A conversation can appear to be going well right up until somebody tries to go backward. Two people are talking easily, each response seems to follow from the one before it, and they may even be agreeing. Then one person says, “Wait, that's not quite what I meant.”
Sometimes the correction is easy. The other person asks what they missed, the earlier interpretation changes and the conversation continues from there. Nothing particularly dramatic happened; one model of what the other person meant was replaced by a better one. Other times the correction feels strangely expensive. The person has to defend why they're correcting themselves, earlier statements get quoted back as though consistency matters more than clarification, and both people begin spending more effort protecting the structure of the exchange than examining whatever they were originally trying to understand.
They may still eventually agree, which is one reason I'm no longer sure agreement tells us very much about whether a conversation worked. Agreement is simply a conclusion two people happen to share, and they can reach it through careful examination, social pressure, exhaustion, misunderstanding, politeness or coincidence. Two people can also understand one another remarkably well and remain in genuine disagreement.
The more interesting question is whether the conversation can survive revision. Can I tell you that you've misunderstood me without making the previous twenty minutes collapse? Can you change your mind without needing to pretend you never held the earlier position? Can either of us introduce information that complicates the emerging explanation? If we can, the conversation still has somewhere to go.
I've sometimes used the word “alignment” for this, although I think I was asking that word to carry too much. Alignment can sound as though two people have achieved some deeper shared state beneath their explicit disagreement. We don't need to claim that. What we can observe is whether the interaction remains revisable.
That matters because conversation is full of compression. I say something, you interpret it, and your response necessarily depends on a smaller model of what I meant than everything I might have meant. I hear your response and do the same thing. Most of the time this works astonishingly well, which is why we can have ordinary conversations without stopping every few seconds to define our terms.
Sometimes the compression is wrong. Tone gets interpreted as intent. Fluency gets interpreted as understanding. Familiar language makes two people think they're using a word in the same way when they aren't. A quick “yes” gets carried forward as agreement with a much larger proposition than the person intended.
None of those mistakes is especially dangerous while correction remains cheap. The trouble begins when the conversation builds on the misunderstanding faster than the misunderstanding can be repaired. Every additional exchange adds structure above the original error, so correcting it eventually means changing more than one interpretation. We have to reconsider everything subsequently built upon it.
This can produce a peculiar kind of conversation in which the exchange remains fluent while becoming progressively less accurate. Both people are responding intelligently, the sentences make sense and the reasoning may even be internally coherent. They're simply no longer talking about quite the same thing.
Fluency isn't enough to tell us whether that has happened, and neither is discomfort. A useful conversation can become uncomfortable because somebody has encountered evidence they don't like. Clarification can sound defensive because sometimes it is defensive. A pause can indicate careful thought, confusion, annoyance or nothing at all. No single signal gives us privileged access to the state of the interaction.
What we can do is leave room to test our interpretations. “Is that what you meant?” “I think I carried that farther than you