Doctoral Program in Computer, Communication and Information Sciences

PhD Annual Report

Candidate: Mauro CherubiniThesis Director: Prof. Pierre Dillenbourg

Lausanne, March 28, 2006

1 Name of the candidate

Mauro Cherubini

2 Probable title of the thesis

Collaborative Annotations of Maps: a Computational Model that IntegratesGeometrical and Semantical Dimensions of Communication.

3 Keywords

i. Computer Supported Collaborative Learning / Work (CSCL / W); ii. Collab-orative Annotations of Maps; iii. Locative Media; iv. Location Based Services;v. Informal Learning; vi. Spatial Cognition; vii. Visual Information Retrieval;viii. Spreading Activation; ix. Spatial Information Retrieval; x. Mobile Infor-mation Retrieval.

4 A precise abstract of the subject being studied

This work targets Collaborative Annotations of a Map in a mobile setting.This is a form of communication that makes explicit usage of the geographi-cal/physical context as referent to the message content. The goal of this studyis to develop a computational support for such communication, defining a modelthat enable to integrate spatial information with the textual information pro-duced through computer-mediated communication. As first step, I will analysedatasets of these particular messages with the aim of understanding their pecu-liarities in comparison with comparable canonical forms. After, I will use this

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information to build a specific information retrieval engine that will support theusers exploration of the information space.

5 Update of the general plan of the thesis

The research plan presented in the thesis’ proposal maintained the stated re-search objectives. However, some technical constraints and advancements, whichhappened during the last year, moved the focus of research to the direction de-tailed afterward. The advancement of the second tool presented on the researchplan, the mobile application for annotation named STAMPS1, brought me toconcentrate on the city scenario sketched on the thesis’ project. Secondarily, Ioperated some choices on the algorithm to be used on the content-side of thesearch engine. Some pre-experiments brought me to explore the possibility toincorporate and extend a Spreading Activation model for information retrieval[Crestani, 1997]. I plan to run specific experiments to confirm our initial findings(Experiment 2 on figure 4).

I expect the first experiments to take place in this semester. The current planis to recruit 40 subjects and ask them to use the application during a 6 monthsperiod. During this timeframe different information retrieval technologies willbe activated allowing us to register any emerging difference of usage of the tool(Experiment 1 on figure 4).

In parallel, I signed a collaboration with an English firm, named Proboscis,that developed and tested a similar application called Urban Tapestries2. Iobtained access to the datased collected by this company during the field trialwhich took place in London, last year. This will allow me to compare our resultswith similar messages taken in a different context, increasing the scientific valueof any produced result.

6 Abstract of the results obtained during thepast year with a list of publications and tech-nical reports

The thesis project was presented in several meetings: the CAIF workshop (Col-laborative Artefact Supporting Collaboration) a three-days workshop that wasorganized in Chateau–d’Oex in Switzerland [Cherubini, 2005b]. More recentlythe project was presented at the Kailedoscope workshop organised in Oulu,Finland [Cherubini, 2005a].

From the submission of the research plan (the 13th of June 2005) differentdeliverables have been completed. Initially the ShoutSpace client was testedinternally (see figure 1).

During the fall 2005 I compiled a literature review on the subjects of visualinformation retrieval [Au et al., 2000] and information retrieval in a mobile con-text, which was presented internally on the 10th of November 2005. During thediscussion, I presented a possible contribution for the thesis, namely the incor-poration of a geometrical routing of energy in a spreading activation model for

1See the website: craftsrv1.epfl.ch/research/stamps/2See the website: urbantapestries.net/

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Figure 1: ShoutSpace interface

information retrieval [Crestani, 1997]. This led me to promote and develop anexperimental framework that could be used to compare semantic retrieval en-gines. Figure 2 represents the experimental tool used in the tests. A publicationon this theme is in preparation.

During the last semester I completed the development of the mobile versionof the application, STAMPS. On figure 3 is possible to see the interaction flowof an user that is posting a message at a certain place.

7 Abstract of the work done from the beginningof the project

I have been testing different approaches to investigate the thesis’ idea: howspace can influence communication. I started this project trying to find a wayfor architecture students to change their approach of study towards urban plan-ning. In this context, we developed a proposal aiming to provide a computa-tional device to collaboratively build their notes on the city [Cherubini, 2003].At the end of this period I elaborated a vision on how this technology couldmove to a broader audience to support citizenry while exploring their city space[Cherubini and Nova, 2004].

After, I decided to slightly change the focus of my work, concentrating onquestions which are more of interests for the CSCL community: the inferenceand grounding processes. The approach chosen, focused on the small group andon the cognitive processes happening between the members while jointly solvingor elaborating tasks [Cherubini, 2004]. Furthermore, my last work focused onthe grounding process as a key element to understand collaborative knowledge

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Figure 2: Visual Information Retrieval Experiment interface

construction [Cherubini and van der Pol, 2005].All the different elements described in this section and in the precedent are

schematised in figure 4, which shows the thesis’ plan with an updated timelineof development.

8 Plan of the work to be achieved during theyear ahead

Three phases will be required to achieve the thesis’ goals: (a) the observation ofpeople communicating using the designed application; (b) the refinement of theretrieval engine that could sustain this kind of communication; (c) the validationof this model through a second experimental phase.

(a) Phase I: The observation of communication. This part of researchshould last 6 months: an experimental group of users will be gathered for pro-viding experimental data to the framework. The results of this enquiry will beanalysed to serve the development of the second phase. The data collected dur-ing this phase will be compared with those collected with alternative systemslike Urban Tapestries (Q1 on figure 4).

(c) Phase II: The computational algorithm. The observation of phase-I will provide some clues on the nature of this kind of spatial communicationlike the connection of semantic and geometry of the messages. Together withside experiments on the semantic retrieval engines (Experiment 2 on figure 4),this will suggest a possible mechanism to sustain this kind of communication

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Figure 3: Interaction flow of the STAMPS interface

that will be implemented in this phase.(c) Phase III: The verification. Finally, during the last phase the re-

trieval system implemented during the second phase will be evaluated with twoexperimental group of users. The phase three might interleave during the 6months of phase I (Experiment 1 continued on figure 4).

8.1 How I plan to answer the research question

In this research, I will develop modelling schemas that enable to integrate spa-tial information, as embedded in maps, with the textual information producedthrough computer-mediated communication. This integration will be investi-gated through the development of a specific search engine that combines thesetwo sources of information.

Q1. What is the mapping between the geographical, thesemantic and the social structure of a body of localisedtext-based asynchronous messages?

To answer this question I propose to cluster the messages treating them asgeometrical entities at first and then as semantic entities. The mapping between

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the two different grouping will define a distortion between the two differentaspect of the spatial communication. Additionally several other markers can beused to identify differences of this kind of communication from a comparableform as newsgroups messaging (i.e., dispersion of the messages, structure form,number of links per node, specific pointer words frequency, etc.).

Q2. Does the geographical structure of the message set facilitate theclustering of messages into meaningful patterns?

The messages datasets contain information on the message’s author, time,and threading. Using this information is possible to construct different mapsusing primarily one of these components at a time. Then differences between theobtained maps can be measured with the specific aim of finding map invariants.

Q3. Will a search engine based on space-interaction patterns sup-port search processes that are less formal than keyword-based searchprocess?

To answer this question we will use the experimental setup described in thethesis proposal. Two group of users of the annotation tool will be exposed todifferent search engines: a control group using a plain keyword-matching engine;an experimental group using an advanced search engine which will relate themessages geometrical dimension with the semantical dimension. The observeddifferences of usage of the tool by the two different groups will provide clues onthe question.

9 Estimated achievement date

September / October 2007

10 Signatures

Mauro Cherubini Prof. Pierre DillenbourgCandidate Thesis’ director20th of March 2006

References

[Au et al., 2000] Au, P., Carey, M., Sewraz, S., Guo, Y., and Ruger, S. M.(2000). New paradigms in information visualization. In Proceeding of SI-GIR’2000, pages 307–309, Athens, Greece. ACM Press. Available from:http://km.doc.ic.ac.uk/www-pub/npiv-sigir2000.pdf.

[Cherubini, 2003] Cherubini, M. (2003). Maptribe proposal. Tech Report 3,CRAFT, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzer-land. Available from: http://www.i-cherubini.it/mauro/projects/MapTribe/.

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[Cherubini, 2004] Cherubini, M. (2004). A collaborative ontology for ‘spa-tialised communication’. In Position paper for the workshop “Potential ofCognitive Semantics for Ontologies”, part of FOIS2004, Torino, Italy. Avail-able from: http://www.i-cherubini.it/mauro/publications/FOIS2004WorkshopPositionPaper CherubiniExtAbs.pdf.

[Cherubini, 2005a] Cherubini, M. (2005a). Stamps, a system for georeferrencedmessaging. In Presentation at the workshop Multiple Technologies and Toolsfor Supporting CSCL: A step further. 21-23 November, Oulu, Finland. Kalei-doscope Network of Excellence.

[Cherubini, 2005b] Cherubini, M. (2005b). A system for tagging messages,post-inferential semantics. In Presentation at the workshop CAIF (Collabora-tive Artefacts Supporting Collaboration). June, Chateau d’Oex, Switzerland.Ecole Polytechnique Federale de Lausanne.

[Cherubini and Nova, 2004] Cherubini, M. and Nova, N. (2004). To liveor to master the city: the citizen dilemma: Some reflections onurban spaces fruition and on the possibility of change one’s atti-tude. Imago Urbis, Universitas de Quilmes, Buenos Aires, Argentina,(2). Available from: http://www.i-cherubini.it/mauro/publications/Cherubini Live or Master 21apr04.pdf.

[Cherubini and van der Pol, 2005] Cherubini, M. and van der Pol, J. (2005).Grounding is not shared understanding: Distinguishing grounding atan utterance and knowledge level. In CONTEXT’05, the Fifth Inter-national and Interdisciplinary Conference on Modeling and Using Con-text, Paris, France. Available from: http://www.i-cherubini.it/mauro/publications/Cherubini vanderPol CONTEXT05 dc.pdf.

[Crestani, 1997] Crestani, F. (1997). Application of spreading ac-tivation techniques in information retrieval. Artificial Intelli-gence Review, 11(6):453–482. Available from: http://www.springerlink.com/(o0ccgl550sriscezu3ugap45)/app/home/contribution.asp?referrer=parent&backto=issue,2,2;journal,49,50;linkingpublicationresults,1:100240,1.

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Figure 4: Thesis plan with updated timeline

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