intermediate⏱45 minLesson 3 of 5

Advanced Prompting Techniques

Master Chain-of-Thought, Few-Shot, Structured Outputs, Self-Consistency, and Tree-of-Thoughts prompting.

Advanced Prompting Techniques

Why Advanced Techniques?

Basic prompting works for simple tasks, but complex reasoning, structured outputs, and specialized problems require more sophisticated approaches. Each technique in this lesson addresses a specific limitation of basic prompting — from improving step-by-step reasoning to enabling multi-path exploration.

When Basic Prompting Falls Short

Limitation	Basic Attempt	Advanced Technique
Multi-step math/logic problems	Model guesses final answer	Chain-of-Thought: step-by-step reasoning
Unfamiliar output formats	Model invents wrong format	Few-Shot: examples guide the model
Need machine-readable output	Inconsistent text responses	Structured Outputs: JSON mode
Single answer may be wrong	No way to verify correctness	Self-Consistency: majority voting
Complex exploration/planning	Model follows one path	Tree-of-Thoughts: multiple branches

Chain-of-Thought (CoT) Prompting

Chain-of-Thought prompting encourages the model to break down problems into intermediate reasoning steps. Rather than jumping directly to an answer, the model "shows its work," which both improves accuracy and makes errors easier to debug.

CoT Reasoning Flow

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

Full CoT Reasoning Sequence

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

CoT Example

Q: A store has 15 apples. They sell 4, then receive a delivery that doubles
their current apple count. How many apples do they have now?

Let's think step by step:
1. Start with 15 apples
2. After selling 4: 15 - 4 = 11 apples
3. Delivery doubles current count: 11 * 2 = 22 apples

Answer: 22

ℹ️Note

Simply adding "Let's think step by step" to your prompt can significantly improve reasoning performance on math and logic problems.

⚠️Warning

CoT token costs: Chain-of-Thought can increase output tokens by 3-10x because the model generates intermediate reasoning steps before the final answer. For cost-sensitive applications, consider using shorter prompts like "Explain briefly" or limiting max_tokens. For a production system processing millions of requests, this token multiplier directly affects your bottom line.

CoT in Code

python

from openai import OpenAI

client = OpenAI()

# Without CoT
response_direct = client.chat.completions.create(
    model="gpt-4",
    messages=[
        {"role": "user", "content": "If a shirt costs $40 and is on sale for 25% off, plus 8% tax, what's the final price?"}
    ],
    temperature=0.0
)
print("Direct:", response_direct.choices[0].message.content)

# With CoT
response_cot = client.chat.completions.create(
    model="gpt-4",
    messages=[
        {"role": "user", "content": """If a shirt costs $40 and is on sale for 25% off, plus 8% tax, what's the final price?

Let's think step by step:"""}
    ],
    temperature=0.0
)
print("\nCoT:", response_cot.choices[0].message.content)

CoT Variants

Variant	Description	Best For
Zero-shot CoT	Just add "Let's think step by step"	Quick reasoning improvement
Few-shot CoT	Provide example reasoning chains	Consistent format, harder problems
Structured CoT	Require numbered steps or bullet format	Debugging, audit trails
Multi-prompt CoT	Ask for reasoning, then answer in separate calls	Complex problems needing verification

Few-Shot and Multi-Shot Prompting

Few-shot prompting provides examples in the prompt to guide the model's behavior.

Technique	Examples Provided	Best For
Zero-Shot	0 examples	Simple tasks, common patterns
Few-Shot	1-5 examples	Specific formats, novel tasks
Multi-Shot	5+ examples	Complex patterns, fine-tuning alternative

Few-Shot Example: Sentiment Analysis

Classify the sentiment as POSITIVE, NEGATIVE, or NEUTRAL.

Example 1:
Review: "This movie was amazing, best I've seen all year!"
Sentiment: POSITIVE

Example 2:
Review: "Terrible service, never coming back."
Sentiment: NEGATIVE

Example 3:
Review: "The restaurant was on 5th street."
Sentiment: NEUTRAL

Now classify:
Review: "Product works as described, nothing exceptional."
Sentiment:

💡Tip

Choosing the right examples: Select examples that cover the range of expected inputs. Include edge cases and ambiguous examples. Poorly chosen examples (e.g., all positive sentiment when the test set has mixed sentiment) bias the model. Also, order matters — models tend to be influenced most by the last example (recency bias).

Few-Shot in Code

python

from openai import OpenAI

client = OpenAI()

# Few-shot examples
examples = [
    {"review": "This movie was amazing, best I've seen all year!", "sentiment": "POSITIVE"},
    {"review": "Terrible service, never coming back.", "sentiment": "NEGATIVE"},
    {"review": "The restaurant was on 5th street.", "sentiment": "NEUTRAL"},
]

def few_shot_classify(review_text: str, examples: list[dict]) -> str:
    prompt = "Classify the sentiment as POSITIVE, NEGATIVE, or NEUTRAL.\n\n"
    for i, ex in enumerate(examples, 1):
        prompt += f"Example {i}:\nReview: \"{ex['review']}\"\nSentiment: {ex['sentiment']}\n\n"
    prompt += f"Now classify:\nReview: \"{review_text}\"\nSentiment:"
    
    response = client.chat.completions.create(
        model="gpt-4",
        messages=[{"role": "user", "content": prompt}],
        temperature=0.0
    )
    return response.choices[0].message.content.strip()

test_review = "Product works as described, nothing exceptional."
print(few_shot_classify(test_review, examples))

Structured Outputs (JSON Mode)

Many LLMs support structured output formats, critical for programmatic integration.

python

from openai import OpenAI
import json

client = OpenAI()

response = client.chat.completions.create(
    model="gpt-4-turbo-preview",
    messages=[
        {"role": "system", "content": "Extract customer data and return as JSON."},
        {"role": "user", "content": """
        Extract info from this email:
        "Hi, I'm John Smith from Acme Corp. My phone is 555-0123.
        I'd like to order 10 units of the PRO plan at $99/month."
        """}
    ],
    response_format={"type": "json_object"}  # JSON mode enabled
)

# Parse the structured output
result = json.loads(response.choices[0].message.content)
print(json.dumps(result, indent=2))

Expected Output:

json

{
  "customer": {
    "name": "John Smith",
    "company": "Acme Corp",
    "phone": "555-0123"
  },
  "order": {
    "product": "PRO plan",
    "quantity": 10,
    "price": 99,
    "billing_cycle": "monthly"
  }
}

💡Tip

JSON mode validation: Always validate JSON outputs before using them in production. Use json.loads() with try/except to catch malformed JSON. Consider using Pydantic models for schema validation in Python applications.

JSON Schema Validation

python

import json
from typing import Optional
from pydantic import BaseModel, Field, ValidationError

class Customer(BaseModel):
    name: str
    company: str
    phone: Optional[str] = None

class Order(BaseModel):
    product: str
    quantity: int = Field(gt=0)
    price: float = Field(gt=0)
    billing_cycle: str

class ExtractionResult(BaseModel):
    customer: Customer
    order: Order

# Parse and validate API output
raw_json = '{"customer": {"name": "John Smith", "company": "Acme Corp"}, "order": {"product": "PRO plan", "quantity": 10, "price": 99, "billing_cycle": "monthly"}}'

try:
    validated = ExtractionResult(**json.loads(raw_json))
    print(f"Validated: {validated.model_dump_json(indent=2)}")
except ValidationError as e:
    print(f"Validation failed: {e}")

Structured Outputs with Other Providers

python

# Anthropic Claude - structured output via system prompt
import anthropic

client = anthropic.Anthropic()
response = client.messages.create(
    model="claude-3-opus-20240229",
    max_tokens=1000,
    system="You extract data to JSON. Only output valid JSON, no other text.",
    messages=[
        {"role": "user", "content": "Extract: John, Acme Corp, 555-0123, 10 units PRO plan $99/mo"}
    ]
)
print(response.content[0].text)

Self-Consistency

Self-Consistency generates multiple reasoning paths and selects the most frequent answer. It's like asking three experts separately and taking the majority vote — diverse reasoning paths reduce the chance that any single mistake determines the final answer.

Generate 3 different solutions to this problem, then pick the most common answer:

Problem: A train travels at 60 mph for 2 hours, then 80 mph for 1 hour.
What's the average speed?

Solution 1:
- Distance 1: 60 * 2 = 120 miles
- Distance 2: 80 * 1 = 80 miles
- Total: 200 miles in 3 hours
- Average: 200/3 = 66.67 mph

Solution 2:
- Average formula = total distance / total time
- Total distance = (60*2) + (80*1) = 200
- Total time = 3
- 200/3 = 66.67 mph

Solution 3:
- Just average the speeds: (60+80)/2 = 70 mph

Most common answer: 66.67 mph (appears 2 times)

Self-Consistency in Code

python

from openai import OpenAI
from collections import Counter

client = OpenAI()

def self_consistency(problem: str, n_paths: int = 3, temperature: float = 0.7) -> str:
    """Generate n reasoning paths and return the most frequent answer."""
    answers = []
    
    for i in range(n_paths):
        response = client.chat.completions.create(
            model="gpt-4",
            messages=[
                {"role": "user", "content": f"{problem}\n\nLet's think step by step:"}
            ],
            temperature=temperature,  # Higher temp for diverse paths
        )
        answers.append(response.choices[0].message.content)
        print(f"\nPath {i+1}:\n{answers[-1]}")
    
    # Extract final answers (simplified - production would use regex/NER)
    # In practice you'd use a final aggregation prompt
    # For now, demonstrate the concept
    return answers

problem = "A train travels at 60 mph for 2 hours, then 80 mph for 1 hour. What's the average speed?"
results = self_consistency(problem, n_paths=3)

Tree-of-Thoughts (ToT)

Tree-of-Thoughts explores multiple reasoning paths simultaneously, like a decision tree. Unlike CoT which follows one reasoning chain, ToT branches out, evaluates each branch, and either continues promising paths or prunes dead ends.

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

Tree-of-Thoughts Branching Flowchart

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

⚠️Warning

Self-Consistency and Tree-of-Thoughts require multiple API calls, significantly increasing cost and latency. Only use when single-call techniques aren't sufficient.

ToT Prompt Template

I want you to solve this problem using Tree-of-Thoughts reasoning.

Problem: {problem}

Instructions:
1. First, generate {num_branches} different initial approaches to this problem
2. For each approach, think through the first step
3. Evaluate each approach — which seems most promising?
4. For the most promising approach, continue developing it
5. Repeat: explore, evaluate, focus, until you reach an answer

Start by listing {num_branches} different ways to approach this problem:

Technique Comparison

Technique	Complexity	Best Use Case	Performance Gain	Token Cost
Chain-of-Thought	Low	Math, logic, multi-step problems	+20-50% on reasoning	2-5x increase
Few-Shot	Low	Classification, format matching	+10-30% vs zero-shot	1-2x (example tokens)
JSON Mode	Low	API integration, structured data	Critical for reliability	Minimal (format instruction)
Self-Consistency	Medium	Voting on multiple outputs	+5-15% vs single CoT	3-10x (multiple responses)
Tree-of-Thoughts	High	Complex search/exploration	+25-60% on hard problems	5-20x (many branches)

When to Use Each Technique

Scenario	Recommended Technique	Why
Math word problem	CoT	Simple step-by-step works best
Classify customer emails	Few-Shot	Examples clarify ambiguous categories
Extract data for database	JSON Mode	Machine-readable output required
Critical medical diagnosis	Self-Consistency + CoT	Safety requires majority voting
Novel puzzle/game strategy	Tree-of-Thoughts	Need to explore multiple approaches
Summarize a document	CoT (if complex) or Zero-Shot	Simpler is usually better

📌Important

Technique stacking: These techniques are not mutually exclusive. You can combine CoT with Few-Shot (provide example reasoning chains), use Self-Consistency with JSON Mode, or use ToT with structured outputs. Stacking techniques can compound benefits — but also compound token costs.

Practice Questions

Practice Question

A data analyst needs the LLM to extract customer information from emails and return it in a machine-readable format for database insertion. Which technique should they use?

Practice Question

Adding the phrase "Let's think step by step" to a math problem prompt improves accuracy by encouraging the model to:

Practice Question

A sentiment analysis task requires the model to classify reviews as POSITIVE, NEGATIVE, or NEUTRAL. The prompt includes three labeled examples before asking the model to classify a new review. This approach is known as:

Practice Question

A research team needs to solve a novel logic puzzle that requires exploring different reasoning approaches simultaneously, like a decision tree. Which technique should they use?

Practice Question

What is the main trade-off when using Self-Consistency or Tree-of-Thoughts compared to simpler techniques?

Practice Question

A developer implements a system where the LLM first generates a reasoning chain, then produces a JSON output. What technique combination is this?

Practice Question

A team runs CoT on a simple classification task and sees accuracy decrease compared to zero-shot. What is the most likely explanation?

Practice Question

A production system processes 1M requests/month. Switching from zero-shot to CoT increases output tokens from 50 to 200 per request. At $0.03/1K tokens, what is the monthly cost increase?

Practice Question

A developer uses few-shot prompting with examples ordered: NEGATIVE, POSITIVE, NEUTRAL. The model misclassifies most test cases as NEUTRAL. What's the most likely cause?

Practice Question

A prompt engineer validates a JSON output with Pydantic and catches a ValidationError. What should they do next?

✅Success

Key Takeaways:

Chain-of-Thought (CoT): "Let's think step by step" improves reasoning on math/logic
Few-Shot: Provide 1-5 examples to guide output format and style
Structured Outputs (JSON Mode): Critical for programmatic API integration
Self-Consistency: Generate multiple outputs and select the most frequent answer
Tree-of-Thoughts: Explore multiple reasoning branches like a decision tree
Advanced techniques cost more tokens—balance performance needs with cost
Techniques can be stacked: CoT + JSON, Few-Shot + CoT, Self-Consistency + Structured Outputs
For simple tasks, simpler techniques often outperform complex ones
Always validate structured outputs before production use

Progress60%

Prompt Frameworks: ABC, CO-STAR, RISEN

Prompt Optimization, Testing and Versioning

Course Content

1. Fundamentals of Prompt Engineering 2. Prompt Frameworks: ABC, CO-STAR, RISEN 3. Advanced Prompting Techniques 4. Prompt Optimization, Testing and Versioning 5. Prompt Safety, Injection Defense and Alignment