations shouldbe identified considering the preposition preceding the lo-cation together with the associated verb and identificationshould preferably be based on natural language processingtechniques.3. DISCUSSIONThe following observations have been made with respectto natural language description of locations in water. Dueto the nature of the selected topics, locations in or near thewater bodies are referred to mostly in the document parts in-dicating relevance. These locations include oil platforms, oilfields, and moving vessels (e.g. ships, planes, trains). How-ever, the annotated newspaper articles do not exclusivelycover stories about situations and events at sea. Therefore,many mentioned locations are actually located on land. Inparticular, topic 85-GC has the most relevant documents.However, the events described in the documents (nucleartests) incite responses from all over the world, so that mostof the articles are about responses and reactions of countries(which is one reason for the high number of metonymicallyused location names), not mainly about nuclear tests in theSouth Pacific.Locations in the water can be referenced by compass di-rections and distance from a known location (e.g. “about30 miles west of San Francisco’s Golden Gate Bridge”, “22miles from Brae Alpha”, “off the North-west of Scotland”).Some proper nouns for seas are abbreviated if the geographicreference is clear from the document context (e.g. “Caspian”= “Caspian Sea”, “in the Gulf” = “in the Gulf region”).Underspecified regions and unnamed locations are refer-enced as well. In the first case, a large, possibly indeter-minate area or region is referenced (e.g. “in internationalTable 3: Relation types and relations in the annotated documents.Type Relation Document text Frequency SumProximity close “close to Gatwick Airport” 14 165far “far from London” 21near “near Death Valley” 70off “off San Miguel Island” 60Meronymy in “in Alaska” 1192 1909within “within 12 1/2 miles of the Kuwaiti border” 21at “at Clearwater Bay” 332on “on Christmas Island” 364Path across “across the Pacific” 33 171along “along the coast of Northern Europe” 34around “around Loch Lomond” 44between “between the Black and Caspian seas” 21through “through the Maas (Meuse) valley” 39Path start point from “from Salzburg” 327 875of “of Dereham, Norfolk” 465out of “out of Saudi Arabia” 83Path end point into “into the South Atlantic” 65 655to “to Grimsby” 560toward “toward Las Vegas” 30Distance – “40 miles south of the Iraqi border” 84 84Direction – “just north of the Kuwaiti border” 125 125Other above “above the Indian Ocean” 8 87below “below the 32nd Parallel” 8beneath “beneath the South Pacific” 9over “over the North Sea” 62waters off Mururoa atoll”, “in the waters around San MiguelIsland”), in the latter case, a specific location is referenced,but remains underspecified (e.g. “(on the way) from Ab-erdeen to Marathon’s Brae Alpha platform”, “(en route) tothe Red Sea”). These locations typically are places along apath, where the path is either implicitly given (e.g. “fromX to Y”) or defined by artifacts including pipelines, streets,canals, and railways. Unnamed locations can be referredto by paths, often without a start or end point (e.g. “fromAberdeen to Marathon’s Brae Alpha platform”, “to Kuwait”).Rarely, locations are defined by intersections of paths or re-gions (e.g. “where the Amsterdam-Rhine Canal meets theWaal”, “where the Rhine enters the Netherlands”). In afew instances, temporal expressions relate to spatial distance(e.g. “an hour northeast of Zurich”, “before (reaching) theRhine Bridge”).4. CONCLUSION AND FUTUREWORKThe annotation illustrates that documents describing eventslocated in or near water bodies, contain complex naturallanguage descriptions. Due to the effort involved in manualannotation, a sample of documents relevant to land-basedevents has not yet been annotated and a comparison withresults from corresponding documents on land-based eventshas not yet been performed.In some cases, the document parts implying the relevanceof a document for a topic contain references to unnamedlocations, which are typically locations on a path. GIR sys-tems will profit from a deeper analysis of the text which goesbeyond identification and grounding of location names only.As part of the future work, the annotation effort will be usedto produce rules or annotation patterns to improve the accu-racy of location identification. The interpretation of spatialprepositions and verbs in natural language expressions re-ferring to locations will be investigated in more detail.Furthermore, the automatic resolution of anaphoric ref-erences to locations will be investigated. For example, ifcoreferences are resolved and pronouns referring to a loca-tion name are replaced by the location name (instead ofremoving them as stopwords), term frequencies are changedwhich will affect the result ranking of a GIR system.5. ACKNOWLEDGMENTSThis material is based upon works supported by the Sci-ence Foundation Ireland under Grant No. 07/CE/I1142.6. REFERENCES[1] F. Gey, R. Larson, M. Sanderson, H. Joho, andP. Clough. GeoCLEF: the CLEF 2005 Cross-LanguageGeographic Information Retrieval Track. In C. Peters,F. Gey, J. Gonzalo, H. Mu¨ller, G. J. Jones, M. Kluck,B. Magnini, and M. de Rijke, editors, AcessingMultilingual information Repositories: 6th Workshop ofthe Cross-Language Evaluation Forum, CLEF’2005. Revised Selected papers, volume 4022 of LNCS, pages908–919. Springer, 2006.[2] J. Leveling and S. Hartrumpf. On metonymyrecognition for geographic information retrieval.International Journal of Geographical InformationScience, 22(3):289–299, 2008.

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GeoCLEF: the CLEF 2005 Cross-Language Geographic Information Retrieval Track.

On metonymy recognition for geographic information retrieval.

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Unnamed locations, underspecified regions, and other linguistic phenomena in geographic annotation of water-based locations

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