1. MTCMTC Control Systems Group, Crieff Hills, 2005 The Layered Protocol Theory of Dialogue M. M. Taylor Martin Taylor Consulting mmt@mmtaylor.net

2. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the originators view A dialogue involves two people: an originator we call Oliver and a recipient we call Rachel Oliver initiates the dialogue because he has a reference for his perception of Rachel. This reference is for Rachel to understand something or to perform some action. From Olivers point of view, the dialogue is successful when Oliver perceives Rachel to understand or to act according to his reference value for his perception of her. Olivers reference state for his perception of Rachel is called the Primal Message Primal Message Virtual Message Feedback Oliver Rachel Olivers view of the dialogue

3. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the recipients view The recipients view of the dialogue is more complex. Rachel perceives that Oliver wants to convey a message (i.e. to have her understand something or to act in some way). This perception may be tantamount to a disturbance of one or more controlled perceptions, such as to perceive Oliver to be satisfied with her understanding or her actions. If Olivers attempt to initiate a dialogue does not disturb any of Rachels controlled perceptions, she will not act, and Olivers Virtual Message will not influence his perception of her state (at least not in respect of that Primal Message). Perceive Oliver to be satisfied Oliver Rachel Rachels view of the dialogue Virtual Message A disturbance Acknowledgment

4. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: both views Rachels perception Olivers satisfaction has been disturbed, and since she is controlling that perception, she will act in a way that Oliver can perceive. She will acknowledge Olivers initiation. Oliver sees this as feedback. Primal Message Virtual Message Feedback Oliver Rachel Olivers view of the dialogue Perceive Oliver to be satisfied Oliver Rachel Rachels view of the dialogue A disturbance Acknowledgment

5. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view The external analyst cannot see the reference perceptions of either party. Nor, really, can the analyst see either the intended or the received meanings of the Virtual Message or the Acknowledgment. In most cases, the Analyst can observe the physical manifestations of the Virtual Message and the Acknowledgment in the communication medium (e.g. the sounds of the voices, the gestural movements of hands and face, etc.), but not the perceptual effects of those physical manifestations on the dialogue partners. Virtual Message Oliver Rachel Acknowledgment

6. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view of Layers and Protocols. Oliver, Rachel, and the Analyst are in the same boat. They can only see or hear the actions of the dialogue partner, and must infer their intent. But Oliver and Rachel can apply The Test, whereas the Analyst can only observe. Virtual Message OliverRachel Acknowledgment Physical media Translations

7. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view of Layers and Protocols. What does Rachels acknowledgment do? There are several possibilities. 1.It brings Olivers perception to its reference value (the Primal Message has been passed). In other words, Oliver perceives that Rachel has understood or acted as he wished. 2.It allows Oliver to perceive that Rachel has not understood, but also that Rachel is prepared to receive the Primal Message. Or not, as the case may be. Virtual Message OliverRachel Acknowledgment Physical media Translations

8. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view of Layers and Protocols. What does Rachels acknowledgment do? More possibilities. 3.It brings Rachels perception to its reference value (Oliver is satisfied). In other words, Rachel perceives that its effect on Oliver allows her to perceive that the Primal Message has been passed. 4.It serves as a Primal Message of another kind, from Rachel to Oliver, with the intent of allowing Oliver to perceive in what way Rachel has not completely received the Primal Message. Virtual Message OliverRachel Acknowledgment Physical media Translations

9. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view of Layers and Protocols. Note possibility 4: Rachels acknowledgment serves as a Primal Message of another kind, from Rachel to Oliver, with the intent of allowing Oliver to perceive in what way Rachel has not completely received the Primal Message. At this point, the analyst should see two simultaneous Primal Messages being passed, one from Oliver to Rachel, about what he wants her to understand or do, and one from Rachel to Oliver, about the current state of her understanding of his initial Primal Message. Rachels message is a Protocol Message, which Oliver can acknowledge. Protocol messages support the transmission of the content of Olivers Primal Message, by letting Oliver know what Rachel believes about her understanding. Protocol messages from Oliver to Rachel help Rachel to perceive what Oliver believes about the current state of the transmission of the Primal Message. Other virtual messages, which may be embodied in the same physical manifestation as are the Protocol messages, allow Oliver to reduce the error in his perception of Rachel, for which the reference value is the initial Primal Message.

10. MTCMTC Control Systems Group, Crieff Hills, 2005 The structure of a dialogue: the external Analysts view of the General Protocol Grammar (GPG) Our early work on Layered Protocol Theory (before, say, 1990) was designed not to explain human communication, but to ease Human-Computer Interaction. We developed a General Protocol Grammar, which was intended to be applicable at any level in the translation hierarchy between the top-level Virtual Message and its Acknowledgment and their bottom-level physical manifestations. We found, however, that essentially the same GPG described real human dialogue. Heres a small, but important, part of it, drawn in the intelligible, but misleading form of a flow chart. It is misleading because it carries the implication that the dialogue is in some one state and changes state as a consequence of actions by one party after the other in alternation. A real dialogue isnt like that. Start Primary Normal Ack Problem Resolution Edit Problem Accept Change End

11. MTCMTC Control Systems Group, Crieff Hills, 2005 Virtual Message OliverRachel Acknowledgment Physical media Translations Virtual Message Acknowledgment Layers

12. MTCMTC Control Systems Group, Crieff Hills, 2005 Start Primary Normal Ack Problem Resolution Edit Problem Accept Change End One Virtual Message Start Primary Normal Ack Problem Resolution Edit Problem Accept Change End A supporting (lower-level) Virtual Message Layers and Protocols

13. MTCMTC Control Systems Group, Crieff Hills, 2005 Layers and Protocols To pass a complex message (e.g. the General Theory of relativity) may take years and thousands of supporting messages that involve words and pictures. To pass a simple message (e.g. Im skeptical) may take no more than a slight lift of an eyebrow, with no words being involved at all. In fact, some messages can be conveyed by a failure to act at all. Start End Start End Start End Start End Start End Concepts Supporting concepts Words and Gestures Start End Sound and Sight

14. MTCMTC Control Systems Group, Crieff Hills, 2005 Layers and Protocols The instantiations of the various elements of the GPG are likely to be different from level to level. Repeated use of the Edit loop is probable if the Primal Message is a complex concept. Almost all the arcs will be unused or have null instantiations if the Primal message is a word spoken clearly in a mutually understood language. Start End Start End Start End Start End Start End Concepts Supporting concepts Words and Gestures Start End Sound and Sight

15. MTCMTC Control Systems Group, Crieff Hills, 2005 The Layered Protocol Theory of Dialogue M. M. Taylor Martin Taylor Consulting mmt@mmtaylor.net