Results 1 - 10
of
19
Folks in Folksonomies: Social Link Prediction from Shared Metadata
"... Web 2.0 applications have attracted a considerable amount of attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and semantic components of social media has been only partially explored. ..."
Abstract
-
Cited by 52 (5 self)
- Add to MetaCart
(Show Context)
Web 2.0 applications have attracted a considerable amount of attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and semantic components of social media has been only partially explored. Here we focus on Flickr and Last.fm, two social media systems in which we can relate the tagging activity of the users with an explicit representation of their social network. We show that a substantial level of local lexical and topical alignment is observable among users who lie close to each other in the social network. We introduce a null model that preserves user activity while removing local correlations, allowing us to disentangle the actual local alignment between users from statistical effects due to the assortative mixing of user activity and centrality in the social network. This analysis suggests that users with
Analysis of participation in an online photo-sharing community: A multidimensional perspective
- Journal of the American Society for Information Sciences and Technology
"... In recent years we have witnessed a significant growth of social-computing communities—online services in which users share information in various forms. As content contributions from participants are critical to the viability of these communities, it is important to understand what drives users to ..."
Abstract
-
Cited by 19 (2 self)
- Add to MetaCart
In recent years we have witnessed a significant growth of social-computing communities—online services in which users share information in various forms. As content contributions from participants are critical to the viability of these communities, it is important to understand what drives users to participate and share information with others in such settings. We extend previous literature on user contribution by studying the factors that are associated with various forms of participation in a large online photo-sharing community. Using survey and system data, we examine four different forms of participation and consider the differences between these forms. We build on theories of motivation to examine the relationship between users ’ participation and their motivations with respect to their tenure in the community. Amongst our findings, we identify individual motivations (both extrinsic and intrinsic) that underpin user participation, and their effects on different forms of information sharing; we show that tenure in the community does affect participation, but that this effect depends on the type of participation activity. Finally, we demonstrate that tenure in the community has a weak moderating effect on a number of motivations with regard to their effect on participation. Directions for future research, as well as implications for theory and practice, are discussed.
Friendship prediction and homophily in social media
- ACM Transactions on the Web
"... Web 2.0 applications have attracted considerable attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and topical components of social media has been only partially explored. Here we stud ..."
Abstract
-
Cited by 16 (4 self)
- Add to MetaCart
Web 2.0 applications have attracted considerable attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and topical components of social media has been only partially explored. Here we study the presence of homophily in three systems that combine tagging of social media with online social networks. We find a substantial level of topical similarity among users who lie close to each other in the social network. We introduce a null model that preserves user activity while removing local correlations, allowing us to disentangle the actual local similarity between users from statistical effects due to the assortative mixing of user activity and centrality in the social network. This analysis suggests that users with similar interests are more likely to be friends, and therefore topical similarity measures among users based solely on their annotation metadata should be predictive of social links. We test this hypothesis on several datasets, confirming that social networks constructed from topical similarity capture actual friendship accurately.
Collective Indexing of Emotions in Images. A Study in Emotional Information Retrieval
"... Some documents provoke emotions in people viewing them. Will it be possible to describe emotions consistently and use this information in retrieval systems? We tested collective (statistically aggregated) emotion indexing using images as examples. Considering psychological results, basic emotions ar ..."
Abstract
-
Cited by 12 (1 self)
- Add to MetaCart
Some documents provoke emotions in people viewing them. Will it be possible to describe emotions consistently and use this information in retrieval systems? We tested collective (statistically aggregated) emotion indexing using images as examples. Considering psychological results, basic emotions are anger, disgust, fear, happiness, and sadness. This study follows an approach developed by Lee and Neal (2007) for music emotion retrieval and applies scroll bars for tagging basic emotions and their intensities. A sample comprising 763 persons tagged emotions caused by images (retrieved from www.Flickr.com) applying scroll bars and (linguistic) tags. Using SPSS, we performed descriptive statistics and correlation analysis. For more than half of the images, the test persons have clear emotion favorites. There are prototypical images for given emotions. The document-specific consistency of tagging using a scroll bar is, for some images, very high. Most of the (most commonly used) linguistic tags are on the basic level (in the sense of Rosch’s basic level theory). The distributions of the linguistic tags in our examples follow an inverse power-law. Hence, it seems possible to apply collective image emotion tagging to image information systems and to present a new search option for basic emotions. This article is one of the first steps in the research area of emotional information retrieval (EmIR).
F.: Caching content-based queries for robust and efficient image retrieval
- In: EDBT 2009: Proceedings of the 12th International Conference on Extending Database Technology
, 2009
"... In order to become an effective complement to traditional Web-scale text-based image retrieval solutions, content-based image retrieval must address scalability and efficiency issues. In this paper we investigate the possibility of caching the answers to content-based image retrieval queries in metr ..."
Abstract
-
Cited by 7 (2 self)
- Add to MetaCart
(Show Context)
In order to become an effective complement to traditional Web-scale text-based image retrieval solutions, content-based image retrieval must address scalability and efficiency issues. In this paper we investigate the possibility of caching the answers to content-based image retrieval queries in metric space, with the aim of reducing the average cost of query processing, and boosting the overall system throughput. Our proposal exploits the similarity between the query object and the cache content, and allows the cache to return approximate answers with acceptable quality guarantee even if the query processed has never been encountered in the past. Moreover, since popular images that are likely to be used as query have several near-duplicate versions, we show that our caching algorithm is robust, and does not suffer of cache pollution problems due to near-duplicate query objects. We report on very promising results obtained with a collection of one million high-quality digital photos. We show that it is worth pursuing caching strategies also in similarity search systems, since the proposed caching techniques can have a significant impact on performance, like caching on text queries has been proven effective for traditional Web search engines.
Article Automatically Augmenting Lifelog Events using Pervasively Generated Content from Millions of People
, 2010
"... sensors ..."
(Show Context)
Building Confederated Web-based Services with Priv.io
"... With the increasing popularity of Web-based services, users today have access to a broad range of free sites, including social networking, microblogging, and content sharing sites. In order to offer a service for free, service providers typically monetize user content, selling results to third parti ..."
Abstract
-
Cited by 3 (0 self)
- Add to MetaCart
(Show Context)
With the increasing popularity of Web-based services, users today have access to a broad range of free sites, including social networking, microblogging, and content sharing sites. In order to offer a service for free, service providers typically monetize user content, selling results to third parties such as advertisers. As a result, users have little control over their data or privacy. A numberof alternative approaches to architectingtoday’s Web-basedservices havebeenproposed, but they suffer from limitations such as relying the creation and installation of additional client-side software, providing insufficient reliability, or imposing an excessive monetary cost on users. In this paper, we present Priv.io, a new approach to building Web-based services that offers users greater control and privacy over their data. We leverage the fact that today, users can purchase storage, bandwidth, and messaging from cloud providers at fine granularity: In Priv.io, each user provides the resources necessary to support their use of the service using cloud providers such as Amazon Web Services. Users still access theservice usingaWebbrowser, all computation is done within users ’ browsers, and Priv.io provides rich and secure support for third-party applications. An implementation demonstrates that Priv.io works today with unmodified versions of common Web browsers on both desktop and mobile devices, is both practical and feasible, and is cheap enough for the vast majority users.
Friendship, collaboration and semantics in Flickr: from social interaction to semantic similarity
"... We study the semantic assortativity in the social networks hosted by the Flickr folksonomy, based both on the contact data and on the group membership data provided by the users. The social network built this way are complex one. Besides, one observes a clear assortativity pattern, stronger than in ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
(Show Context)
We study the semantic assortativity in the social networks hosted by the Flickr folksonomy, based both on the contact data and on the group membership data provided by the users. The social network built this way are complex one. Besides, one observes a clear assortativity pattern, stronger than in a suitable null model adopted for a comparison. Nevertheless, such semantical similarity does not appear to develop during the community evolution, but is rather the result of a pre-existing shared background between users.
(Query) History Teaches Everything, Including the Future (Invited Paper)
"... “History Teaches Everything, Including the Future”, wrote Alphonse de Lamartine in the nineteen century. Even if history cannot be really considered a predic-tive science, historical information can successfully be used in many fields. This paper deals with Web Search Engines and their Query logs, w ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
(Show Context)
“History Teaches Everything, Including the Future”, wrote Alphonse de Lamartine in the nineteen century. Even if history cannot be really considered a predic-tive science, historical information can successfully be used in many fields. This paper deals with Web Search Engines and their Query logs, which contain historical information about past usage of such systems. We will present some of the most interesting results obtained in this field by the High Performance Computing Lab in Pisa in collaboration with Research Labs worldwide. The techniques reviewed are mainly focused on enhanc-ing the efficiency of large–scale distributed search sys-tems. 1
A picture of Instagram is worth more than a thousand words: Workload characterization and application
"... Abstract—Participatory sensing systems (PSSs) have the po-tential to become fundamental tools to support the study, in large scale, of urban social behavior and city dynamics. To that end, this work characterizes the photo sharing system Instagram, considered one of the currently most popular PSS on ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—Participatory sensing systems (PSSs) have the po-tential to become fundamental tools to support the study, in large scale, of urban social behavior and city dynamics. To that end, this work characterizes the photo sharing system Instagram, considered one of the currently most popular PSS on the Internet. Based on a dataset of approximately 2.3 million shared photos, we characterize user’s behavior in the system showing that there are several advantages and opportunities for large scale sensing, such as a global coverage at low cost, but also challenges, such as a very unequal photo sharing frequency, both spatially and temporally. We also observe that the temporal photo sharing pattern is a good indicator about cultural behaviors, and also says a lot about certain classes of places. Moreover, we present an application to identify regions of interest in a city based on data obtained from Instagram, which illustrates the promising potential of PSSs for the study of city dynamics. I.
