Distinguish facts from decision thresholds

The idea

Evidence estimates what may be true; a decision rule determines what action follows. Two people can agree about a probability yet reasonably choose different actions because their costs, benefits, responsibilities, or acceptable risks differ.

Worked example

A community theater estimates a one-in-five chance that an outdoor event will be disrupted. Renting a tent costs 200 units. Canceling after rain would lose 2,000 units, ignoring other consequences. Under these simplified assumptions, expected disruption loss is 400 units, so a 200-unit tent can be attractive even though dry weather is more likely. A volunteer who calls the tent a prediction of rain has confused the action threshold with the forecast.

Use it carefully

Expected-value arithmetic is an aid, not a complete moral theory. Severe harms, unequal burdens, cash constraints, and uncertain estimates may change the choice. State which consequences are counted and which are excluded. Revisit the threshold when the costs or evidence change. A cautious action does not prove danger was likely, and a good outcome does not prove the original decision process was sound.

RETRIEVE. REASON. REMEMBER.

Knowledge check.

Choose one answer for each question, then check your reasoning.