Page 191 - Sustainability Communication Interdisciplinary Perspectives and Theoritical Foundations

174 A. Möller

Fig. 15.1 Typical conversation

performance of certain kinds of acts, like making statements, asking questions,
giving orders, describing, explaining, apologizing, thanking, congratulating etc.”
(Searle et al. 1980, p. vii). These acts are called illocutionary acts.
Searle formalized different speech acts (Searle 1969) and constituted five classes
of illocutionary acts: assertives, directives (requests), commissives (promises),
declarations and expressives. From a computer science viewpoint, such a classifica-
tion is an important step, because by using these classes it is possible to formalize
conversations as a relationship between actors; conversations are processes of these
illocutionary acts. A short process is for example ‘Request (a directive of actor A) –
Commit (a commissive of actor B)’ or ‘Request (of A) – Counter-offer (a directive
of B) – Accept (a commissive of A)’. By folding conversations on the basis of
Searle’s categories (conversations are processes in time and therefore without
loops), typical patterns of conversation can be identified (Fig. 15.1). If we represent
each speech act as a symbol and a conversation as a sequence of these symbols,
diagrams like Fig. 15.1 define the grammar of a language. Winograd (1986) com-
pares a conversation with a ‘dance’ – and the term dance is used in both senses of
the word, as a ‘process’ and as a ‘system’ (like waltz or latin dances).
Computers can be used as conversation support systems. Their purpose is to
support effective conversation. Email is a very simple conversation support system.
Even if email can be treated as a task management tool supporting project manage-
ment, task delegation, information handling, scheduling, planning and social com-
munication (Dabbish et al. 2005), email systems normally do not identify patterns
of conversation but instead allow users to carry on a conversation. Users can answer
an email or they can forward it. Some email clients visualize conversations. If an
email is selected, all other emails of the respective conversation are highlighted.
However, conversation support of today’s email systems is quite poor and technical
protocols like SMTP (Simple Mail Transfer Protocol) do not support classes of
speech acts. Using subject fields and special character strings like ‘re’ or ‘fwd’ are
a less-than-ideal solution.
Instant messaging (IM) programs facilitate synchronous one-to-one communica-
tion between users in a ‘buddy list’, ‘friends list’ or in a ‘chatroom’. IM programs