1438 Copyright © 2016, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 65 DOI: 10.4018/978-1-4666-8619-9.ch065 A Linguistic Approach to Identify the Affective Dimension Expressed in Textual Messages ABSTRACT The digital mediation resources used in Distance Education can hinder the teacher’s perception about the student’s state of mind. However, the textual expression in natural language is widely encouraged in most Distance Education courses, through the use of Virtual Learning Environments and other digital tools. This fact has motivated research eforts in order to identify feelings expressed by students in textual messages. A signifcant part of the known approaches in this area apply textual analysis without a deep linguistic representation, which can lead to some weakness in the results obtained. This paper reports an approach using theories of Computational Lexical Semantics for the representation of the lexicon of emotion. The methodology was developed through studies regarding corpus analysis, lexical unit descrip- tion, and the implementation of a computational system to identify the feelings expressed in the textual messages in natural language, using the lexicon of emotion. This system was used in evaluation experi- ments that indicate improvements when comparing the adopted approach with other similar approaches. INTRODUCTION The dynamics of digital mediation used in Dis- tance Education (DE) generates contexts that can drive to student isolation or little integration with colleagues. However, the use of subsidies gener- ated in this digital mediation interaction process in Virtual Learning Environments (VLE) allows the creation of resources that can promote closer student-teacher relations. Some examples of these situations are the use of the students’ textual production and their interaction data in order to Sandro José Rigo University of Vale do Rio dos Sinos (UNISINOS), Brazil Isa Mara da Rosa Alves University of Vale do Rio dos Sinos (UNISINOS), Brazil Jorge Luis Victória Barbosa University of Vale do Rio dos Sinos (UNISINOS), Brazil