Marcelo Mendoza

Dr. Marcelo Mendoza

Department of Computer Science, Pontificia Universidad Católica de Chile, Santiago, P.O. 8320000, Chile

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 March 2011
Verified
Conference Paper
Open access
PDF file
CCCarlos Castillo
Carlos Castillo
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza
BPBarbara Poblete
Barbara Poblete
We analyze the information credibility of news propagated through Twitter, a popular microblogging service. Previous research has shown that most of the messages posted on Twitter are truthful, but the service is also used to spread misinformation and false rumors, often unintentionally. On this paper we focus on automatic methods for assessing the credibility of a given set of tweets. Specifically, we analyze microblog postings related to "trending" topics, and classify them as credible or not credible, based on features extracted from them. We use features from users' posting and re-posting ("re-tweeting") behavior, from the text of the posts, and from citations to external sources. We evaluate our methods using a significant number of human assessments about the credibility of items on a recent sample of Twitter postings. Our results shows that there are measurable differences in the way messages propagate, that can be used to classify them automatically as credible or not credible, with precision and recall in the range of 70% to 80%.

25 July 2010
Verified
Conference Paper
Open access
PDF file
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza
BPBarbara Poblete
Barbara Poblete
CCCarlos Castillo
Carlos Castillo
In this article we explore the behavior of Twitter users under an emergency situation. In particular, we analyze the activity related to the 2010 earthquake in Chile and characterize Twitter in the hours and days following this disaster. Furthermore, we perform a preliminary study of certain social phenomenons, such as the dissemination of false rumors and confirmed news. We analyze how this information propagated through the Twitter network, with the purpose of assessing the reliability of Twitter as an information source under extreme circumstances. Our analysis shows that the propagation of tweets that correspond to rumors differs from tweets that spread news because rumors tend to be questioned more than news by the Twitter community. This result shows that it is posible to detect rumors by using aggregate analysis on tweets.

14 October 2013 in Internet Research
Verified
Journal Article
Closed access
CCCarlos Castillo
Carlos Castillo
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza
BPBarbara Poblete
Barbara Poblete
Artículo de publicación ISIPurpose – Twitter is a popular microblogging service which has proven, in recent years, its potential for propagating news and information about developing events. The purpose of this paper is to focus on the analysis of information credibility on Twitter. The purpose of our research is to establish if an automatic discovery process of relevant and credible news events can be achieved. Design/methodology/approach – The paper follows a supervised learning approach for the task of automatic classification of credible news events. A first classifier decides if an information cascade corresponds to a newsworthy event. Then a second classifier decides if this cascade can be considered credible or not. The paper undertakes this effort training over a significant amount of labeled data, obtained using crowdsourcing tools. The paper validates these classifiers under two settings: the first, a sample of automatically detected Twitter “trends” in English, and second, the paper tests how well this model transfers to Twitter topics in Spanish, automatically detected during a natural disaster. Findings – There are measurable differences in the way microblog messages propagate. The paper shows that these differences are related to the newsworthiness and credibility of the information conveyed, and describes features that are effective for classifying information automatically as credible or not credible. Originality/value – The paper first tests the approach under normal conditions, and then the paper extends the findings to a disaster management situation, where many news and rumors arise. Additionally, by analyzing the transfer of our classifiers across languages, the paper is able to look more deeply into which topic-features are more relevant for credibility assessment. To the best of our knowledge, this is the first paper that studies the power of prediction of social media for information credibility, considering model transfer into time-sensitive and language-sensitive contexts

1 January 2004
Verified
Book Chapter
Closed access
PDF file
RBRicardo Baeza-Yates
Ricardo Baeza-Yates
CHCarlos Hurtado
Carlos Hurtado
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza

1 October 2014 in Knowledge-Based Systems
Verified
Journal Article
Closed access
FBFelipe Bravo-Marquez
Felipe Bravo-Marquez
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza
BPBarbara Poblete
Barbara Poblete

17 September 2016 in Scientometrics
Verified
Journal Article
Open access
PDF file
MGMiguel Guevara
Miguel Guevara
DHDominik Hartmann
Dominik Hartmann
MAManuel Aristarán
Manuel Aristarán
Marcelo MendozaMarcelo Mendoza
Marcelo Mendoza
CHCésar A. Hidalgo
César A. Hidalgo
In recent years scholars have built maps of science by connecting the academic fields that cite each other, are cited together, or that cite a similar literature. But since scholars cannot always publish in the fields they cite, or that cite them, these science maps are only rough proxies for the potential of a scholar, organization, or country, to enter a new academic field. Here we use a large dataset of scholarly publications disambiguated at the individual level to create a map of science—or research space—where links connect pairs of fields based on the probability that an individual has published in both of them. We find that the research space is a significantly more accurate predictor of the fields that individuals and organizations will enter in the future than citation based science maps. At the country level, however, the research space and citations based science maps are equally accurate. These findings show that data on career trajectories—the set of fields that individuals have previously published in—provide more accurate predictors of future research output for more focalized units—such as individuals or organizations—than citation based science maps.