role prompting

Role prompting is telling the model to answer as if it were a particular person or expert: act as a patient maths tutor, or you are a senior copy editor. By naming a role, you pull in a whole bundle of expectations at once, the vocabulary, the level of detail, the tone, that the model associates with that kind of speaker. It is a quick way to set style and stance without spelling out every rule.

It works because the model learned from text written by many kinds of authors, so a role acts like a pointer into that range, making the language of, say, a friendly tutor more likely than that of a terse manual. Used well, it shapes how an answer is delivered. Used carelessly, it is overrated: telling a model you are a world expert does not give it knowledge it never had, and it will not make facts more accurate. Treat role prompting as a control for voice and framing, and lean on examples, context, and clear instructions for the substance.