The Cooperative Principle
Watch this video for a crash course on how to write dialog that’s comfortable, frictionless, and user-centric by applying the Cooperative Principle.
James Giangola, on applications of the Cooperative Principle to Voice User Interfaces, at Google I/O 2017
According to the Cooperative Principle, efficient communication relies on the assumption that there’s an undercurrent of cooperation between conversational participants.
The Cooperative Principle can be understood in terms of four rules, called Grice’s Maxims.
We instinctively cooperate in terms of...
Maxim (or rule)
...the truth of what we say
Maxim of Quality
...the quantity of information that we provide
Maxim of Quantity
...the relevance of what we contribute
Maxim of Relevance
...the way we strive to communicate clearly, without obscurity or ambiguity
Maxim of Manner
Research has shown that people respond to technology as they would to another human. This means users rely on their existing model of human-to-human conversation and follow the Cooperative Principle even when interacting with the persona of a conversational user interface, and they expect your persona to follow it, too.
Expect users to be informative.
Because users are cooperative, they often offer more information than is literally required of them.
Get the dialog back on track.
Your persona won’t always be able to handle cooperative responses. In these cases, rely on lightweight and conversational error handling to get the dialog back on track in a way that doesn’t draw attention to the error.
Move the conversation forward.
Like your users, your persona should also be cooperative and informative, offering as much information as is necessary to advance the conversation.
Optimize for relevance.
In conversation, saying too much is as uncooperative as saying too little. Facilitate comprehension by keeping turns brief and optimally relevant from the user’s point of view.
Listen between the lines.
Knowing what someone said is not the same as knowing what they meant. People often suggest things rather than state them explicitly. Our ability to “listen between the lines” is known as “conversational implicature”.
Implicature vs implication. By conversational implicature, “Last night I saw John at a restaurant with a woman” suggests that John was with a woman other than his wife, because if the woman had been his wife, the speaker would have said so. However, by logical implication, the woman could have been John’s wife, since all wives are women.
Speak clearly, in plain English.
People naturally avoid ambiguity and obscurity of expression in a conversation. Using words and phrases that are familiar help reduce cognitive load. When it comes to word choice, if you wouldn’t say it, neither should your persona.