A cohesive text is created in many different ways. Halliday and Has...

Text VI.

                            Critical Discourse Analysis

      We have seen that among many other resources that define the power base of a group or institution, access to or control over public discourse and communication is an important "symbolic" resource, as is the case for knowledge and information (van Dijk 1996). Most people have active control only over everyday talk with family members, friends, or colleagues, and passive control over, e.g. media usage. In many situations, ordinary people are more or less passive targets of text and talk, e.g. of their bosses or teachers, or of the authorities, such as police officers, judges, welfare bureaucrats, or tax inspectors, who may simply tell them what (not) to believe or what to do.

      On the other hand, members of more powerful social groups and institutions, and especially their leaders (the elites), have more or less exclusive access to, and control over, one or more types of public discourse. Thus, professors control scholarly discourse, teachers educational discourse, journalists media discourse, lawyers legal discourse, and politicians policy and other public political discourse. Those who have more control over more ‒ and more influential ‒  discourse (and more properties) are by that definition also more powerful.

      These notions of discourse access and control are very general, and it is one of the tasks of CDA to spell out these forms of power. Thus, if discourse is defined in terms of complex communicative events, access and control may be defined both for the context and for the structures of text and talk themselves.

(van DIJK, T. A. Critical Discourse Analysis. In: SCHIFFRIN, D.; TANNEN, D.; HAMILTON, H. (eds.).   The Handbook of Discourse Analysis, Wiley‐Blackwell, 2003. pp. 352‐371.)