📝 Session 4: HyDE Implementation Guide¶
📝 PARTICIPANT PATH CONTENT Prerequisites: Complete 🎯 Observer path in Session 4 main content Time Investment: 60-90 minutes Outcome: Working HyDE system for semantic gap bridging
Learning Outcomes¶
After completing this implementation guide, you will:
- Build complete HyDE query enhancement systems
- Implement query type classification and templates
- Create hypothetical document generation workflows
- Develop enhanced embedding creation methods
Complete HyDE System Implementation¶
Step 1: Query Type Classification System¶
Build intelligent query classification to select appropriate enhancement templates:
def _classify_query_type(self, query: str) -> str:
"""Classify query type for appropriate HyDE template selection."""
classification_prompt = f"""
Classify the following query into one of these categories:
1. factual - Questions seeking specific facts or information
2. procedural - Questions asking how to do something
3. analytical - Questions requiring analysis or comparison
4. creative - Questions requiring creative responses
Query: {query}
Return only the category name:
"""
Classification Strategy: Using the LLM to automatically categorize queries enables appropriate template selection for generating relevant hypothetical documents.
try:
response = self.llm_model.predict(classification_prompt).strip().lower()
if response in self.hyde_templates:
return response
except Exception as e:
print(f"Classification error: {e}")
# Default to factual
return 'factual'
Error Handling: Robust fallback to factual queries ensures system reliability even when classification fails.
Step 2: Query Type Templates¶
Create specialized templates for different query types to generate appropriate hypothetical documents:
Factual Query Template¶
def _factual_hyde_template(self, query: str) -> str:
"""Template for factual query types."""
return f"""
Write a detailed, informative document that answers: {query}
The document should:
- Provide specific facts and data points
- Include relevant context and background
- Use authoritative tone and precise language
- Cover multiple aspects of the topic
- Include examples where relevant
Document:
"""
Procedural Query Template¶
def _procedural_hyde_template(self, query: str) -> str:
"""Template for procedural query types."""
return f"""
Write a detailed how-to guide that explains: {query}
The guide should:
- Provide step-by-step instructions
- Include prerequisite requirements
- Mention common pitfalls and solutions
- Explain the reasoning behind each step
- Include tips for success
Guide:
"""
Analytical Query Template¶
def _analytical_hyde_template(self, query: str) -> str:
"""Template for analytical query types."""
return f"""
Write an analytical document that examines: {query}
The analysis should:
- Present multiple perspectives or approaches
- Compare and contrast different options
- Discuss pros and cons
- Provide evidence-based reasoning
- Draw insightful conclusions
Analysis:
"""
Template Design: Each template guides the LLM to generate documents that match the expected format and style for different query types.
Step 3: Hypothetical Document Generation¶
Implement the core document generation system with quality controls:
def _generate_hypothetical_documents(self, query: str,
query_type: str,
num_docs: int) -> List[Dict]:
"""Generate multiple hypothetical documents with variations."""
base_template = self.hyde_templates[query_type]
hypothetical_docs = []
for i in range(num_docs):
# Add variation to temperature for diversity
varied_temperature = self.temperature + (i * 0.1)
varied_temperature = min(varied_temperature, 1.0)
Document Variation Strategy: Generating multiple hypothetical documents with different temperature settings creates diverse perspectives that increase retrieval coverage.
try:
# Generate hypothetical document
prompt = base_template(query)
# Use varied temperature for diversity
doc_text = self.llm_model.predict(
prompt,
temperature=varied_temperature
)
hypothetical_docs.append({
'document': doc_text.strip(),
'temperature': varied_temperature,
'variation': i + 1,
'word_count': len(doc_text.split()),
'quality_score': self._assess_document_quality(doc_text, query)
})
print(f"Generated hypothetical document {i+1}/{num_docs}")
except Exception as e:
print(f"Error generating document {i+1}: {e}")
continue
Generation Process: Each iteration creates a hypothetical document using the query-appropriate template with temperature variation for diverse outputs.
# Sort by quality score for best results
hypothetical_docs.sort(key=lambda x: x['quality_score'], reverse=True)
return hypothetical_docs
Step 4: Document Quality Assessment¶
Implement quality scoring to rank generated hypothetical documents:
def _assess_document_quality(self, document: str, query: str) -> float:
"""Assess the quality of a generated hypothetical document."""
quality_prompt = f"""
Rate the quality of this hypothetical document for answering the query.
Consider relevance, completeness, and accuracy.
Query: {query}
Document: {document[:500]}...
Rate from 0.0 to 1.0 where:
1.0 = Excellent, comprehensive answer
0.5 = Adequate, partial answer
0.0 = Poor, irrelevant answer
Return only a number:
"""
Quality Assessment: LLM-based quality scoring enables intelligent ranking of hypothetical documents for optimal enhancement.
try:
response = self.llm_model.predict(quality_prompt).strip()
quality_score = float(response)
return max(0.0, min(1.0, quality_score))
except:
return 0.5 # Default score if assessment fails
Step 5: Enhanced Embedding Creation¶
Create optimized embeddings that combine original queries with quality-weighted hypothetical documents:
def _create_enhanced_embeddings(self, query: str,
hypothetical_docs: List[Dict]) -> Dict:
"""Create enhanced embeddings combining query and hypothetical docs."""
# Original query embedding
original_embedding = self.embedding_model.encode([query])[0]
# Hypothetical document embeddings
hyde_texts = [doc['document'] for doc in hypothetical_docs]
hyde_embeddings = self.embedding_model.encode(hyde_texts)
# Calculate quality-based weights
weights = self._calculate_document_weights(hypothetical_docs)
# Weighted combination of hypothetical embeddings
weighted_hyde = np.average(hyde_embeddings, axis=0, weights=weights)
Weighted Averaging: Quality-based weighting ensures higher-quality hypothetical documents have more influence on the final embedding representation.
# Combine original query with weighted hypotheticals
# Give more weight to original query to preserve intent
combined_embedding = (0.3 * original_embedding +
0.7 * weighted_hyde)
# Normalize the combined embedding
combined_embedding = combined_embedding / np.linalg.norm(combined_embedding)
return {
'original': original_embedding,
'hyde_embeddings': hyde_embeddings,
'weighted_hyde': weighted_hyde,
'combined': combined_embedding,
'weights': weights
}
Step 6: Weight Calculation System¶
Implement sophisticated weighting for optimal embedding combination:
def _calculate_document_weights(self, hypothetical_docs: List[Dict]) -> List[float]:
"""Calculate weights for hypothetical documents based on quality."""
quality_scores = [doc['quality_score'] for doc in hypothetical_docs]
# Softmax normalization for weights
exp_scores = np.exp(np.array(quality_scores))
weights = exp_scores / np.sum(exp_scores)
return weights.tolist()
Softmax Normalization: Creates normalized weights that emphasize high-quality documents while maintaining mathematical consistency.
Step 7: Confidence Assessment¶
Add confidence scoring to evaluate enhancement effectiveness:
def _calculate_enhancement_confidence(self, enhanced_embeddings: Dict) -> float:
"""Calculate confidence score for the enhancement process."""
original = enhanced_embeddings['original']
combined = enhanced_embeddings['combined']
# Calculate similarity between original and enhanced
similarity = np.dot(original, combined) / (
np.linalg.norm(original) * np.linalg.norm(combined)
)
# Higher similarity indicates conservative enhancement
# Lower similarity indicates more aggressive transformation
confidence_score = 1.0 - abs(similarity - 0.7) # Target 0.7 similarity
return max(0.0, min(1.0, confidence_score))
Confidence Scoring: Measures the balance between original query preservation and enhancement transformation.
Testing Your HyDE Implementation¶
Test the complete system with different query types:
# Test the HyDE system
enhancer = HyDEQueryEnhancer(llm_model, embedding_model)
# Test factual query
factual_result = enhancer.enhance_query_with_hyde(
"What is the capital of France?",
query_type='factual'
)
# Test procedural query
procedural_result = enhancer.enhance_query_with_hyde(
"How do I deploy a Docker container?",
query_type='procedural'
)
# Test analytical query
analytical_result = enhancer.enhance_query_with_hyde(
"What are the pros and cons of microservices?",
query_type='analytical'
)
print("Enhancement Results:")
print(f"Factual confidence: {factual_result['confidence_score']}")
print(f"Procedural confidence: {procedural_result['confidence_score']}")
print(f"Analytical confidence: {analytical_result['confidence_score']}")
Integration with Vector Search¶
Connect your HyDE system to your existing vector search infrastructure:
def search_with_hyde(self, query: str, vector_store, top_k: int = 10):
"""Perform enhanced search using HyDE."""
# Generate enhanced embedding
hyde_result = self.enhance_query_with_hyde(query)
enhanced_embedding = hyde_result['enhanced_embedding']
# Search with enhanced embedding
enhanced_results = vector_store.similarity_search_by_vector(
enhanced_embedding, k=top_k
)
# Also search with original query for comparison
original_results = vector_store.similarity_search(query, k=top_k)
return {
'enhanced_results': enhanced_results,
'original_results': original_results,
'hyde_metadata': hyde_result,
'improvement_score': self._calculate_improvement(
enhanced_results, original_results, query
)
}
Enhanced Search Integration: Combining HyDE enhancement with your existing vector search infrastructure provides improved retrieval while maintaining compatibility.
Practice Exercises¶
- Template Optimization: Create custom templates for domain-specific queries
- Quality Metrics: Implement advanced quality assessment methods
- Performance Testing: Compare HyDE results with traditional search
- Error Handling: Add comprehensive error handling and fallback mechanisms
🧭 Navigation¶
Previous: Session 3 - Advanced Patterns →
Next: Session 5 - Type-Safe Development →