Why is shared knowledge a dangerous assumption?
A guest says they know the card game, so the people at the table deal them in. They recognise the cards and follow the turns without help. Nobody thinks an explanation is needed.
At the end of the first round, the guest counts the score differently. In the version they learned, a particular card carries a penalty. At this table, it does not. A choice that looked careless to the other players was sensible under the rule the guest believed they were using.
The mistake was not assuming that the guest knew anything. They did know the game. It was assuming that this meant knowing the same version in every detail.
A Spark from The Vision
It is misleading to assume that a person knows the same as you about anything in life.
In How much a person knows, Innocent describes expecting too much from someone in a venture because he assumed they shared his knowledge. He also remembers underestimating what other people knew. Both mistakes led him towards taking more time to find out, through conversation and actual situations, rather than deciding from an impression.
At the card table, the difference can be settled before the next round. Someone explains the local scoring and asks whether any other rules differ. The guest describes another variation, and the group agrees which one they will use. They now share something that, a few minutes earlier, everyone merely assumed was shared.
There is no need to begin again with an explanation of what a card is or how to take a turn. That would overlook the knowledge the guest has already shown. Good explanation meets the actual gap; it does not turn one unfamiliar detail into evidence that a person knows nothing.
The same difficulty becomes more consequential when people are relying on one another’s work. A colleague may know how to prepare a report but not which figures were revised yesterday. Another may understand the figures better than you do but be unfamiliar with how this group records a correction. General experience and local information are different forms of knowledge.
Asking about the task can reveal that difference more accurately than asking whether someone is competent. “Which version are you working from?” gives a person something definite to answer. Their answer might show that you need to explain a change. It might show that they have information you missed.
Silence cannot settle this for you. Someone may hear a familiar instruction and reasonably believe there is nothing to ask. They cannot request an explanation of a difference they do not yet know exists. That is why checking only after a disappointing result can produce an unfair accusation of carelessness.
Of course, conversation does not reveal everything a person knows. Actual work may expose another difference later. The aim is to leave enough room for that discovery to change the expectation, instead of forcing the person to carry an expectation built on missing information.
At the table, the next round can test the newly agreed rules. The guest may still make a poor choice. But the players will be judging a choice made within a genuinely shared game, rather than mistaking a different rule for a lack of ability.
Related lessons
AI-generated from Innocent Mwatsikesimbe's writing.
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