Gena, Cristina

English

Institutional Research Information System University of Turin

Leveraging social and semantic components in adaptiveenvironments?Cristina GenaDipartimento di Informatica, Universita` di TorinoCorso Svizzera 185; 10149 Torino, Italycgena@di.unito.it1 AbstractIn a Web 3.0 perspective, web sites and portals require design elements that make themexecutable environments (following W.L. Hoschs layering: read-only Web 1.0 - read-write Web 2.0 - read-write-execute Web 3.01). A number of interface and software com-ponents have been implemented for providing such elements, with various appraisalswith respect to their effectiveness in interaction and communication tasks, such as, e.g.,navigation, retrieval, learning.In this paper, I’ll address an innovative element for the design and implementationof Web 3.0 executability in the context of a learning environment: a semantic layer forsupporting tag annotation. We have applied these elements in the project 150 Digit, aweb portal designed for (primary, middle, and high) school classes to virtually interact(also in a 3D environment) with the exhibitions that celebrate the 150th anniversary ofItaly unity (http://www.150digit.it). In particular, I’ll describe the ontology-based rec-ommendation strategies for tags incorporated in 150 Digit and discuss the results of anevaluation carried out in a real setting. 150 Digit displays the exhibits and the relateddocuments, such as the curators’ notes, some learning objects created by the classesabout the displayed items, multimedia presentations created by the teachers about 150thanniversary themes, etc. 150 Digit encourages the active participation of the users (stu-dents, teachers, other registered users) in tagging, voting, and commenting the exhibitsand in creating, uploading, and tagging new contents. Tag recommendations supportthe active participation of the users helping the user to select relevant tags for both anexhibit and a newly uploaded material. Tag recommendations aim at introducing newconnections over the site contents, and expanding the semantic categorization of the ex-hibitions from the categories provided by the curators to the semantics emerging fromthe users tags thus supporting from a 2.0 to a 3.0 perspective.As shown by [2], semantic tools that exploit taxonomic knowledge already providean external grounding for the relations among tags that emerge in a folksonomy, open-ing the way to the integration of these two sources of information. The semantic layerof 150 Digit consists of a categorization of the exhibits (also applied to user-contributed? I would like to thanks my colleagues, Rossana Damiano and Vincenzo Lombardo, whichworked with me during the overall steps of this project.1 http://www.britannica.com/blogs/2007/07/web-30-the-dreamer-of-the-vine/2 C. Genacontent) through semantic labels that integrate the bottom-up, folksonomic representa-tion of the site contents with their top-down, institutional categorization, thus makingthe curatorial knowledge available to the learning community and accessible throughseveral exploration paths built upon the annotations of classes. In 150 Digit, the well-known vocabulary problem is addressed through an expansion along the meaning rela-tions encoded in MultiWordnet, given the constraints provided by the semantic labelsattached to the exhibits. The semantic component relies on a light ontology, the Word-Net Domains [1], a taxonomy of domain labels originally developed to add semanticinformation to the meaning of terms in WordNet. While most ontologies require theexpert knowledge to understand their structure (consider, for example, the foundationalontologies such as SUMO or DOLCE), the WordNet Domains lend themselves to nonexpert users, providing an off-the-shelf, portable layer on the top of which semanticrecommendation tools can be easily built. The content recommender also follows thisapproach, by integrating social filtering techniques with the semantic knowledge en-coded in tags.During a few months, students and teachers have been visiting the largest (and per-manent) exhibition (Fare gli italiani Making Italians), and then attending a set of posthoc laboratories wherein they are required to interact with 150 Digit portal. These lab-oratories have constituted the basis for a thorough evaluation of the system with a two-fold goal: on the one side, to assess the advantage of Web 3.0 approach over Web 2.0approach in recommendation, on the other, to assess its suitability for learning applica-tions. During the lab sessions, the students were required to analyze the items relatedto the exhibits and to create and upload new materials, adding tags while doing boththese operations; the students, randomly, either interacted with a modified version ofthe system - with the tag and content recommendation systems disabled - or with theregular one, thus receiving tag and content recommendations. In the talk, I’ll present theresults, evaluating the impact of our approach on the following aspects: the acceptanceand the accuracy of recommended tags, the tagging activity of users, the quantity andthe typology of the inserted tags, and the semantics they convey. The latter point impliesan analysis of the collaborative content structure that emerges from the tag sets gener-ated by the two versions of the system. This structure relies on MultiWordnet to capturethe semantic relationship over tags and is compared with the semantic (MultiWordnet-based) relationship encoded into the system. In order to gain evidence for our approach,we also assess its benefits for the search function, by comparing the search results onthe two sets of annotated data (with and without the semantic recommender).References1. Bentivogli, L., Pianta, E., Girardi, C.: Multiwordnet: developing an aligned multilingualdatabase. In: First International Conference on Global WordNet, Mysore, India (2002)2. Markines, B., Cattuto, C., Menczer, F., Benz, D., Hotho, A., Stumme, G.: Evaluating similaritymeasures for emergent semantics of social tagging. In: Proceedings of the 18th internationalconference on World wide web, April. pp. 20–24. Citeseer (2009)

Leveraging social and semantic components in adaptive environments

https://iris.unito.it/bitstream/2318/115865/1/sasweb2012_invitedtalk_1.pdf

Leveraging social and semantic components in adaptive environments

Abstract

Similar works

Full text

Available Versions

Institutional Research Information System University of Turin