failing to make the distinction between personality traits and actual behaviour --or they impute personality from actions, when there can be any number of motives or personality traits that lead to an action: The knight betrays the lord to the lord's enemies. Is it because the knight is a coward? An ambitious schemer? Foolish? ... Theoretically we should know these things from the story, but since people can argue these points, it's very possible for a quiz creator to have a different notion of a character's personality from a quiz taker.