Model Selection Strategy #
Choosing the right foundation model for your application is a critical decision that impacts cost, performance, capabilities, and operational requirements.
Pattern Description #
This pattern provides a structured approach to selecting appropriate foundation models based on your specific requirements and constraints.
Key Considerations #
1. Capability Requirements #
- Task Domain: What tasks must the model perform? (text generation, code generation, image creation, etc.)
- Quality Bar: What level of output quality is acceptable?
- Specialized Knowledge: Does the model need domain-specific knowledge?
- Reasoning Ability: How complex is the reasoning required?
- Instruction Following: How precise must the model follow instructions?
2. Operational Constraints #
- Latency Requirements: What response time is acceptable?
- Throughput Needs: How many requests per minute must the system handle?
- Cost Sensitivity: What is the budget for model inference?
- Data Privacy: Can data be sent to external APIs or must processing be done on-premise?
- Deployment Environment: What compute resources are available?
3. Implementation Options #
Cloud API-based Models #
- Examples: OpenAI GPT-4, Anthropic Claude, Google Gemini
- Advantages: No infrastructure to manage, continuously improved, easy to integrate
- Disadvantages: Higher per-token costs, potential vendor lock-in, data leaves your environment
Self-hosted Models #
- Examples: Llama 2, Mistral, Falcon
- Advantages: Fixed costs, data privacy, customization control
- Disadvantages: Requires infrastructure management, potentially lower capabilities
Decision Framework #
- Start with capability requirements to create a shortlist
- Filter by operational constraints
- Consider hybrid approaches (multiple models for different functions)
- Evaluate top candidates with representative test cases
- Calculate total cost of ownership for final candidates
- Make selection with consideration for future flexibility
Implementation Example #
# Example model router that selects between models based on task complexity
def select_model(task_description, input_length, importance):
if importance == "critical" and input_length > 1000:
return "gpt-4"
elif complexity_score(task_description) > 0.7:
return "claude-2"
else:
return "mistral-7b-instruct"