Fable
The master doesn't explain long rules—he just lays out three samples
A temporary assistant came to the calligraphy and painting shop, and the shopkeeper had no time to teach him all the rules from the beginning. On the first day, a customer wanted an inscription on a fan, and he wrote it like a stele inscription; a customer wanted a wedding card, and he wrote it like a bill.
The shopkeeper did not give a long theory, but brought out three sample drafts. The first was a birthday banquet invitation, solemn in tone; the second was an invitation card, concise in phrasing; the third was a reply to a return request, polite but not overpromising. Beside each was written how the customer asked and how the shop answered.
The assistant followed the sample draft and improved immediately. But he also mislearned: seeing that birthday banquet invitations had four-character auspicious phrases, he stuffed auspicious phrases into return letters too, making customers frown.
The shopkeeper added two more counterexamples to show which formats couldn't be copied freely, and placed the sample drafts before new tasks so the clerks could first see "this kind of question corresponds to this kind of answer." The samples didn't cover every case, but they gave him an imitable format, tone, and boundaries.
The next day a new customer arrived, asking to "write a short invitation for a housewarming banquet." The assistant had never seen the same topic before, but learned structure from the invitation samples and borrowed the appropriate tone from birthday banquet cards, and wrote a usable letter.
The shopkeeper also had the assistant explain what each sample draft could teach and what it could not. A birthday banquet invitation could teach the proper measure of congratulatory words, but that could not be learned into a return letter; a return letter could teach polite refusal, but that could not be learned into cold officialese. A few samples give direction, but they also leave misleading impressions.
A few days later, the shopkeeper brought in a new kind of customer: someone wanted an apology letter. The assistant searched all three sample drafts and could only piece together a half-convincing reply. Only then did the shopkeeper tell him that when samples are few, you must choose accurately and also know where the samples do not cover; otherwise, copying the cat and drawing the tiger will still go astray. Later, the shopkeeper regularly changed the sample drafts, including both common incoming letters and counterexamples that were easy to mislearn. A temporary assistant did not need to memorize the entire shop rulebook to quickly approximate the style; but he knew that beyond the samples, caution was still required.
The shopkeeper reminded him that a few sample drafts can quickly calibrate the approach, but they are not complete training. If the sample drafts are well chosen, the assistant immediately gets closer to the requirements; if the sample drafts are chaotic, he will also go astray. The most useful thing about a small number of examples is that they let a person see from context how to answer.