2.1. Models of turn-taking in conversation
Over the last 25 years this topic has attracted much interest. It has been investigated in two ways: first, by analyzing transcriptions of naturally occurring conversations; and second, by analyzing video-recordings, with an emphasis on the role played by nonverbal signals.⁶

The first of these methods, labelled ´conversational analysis´ was pioneered by SACKS / SCHEGLOFF / JEFFERSON. In 1974 they conducted a seminal investigation of the ubiquitous phenomenon of turn-taking in conversations. They described how participants, through their conversation, adapt the turn-taking system and create for themselves the social occasion they intend.⁷ They began with the gross empirical observation that in odinary conversa- tions (1) although who is speaking changes, members speak one at a time, usually for varying lengths of time; (2) the transitions between speakers are "finely coordinated"; (3) general methods exist for allocating who speaks next; and (4) specific methods exist for constructing utterances so that the utterance displays ist status both as a following turn and as an utterance that allocates a next turn.⁸ The rules defined here function as an unnoticed resource that participants use for carrying on a conversation.

On the other hand DUNCAN (1972), DUNCAN / FISKE (1977), or WIEMANN / KNAPP (1975) have carried out observational studies of conversational interaction which have suggested that gestural behaviour, in addition to speaker gaze, are of considerable importance in regulating the flow of social encounters.

Today there is a large, valuable, and robust body of knowledge generated by many studies, which used a variety of analytical methods.⁹

The actual research often is concerned with the problems of turn-taking in discourse, especially as applied to intelligent interfaces, such as advice-giving systems or software help systems. A limitation of many discourse systems is their need for explicit turn-ending signals (e.g. pressing a return key).¹⁰

2.2. Development of turn-taking skills
Turn-taking skills develop early. It has been found that the child begins to acquire knowledge about this organization of togetherness¹¹ and its characteristic patterning which exists in and builds up the dialogue. It has been observed that communicative interaction, manifested in eye glances and taking place from the first week, gradually develops into an interaction with sounds where the adult talks and the child is cooing. So, at the early age of three or four months, the child has learnt the role play of conversation. As the child develops, his basic conversational skills develop with him. It may be suggested that nursery school children have already acquired certain aspects of those skills, including the gestural behaviour.