Type A: bi-directional exchange, face to face, with free turn-taking:
- conversations at home;
- conversations at work;
- conversations at school or at the university;
- conversations during recreation or on means of transport.
Type B: bi-directional exchange, not face to face, with free turn-taking:
- normal telephone conversations;
- telephone conversations broadcasted on radio;
- messages recorded by telephone answering machines.
Type C: bi-directional exchange, face to face, with regulated turn-taking:
- legislative assemblies;
- cultural discussions;
- assemblies at school;
- labor union assemblies;
- meetings of workers;
- oral exams in the elementary school;
- oral exams in the secondary school;
- oral exams at the university;
- interrogations in the courtroom;
- interviews on radio or television.
Type D: unidirectional exchange, with the addressee being present:
- lessons in the elementary school;
- lessons in the secondary school;
- university lectures;
- speeches held during party conventions or labor union meetings;
- presentations at scientific meetings;
- speeches held during electoral campaigns;
- presentations at non-specialist meetings;
- court pleadings.
Type E: distanced unidirectional exchange:
- television programs;
- radio programs.
Source: De Mauro, Mancini, Vedovelli, Voghera 1993: 35ff.