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The increasing popularity of Twitter renders improved trustworthiness and relevance assessment of tweets much more important for search. However, given the limitations on the size of tweets, it is hard to extract measures for ranking from the tweet's content alone. I propose a method of ranking tweets by generating a

The increasing popularity of Twitter renders improved trustworthiness and relevance assessment of tweets much more important for search. However, given the limitations on the size of tweets, it is hard to extract measures for ranking from the tweet's content alone. I propose a method of ranking tweets by generating a reputation score for each tweet that is based not just on content, but also additional information from the Twitter ecosystem that consists of users, tweets, and the web pages that tweets link to. This information is obtained by modeling the Twitter ecosystem as a three-layer graph. The reputation score is used to power two novel methods of ranking tweets by propagating the reputation over an agreement graph based on tweets' content similarity. Additionally, I show how the agreement graph helps counter tweet spam. An evaluation of my method on 16~million tweets from the TREC 2011 Microblog Dataset shows that it doubles the precision over baseline Twitter Search and achieves higher precision than current state of the art method. I present a detailed internal empirical evaluation of RAProp in comparison to several alternative approaches proposed by me, as well as external evaluation in comparison to the current state of the art method.
ContributorsRavikumar, Srijith (Author) / Kambhampati, Subbarao (Thesis advisor) / Davulcu, Hasan (Committee member) / Liu, Huan (Committee member) / Arizona State University (Publisher)
Created2013
Description
Twitter is a micro-blogging platform where the users can be social, informational or both. In certain cases, users generate tweets that have no "hashtags" or "@mentions"; we call it an orphaned tweet. The user will be more interested to find more "context" of an orphaned tweet presumably to engage with

Twitter is a micro-blogging platform where the users can be social, informational or both. In certain cases, users generate tweets that have no "hashtags" or "@mentions"; we call it an orphaned tweet. The user will be more interested to find more "context" of an orphaned tweet presumably to engage with his/her friend on that topic. Finding context for an Orphaned tweet manually is challenging because of larger social graph of a user , the enormous volume of tweets generated per second, topic diversity, and limited information from tweet length of 140 characters. To help the user to get the context of an orphaned tweet, this thesis aims at building a hashtag recommendation system called TweetSense, to suggest hashtags as a context or metadata for the orphaned tweets. This in turn would increase user's social engagement and impact Twitter to maintain its monthly active online users in its social network. In contrast to other existing systems, this hashtag recommendation system recommends personalized hashtags by exploiting the social signals of users in Twitter. The novelty with this system is that it emphasizes on selecting the suitable candidate set of hashtags from the related tweets of user's social graph (timeline).The system then rank them based on the combination of features scores computed from their tweet and user related features. It is evaluated based on its ability to predict suitable hashtags for a random sample of tweets whose existing hashtags are deliberately removed for evaluation. I present a detailed internal empirical evaluation of TweetSense, as well as an external evaluation in comparison with current state of the art method.
ContributorsVijayakumar, Manikandan (Author) / Kambhampati, Subbarao (Thesis advisor) / Liu, Huan (Committee member) / Davulcu, Hasan (Committee member) / Arizona State University (Publisher)
Created2014
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Description
The use of blogging tools in the second language classroom has been investigated from a variety of theoretical and methodological perspectives (Alm, 2009; Armstrong & Retterer, 2008; Dippold, 2009; Ducate & Lomicka, 2008; Elola & Oskoz, 2008; Jauregi & Banados, 2008; Lee, 2009; Petersen, Divitini, & Chabert, 2008; Pinkman, 2005;

The use of blogging tools in the second language classroom has been investigated from a variety of theoretical and methodological perspectives (Alm, 2009; Armstrong & Retterer, 2008; Dippold, 2009; Ducate & Lomicka, 2008; Elola & Oskoz, 2008; Jauregi & Banados, 2008; Lee, 2009; Petersen, Divitini, & Chabert, 2008; Pinkman, 2005; Raith, 2009; Soares, 2008; Sun, 2009, 2012; Vurdien, 2011; Yang, 2009) and a growing number of studies examine the use of microblogging tools for language learning (Antenos-Conforti, 2009; Borau, Ullrich, Feng, & Shen, 2009; Lomicka & Lord, 2011; Perifanou, 2009). Grounded in Cultural Historical Activity Theory (Engestrom, 1987), the present study explores the outcomes of a semester-long project based on the Bridging Activities framework (Thorne & Reinhardt, 2008) and implemented in an intermediate hybrid Spanish-language course at a large public university in Arizona, in which students used microblogging and blogging tools to collect digital texts, analyze perspectives of the target culture, and participate as part of an online community of language learners with a broader audience of native speakers. The research questions are: (1) What technology is used by the students, with what frequency and for what purposes in both English and Spanish prior to beginning the project?, (2) What are students' values and attitudes toward using Twitter and Blogger as tools for learning Spanish and how do they change over time through their use in the project during the semester course?, and (3) What tensions emerge in the activity systems of the intermediate Spanish-language students throughout the process of using Twitter and Blogger for the project? What are the underlying reasons for the tensions? How are they resolved? The data was collected using pre-, post-, and periodic surveys, which included Likert and open-ended questions, as well as the participants' microblog and blog posts. The quantitative data was analyzed using descriptive statistics and the qualitative data was analyzed to identify emerging themes following the Constant Comparative Method (Glaser & Strauss, 1967). Finally, three participant outliers were selected as case studies for activity theoretical analysis in order to identify tensions and, through their resolution, evidence of expansive learning.
ContributorsAlvarado, Margaret (Author) / Lafford, Barbara (Thesis advisor) / González, Verónica (Committee member) / Cerron-Palomino, Alvaro (Committee member) / Arizona State University (Publisher)
Created2015
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Description
Browsing Twitter users, or browsers, often find it increasingly cumbersome to attach meaning to tweets that are displayed on their timeline as they follow more and more users or pages. The tweets being browsed are created by Twitter users called originators, and are of some significance to the browser who

Browsing Twitter users, or browsers, often find it increasingly cumbersome to attach meaning to tweets that are displayed on their timeline as they follow more and more users or pages. The tweets being browsed are created by Twitter users called originators, and are of some significance to the browser who has chosen to subscribe to the tweets from the originator by following the originator. Although, hashtags are used to tag tweets in an effort to attach context to the tweets, many tweets do not have a hashtag. Such tweets are called orphan tweets and they adversely affect the experience of a browser.

A hashtag is a type of label or meta-data tag used in social networks and micro-blogging services which makes it easier for users to find messages with a specific theme or content. The context of a tweet can be defined as a set of one or more hashtags. Users often do not use hashtags to tag their tweets. This leads to the problem of missing context for tweets. To address the problem of missing hashtags, a statistical method was proposed which predicts most likely hashtags based on the social circle of an originator.

In this thesis, we propose to improve on the existing context recovery system by selectively limiting the candidate set of hashtags to be derived from the intimate circle of the originator rather than from every user in the social network of the originator. This helps in reducing the computation, increasing speed of prediction, scaling the system to originators with large social networks while still preserving most of the accuracy of the predictions. We also propose to not only derive the candidate hashtags from the social network of the originator but also derive the candidate hashtags based on the content of the tweet. We further propose to learn personalized statistical models according to the adoption patterns of different originators. This helps in not only identifying the personalized candidate set of hashtags based on the social circle and content of the tweets but also in customizing the hashtag adoption pattern to the originator of the tweet.
ContributorsMallapura Umamaheshwar, Tejas (Author) / Kambhampati, Subbarao (Thesis advisor) / Liu, Huan (Committee member) / Davulcu, Hasan (Committee member) / Arizona State University (Publisher)
Created2015