Few-shot prompting and conversation roles

Introduction to Claude Models

Nikhil Rangarajan

Data Scientist

Conversation roles with message format

Messages array simulates multi-turn conversations
Each message has a role
Follows specific response styles

messages = [
    {"role": "user", 
 "content": "What's the weather like?"},
    {"role": "assistant", 
 "content": "I don't have access to 
     current weather data. You might 
     want to check a weather app."},
    {"role": "user", 
 "content": "How's traffic downtown?"}]

response = client.messages.create(
    model="claude-sonnet-4-20250514",
    messages=messages)

Introduction to few shot prompting

Few-shot prompting teaches Claude through examples
User/assistant message pairs demonstrate desired behavior
Effective on new input

A user and an assistant

Understanding zero-shot vs few-shot vs one-shot

Zero-shot: Single prompt with no examples
One-shot: Single example provided before the task
Few-shot: Multiple examples showing the pattern
More examples generally improve consistency

Few-shot code example

messages = [{"role": "user", "content": "Translate to French: Hello"}] # Zero-shot

# One-shot  
messages = [{"role": "user", "content": "Translate to French: Good morning"},
    {"role": "assistant", "content": "Bonjour"},
    {"role": "user", "content": "Translate to French: Hello"}]

# Few-shot (multiple examples)
messages = [{"role": "user", "content": "Translate to French: Good morning"},
    {"role": "assistant", "content": "Bonjour"},
    {"role": "user", "content": "Translate to French: Thank you"},
    {"role": "assistant", "content": "Merci"},
    {"role": "user", "content": "Translate to French: Hello"}]

Practical few shot applications

Format consistency: Show desired output structure
Tone matching: Demonstrate specific communication style
Complex reasoning: Guide multi-step problem solving
Domain expertise: Teach specialized knowledge application

# Teaching email response format
messages = [{"role": "user", "content": "Customer complaint: Late delivery"},
    {"role": "assistant", "content": "Dear Customer,\n\nWe apologize for the delay. 
     We'll track your order and update you within 24 hours.
     \n\nBest regards,\nSupport Team"},
    {"role": "user", "content": "Customer complaint: Wrong item received"}]

Best practices for few-shot prompting

Prompting

Use 2-5 examples for most tasks
Ensure examples are high-quality and consistent
Vary examples to show pattern, not just repetition
Test with edge cases to verify robustness

Let's practice!

Introduction to Claude Models