R. A. Baeza-yates and B. Ribeiro-neto, Modern Information Retrieval, 1999.

D. M. Blei, A. Y. Ng, and M. I. Jordan, Latent dirichlet allocation, Journal of Machine Learning Research, vol.3, pp.993-1022, 2003.

J. Cohen, Weighted kappa: Nominal scale agreement provision for scaled disagreement or partial credit., Psychological Bulletin, vol.70, issue.4, pp.213-220, 1968.
DOI : 10.1037/h0026256

R. Effing, J. Van-hillegersberg, and T. Huibers, Social Media and Political Participation: Are Facebook, Twitter and YouTube Democratizing Our Political Systems?, Electronic Participation, pp.25-35, 2011.
DOI : 10.1007/978-3-642-23333-3_3

URL : http://doc.utwente.nl/84267/1/Huibers_Social_Media_and_Political_Participation_2011.pdf

A. Esuli and F. Sebastiani, Determining term subjectivity and term orientation for opinion mining, Proceedings of the Conference of the European Chapter of the Association for Computational Linguistics (EACL), 2006.

N. S. Glance, M. Hurst, and T. Tomokiyo, Blogpulse: Automated trend discovery for weblogs, WWW 2004 Workshop on the webblogging ecosystem: Aggregation, Analysis, and Dynamics, 2004.

M. Hu and B. Liu, Mining and summarizing customer reviews, Proceedings of the 2004 ACM SIGKDD international conference on Knowledge discovery and data mining , KDD '04, 2004.
DOI : 10.1145/1014052.1014073

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=

S. M. Kim and E. Hovy, Determining the sentiment of opinions, Proceedings of the 20th international conference on Computational Linguistics , COLING '04, 2004.
DOI : 10.3115/1220355.1220555

D. Mackay, Information Theory, Inference and Learning Algorithms, chap. 20: An Example Inference Task: Clustering, pp.284-292, 2003.

M. Maragoudakis, E. Loukis, and Y. Charalabidis, A Review of Opinion Mining Methods for Analyzing Citizens? Contributions in Public Policy Debate, Electronic Participation, pp.298-313, 2011.
DOI : 10.1007/978-3-642-23333-3_26

A. Mccallum, Information extraction, Queue, vol.3, issue.9, pp.48-57, 2005.
DOI : 10.1145/1105664.1105679

A. K. Mccallum, MALLET: A Machine Learning for Language Toolkit, 2002.

Q. Mei, C. Liu, H. Su, and C. Zhai, A probabilistic approach to spatiotemporal theme pattern mining on weblogs, Proceedings of the 15th international conference on World Wide Web , WWW '06, pp.533-542, 2006.
DOI : 10.1145/1135777.1135857

T. Nanno, T. Fujiki, Y. Suzuki, and M. Okumura, Automatically collecting, monitoring, and mining japanese weblogs, Proceedings of the 13th international World Wide Web conference on Alternate track papers & posters , WWW Alt. '04, pp.320-321, 2004.
DOI : 10.1145/1013367.1013455

B. Pang and L. Lee, Opinion Mining and Sentiment Analysis, Foundations and Trends? in Information Retrieval, vol.2, issue.1?2, pp.1-135, 2008.
DOI : 10.1561/1500000011

S. Somasundaran and J. Wiebe, Recognizing stances in ideological on-line debates, Proceedings of the NAACL HLT 2010 Workshop on Computational Approaches to Analysis and Generation of Emotion in Text, 2010.
DOI : 10.3115/1687878.1687912

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=

M. Steyvers and T. Griffiths, Latent Semantic Analysis: A Road to Meaning, chap. Probabilistic topic models. Laurence Erlbaum (2007) 18. sync3: Eu project sync3, 2011.

O. Saebø, Understanding TwitterTM Use among Parliament Representatives: A Genre Analysis, Electronic Participation, pp.1-12, 2011.
DOI : 10.1007/978-3-642-23333-3_1

P. Teufl, U. Payer, and P. Parycek, Automated Analysis of e-Participation Data by Utilizing Associative Networks, Spreading Activation and Unsupervised Learning, Lecture Notes in Computer Science, vol.17, issue.8-9, pp.139-150, 2009.
DOI : 10.3115/980432.980692

K. Tserpes, M. Jacovi, M. Gardner, A. Triantafillou, and B. Cohen, +Spaces: Intelligent Virtual Spaces for eGovernment, 2010 Sixth International Conference on Intelligent Environments, 2010.
DOI : 10.1109/IE.2010.65

URL : http://repository.essex.ac.uk/3853/1/IE10%2520paper_final_noauth.pdf