Topic modeling with tweets is difficult due to the short and informal nature of the texts. Tweet-pooling (aggregation of tweets into longer documents prior to training) has been shown to improve model outputs, but performance varies depending on the pooling scheme and data set used. Here we investigate a new tweet-pooling method based on network structures associated with Twitter content. Using a standard formulation of the well-known Latent Dirichlet Allocation (LDA) topic model, we trained various models using different tweet-pooling schemes on three diverse Twitter datasets. Tweet-pooling schemes were created based on mention/reply relationships between tweets and Twitter users, with several (non-networked) established methods also tested as a comparison. Results show that pooling tweets using network information gives better topic coherence and clustering performance than other pooling schemes, on the majority of datasets tested. Our findings contribute to an improved methodology for topic modeling with Twitter content.

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Citation analysis is considered as major and one of the most popular branches of bibliometrics. Citation analysis is based on the assumption that all citations have similar values and weights each equally. Specic research elds like content-based citation analysis (CCA) seeks to explain the "how" and "why" of citation behavior. In this paper we tackle to explain the "how" from a centrality indicator based on factors which are built automatically according to the authors' citation behavior. This indicator allows to evaluate bibliographical references' importance for reading the paper with which user interacts. From objective quantitative measurements, factors are computed in order to characterize the level of granularity where citations are used. By the setting of the centrality indicator's factors we can highlight citations which tend towards a partial or a global construction of the authors' discourse. We carry out a pilot study in which we test our approach on some papers and discuss the challenges in carrying out the citation analysis in this context. Our results show interesting and consistent correlations between the level of granularity and the signicance of citation inuences.

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