Collaborative tagging as a tripartite network

We describe online collaborative communities by tripartite networks, the nodes being persons, items and tags. We introduce projection methods in order to uncover the structures of the networks, i.e. communities of users, genre families... To do so, we focus on the correlations between the nodes, depending on their profiles, and use percolation techniques that consist in removing less correlated links and observing the shaping of disconnected islands. The structuring of the network is visualised by using a tree representation. The notion of diversity in the system is also discussed

Merging semantic and participative approaches for organising teachers' documents

International audienceCommunities of teachers need tools to gather and organise educational resources scattered over the Web. As current generic search engines are insufficient to deal with contexts, these tools must rely on human annotations. First, we compare the Semantic Web and the Participative Web (2.0) approaches to annotate resources and we argue for the need to merge them. Secondly, we propose a social bookmarking tool merging the flexibility of tags with basic inference processes attached to ontologies. Thus we define the concept of structurable tags which are tags that can be linked through relations while keeping their spontaneous, on-the-fly and aggregative properties

Comparing the hierarchy of keywords in on-line news portals

The tagging of on-line content with informative keywords is a widespread phenomenon from scientific article repositories through blogs to on-line news portals. In most of the cases, the tags on a given item are free words chosen by the authors independently. Therefore, relations among keywords in a collection of news items is unknown. However, in most cases the topics and concepts described by these keywords are forming a latent hierarchy, with the more general topics and categories at the top, and more specialised ones at the bottom. Here we apply a recent, cooccurrence-based tag hierarchy extraction method to sets of keywords obtained from four different on-line news portals. The resulting hierarchies show substantial differences not just in the topics rendered as important (being at the top of the hierarchy) or of less interest (categorised low in the hierarchy), but also in the underlying network structure. This reveals discrepancies between the plausible keyword association frameworks in the studied news portals

Semantic Web gets into collaborative tagging

Collaborative tagging is a new content sharing and organization trend, mainly diffused over the Web, which has attracted growing attention during the last years. It refers to the process by which many users add metadata in the form of keywords to shared content. Today many different collaborative tagging systems are available on the Web, enabling users to add descriptive keywords to different types of Internet resources (web pages, photos, videos, etc.). The great number of advantages offered by the availability of collaboratively tagged resources in terms of their organization and shared information is underlined by their growing adoption, also in non-technical communities of users. In spite of this, analyzing the current structure and usage patterns of collaborative tagging systems, we can discover many important aspects which still need to be improved so as to bring tagging systems to their full potential. In particular, problems related to synonymy, polysemy, different lexical forms, different spellings and misspelling errors, but also the lack of accurancy caused by different levels of precision and distinct kinds of tag-to-resource association represent a great limit, causing inconsistencies among the terms used in the tagging process and thus reducing the efficiency of content search and the effectiveness of the tag space structuring and organization. This kind of problems is mainly caused by the lack of semantic information inclusion in the tagging process. Considering the increasing attention focused on the Semantic Web, we propose a new model of tagging system, based on semantic keywords. We let the users easily define the meaning of their tags, referencing some sort of social ontology. As social ontology we explore the adequacy of the support offered by the entries of Wikipedia andWordNet. Finally we present SemKey, a tool that allows users to tag in a semantic context, providing an evaluation of the system proposed in comparison with classical tagging tools

Undergraduate students: interactive, online experiences and ePortfolio development

Results of a previous study by the authors into the perceived value and potential of ePortfolios to assist undergraduate students indicated that technology was an important aspect of their everyday lives. It was also felt it to be beneficial to their learning. A large percentage of students were found to be using digital techniques to store evidence of their learning, and were also using interactive, online tools in their learning activities. There was, however, little reported structured use of ePortfolio development in their learning. Students acknowledged they were discovering for themselves the value of online technologies in learning. This paper focuses on student skills and experiences of online tools on entry to university, and considers their experience of ePortfolio development using the Wordpress personal publishing platform. Results indicate that students’ skill level of online, interactive tools was high and wide-ranging. Although previous experience of using these tools was unstructured and informal, ePortfolio creation was found to be an engaging, relevant and worthwhile activity. The ePortfolio development exercise also provided an experiential learning experience, and had a positive effect on students’ attitudes to learning

Metadata enrichment for digital heritage: users as co-creators

This paper espouses the concept of metadata enrichment through an expert and user-focused approach to metadata creation and management. To this end, it is argued the Web 2.0 paradigm enables users to be proactive metadata creators. As Shirky (2008, p.47) argues Web 2.0’s social tools enable “action by loosely structured groups, operating without managerial direction and outside the profit motive”. Lagoze (2010, p. 37) advises, “the participatory nature of Web 2.0 should not be dismissed as just a popular phenomenon [or fad]”. Carletti (2016) proposes a participatory digital cultural heritage approach where Web 2.0 approaches such as crowdsourcing can be sued to enrich digital cultural objects. It is argued that “heritage crowdsourcing, community-centred projects or other forms of public participation”. On the other hand, the new collaborative approaches of Web 2.0 neither negate nor replace contemporary standards-based metadata approaches. Hence, this paper proposes a mixed metadata approach where user created metadata augments expert-created metadata and vice versa. The metadata creation process no longer remains to be the sole prerogative of the metadata expert. The Web 2.0 collaborative environment would now allow users to participate in both adding and re-using metadata. The case of expert-created (standards-based, top-down) and user-generated metadata (socially-constructed, bottom-up) approach to metadata are complementary rather than mutually-exclusive. The two approaches are often mistakenly considered as dichotomies, albeit incorrectly (Gruber, 2007; Wright, 2007) . This paper espouses the importance of enriching digital information objects with descriptions pertaining the about-ness of information objects. Such richness and diversity of description, it is argued, could chiefly be achieved by involving users in the metadata creation process. This paper presents the importance of the paradigm of metadata enriching and metadata filtering for the cultural heritage domain. Metadata enriching states that a priori metadata that is instantiated and granularly structured by metadata experts is continually enriched through socially-constructed (post-hoc) metadata, whereby users are pro-actively engaged in co-creating metadata. The principle also states that metadata that is enriched is also contextually and semantically linked and openly accessible. In addition, metadata filtering states that metadata resulting from implementing the principle of enriching should be displayed for users in line with their needs and convenience. In both enriching and filtering, users should be considered as prosumers, resulting in what is called collective metadata intelligence

CHORUS Deliverable 4.5: Report of the 3rd CHORUS Conference

The third and last CHORUS conference on Multimedia Search Engines took place from the 26th to the 27th of May 2009 in Brussels, Belgium. About 100 participants from 15 European countries, the US, Japan and Australia learned about the latest developments in the domain. An exhibition of 13 stands presented 16 research projects currently ongoing around the world

Sharing Semantic Resources

The Semantic Web is an extension of the current Web in which information, so far created for human consumption, becomes machine readable, “enabling computers and people to work in cooperation”. To turn into reality this vision several challenges are still open among which the most important is to share meaning formally represented with ontologies or more generally with semantic resources. This Semantic Web long-term goal has many convergences with the activities in the field of Human Language Technology and in particular in the development of Natural Language Processing applications where there is a great need of multilingual lexical resources. For instance, one of the most important lexical resources, WordNet, is also commonly regarded and used as an ontology. Nowadays, another important phenomenon is represented by the explosion of social collaboration, and Wikipedia, the largest encyclopedia in the world, is object of research as an up to date omni comprehensive semantic resource. The main topic of this thesis is the management and exploitation of semantic resources in a collaborative way, trying to use the already available resources as Wikipedia and Wordnet. This work presents a general environment able to turn into reality the vision of shared and distributed semantic resources and describes a distributed three-layer architecture to enable a rapid prototyping of cooperative applications for developing semantic resources