Identify loaded language in historical accounts of the same event and explain how connotation, not just denotation, shapes a reader's judgment.
Denotation is a word's literal, dictionary meaning. Connotation is the emotional charge a word carries beyond that literal meaning. Loaded language uses words with strong connotations, positive or negative, to steer a reader's judgment without ever stating an opinion directly -- and it shows up constantly in accounts of the Crusades, an event fought and later described from very different sides.
Consider the capture of Jerusalem in 1099. Christian chronicles of the era often describe it using words like "liberation" or "deliverance" of the Holy City, and describe its defenders using harsh, dehumanizing terms. Arab chronicles of the same event use very different loaded language -- describing the arriving armies as foreign invaders rather than liberators. Both descriptions can refer to the exact same siege. The denotation (a city changed hands by force) barely differs; the connotation (was this a rescue or an invasion?) differs completely.
Mastery looks like: They can identify specific loaded words in a text and explain the difference between the denotation and the connotation those words carry.
Common stumbles: Noticing that two accounts disagree without being able to point to the specific loaded words creating that disagreement.