Twitter is a worldwide social media platform where millions of people frequently express ideas and opinions
about any topic. This widespread success makes the analysis of tweets an interesting and possibly
lucrative task, being those tweets rarely objective and becoming the targeting for large-scale analysis. In
this paper, we explore the idea of integrating two fundamental aspects of a tweet, the proper textual
content and its underlying structural information, when addressing the tweet categorization task. Thus,
not only we analyze textual content of tweets but also analyze the structural information provided by the
relationship between tweets and users, and we propose different methods for effectively combining both
kinds of feature models extracted from the different knowledge sources. In order to test our approach, we
address the specific task of determining the political opinion of Twitter users within their political context,
observing that our most refined knowledge integration approach performs remarkably better (about
5 points above) than the textual-based classic modelMinisterio de Economía y Competitividad TIN2012-38536-C03-02Junta de Andalucía P11-TIC-7684 M
