Dialogue is about the organization of communication as a series of turns between communication partners. The core elements of dialogue are communication turns, the communication context, and turn interpretation. Dialogue interaction includes speech-based and graphical interactions. Dialogue can be understood as computation, goal-directed action, communication, or embodied action.

Kirsh argued that we are not just passively reacting to computer-generated options. If we look at interaction at a higher level, beyond a single action, we see that users are also actively influencing their environments. Users are 'architects' of their environments, as Kirsh put it.

Kirsh points out that Norman's model makes an unrealistic assumption: The user is assumed to know the environment and its options and is merely picking an option. In practice, we do not always know what the options mean or even what options are available. Kirsh argued that users need to actively explore interfaces to become aware of the available functions and how they work.

Mixed-initiative interaction is the idea of organizing interaction in dialogue where both the computer and the human can take initiative. Unlike in the case of an FSM, the computing system can take action without a command from the user; the initiative is mixed.

Code-switching refers to a switch in language to match the capabilities of the communication partner.

Communication repair refers to the 'work of restoring shared understanding' when conversational partners misunderstand each other.

Robustness refers to the communication partners' ability to achieve shared understanding even in light of misunderstandings and other unanticipated troubles.

Human–machine interaction, according to Suchman, is similar to but different from human–human dialogue. It is similar in the sense that people pursue a shared understanding: They actively work to make themselves understood. It is different in the sense that the communication abilities of computers are limited, which requires humans to adapt.

FSMs are an effective way to describe how dialogue is structured; however, they are limited to memory-free dialogue.

An FSM is a model of discrete computation applicable to dialogues.

A mode refers to the variation in the interpretation of a user's input according to an internal state. In a modeless dialogue, all inputs are possible in all states and their interpretation is always the same.

Dialogue can be described using models of computation from computer science. Such models include finite state machines (FSMs), pushdown automata, and Petri nets.

Affordance, which we discussed in Chapter 3, refers to how well users can interpret what actions are possible with a widget. Visibility is a handy related concept in design that underlies direct manipulation interfaces.

Mapping and feedback are crucial concepts for understanding a computer's turn.

Gulf of evaluation: This gulf refers to knowing how a perceived change in the computer has moved it closer to the intended goal state.

Gulf of execution: This gulf is about knowing what to do to bring about a desired state change in the computer.

Norman offered two central concepts to help us understand these cognitive efforts: the gulf of execution and the gulf of evaluation. These two concepts describe inferential breakpoints for users seeking to express their intentions and interpret feedback from the system, respectively.

A significant early theory of dialogue interaction is the seven-stage model of Norman [600]. It considers interaction as goal-directed, turn-based dialogue.

both the computer and the user may have initiative. For example, a pop-up window can be presented to confirm a risky selection. When there is a misunderstanding about the context of the dialogue, errors may happen, and the partners must recover from them.

both the computer and the human participate in establishing a shared context. The computer does not simply receive a message; it also communicates the effects of that message. Therefore, the design of feedback, affordances, and cues is central to dialogue-based interaction.

in dialogue, acts of communication are conditional: The meaning of a turn depends on the communication context.

the concepts of dialogue are applicable across modalities.

The key idea in the dialogue view of interaction is the organization of communication as a series of turns. Dialogue evolves through communication turns between two or more partners. In one turn, an appropriate communication act is made by one partner based on the communication context.