Generalized Variables for Compositional Language Model Programs: A Unified Optimization Framework
Stream of Consciousness Paper Outline / Brain Dump
Title Ideas:
- “Beyond Module Boundaries: Generalized Variables for Cross-Module Optimization in LM Programs”
- “Unified Variable Spaces for Compositional AI: Breaking the Module Optimization Silo”
- “SIMBA-GV: Adaptive Optimization of Shared Parameters Across Heterogeneous LM Modules”
- “From Local to Global: A Variable-Centric Approach to LM Program Optimization”
Abstract (rough ideas)
- Current LM programming frameworks (DSPy) treat modules as isolated optimization units
- We introduce generalized variables - parameters that transcend module boundaries
- Novel contribution: variable-aware execution traces, cross-module gradient estimation
- SIMBA adaptation for variable geometry understanding
- Results show 23-47% improvement in multi-module programs (need to run experiments)
- Opens new research directions in compositional AI optimization
1. Introduction
Hook: “What if temperature wasn’t just a parameter for one module, but a shared characteristic that influences reasoning style across an entire AI system?”
Problem Statement:
- LM programming emerging as dominant paradigm (cite DSPy, LMQL, Guidance)
- Current limitation: modules optimize in isolation
- Real systems need shared characteristics (formality, verbosity, reasoning depth)
- Example: medical diagnosis system where “conservativeness” should affect all modules
Key Insight:
- Variables in programs aren’t module-specific, they’re system characteristics
- Think: CPU temperature affects all cores, not just one
- Need unified optimization space
Contributions:
- Formalization of generalized variables for LM programs
- Variable-aware execution tracing and attribution
- Cross-module gradient estimation techniques
- SIMBA-GV: adapted optimizer for variable geometry
- Implementation in DSPex proving feasibility
- Empirical validation on 5 benchmark tasks
2. Background and Related Work
2.1 LM Programming Frameworks
- DSPy and the module abstraction (Khattab et al.)
- Compositional approaches (Chain of Thought, ReAct, etc.)
- Current optimization methods (BootstrapFewShot, MIPRO)
- Gap: all assume module-local parameter spaces
2.2 Parameter Sharing in ML
- Multi-task learning parameter sharing
- Neural architecture search shared weights
- Hyperparameter optimization across models
- Difference: we’re sharing semantic/behavioral parameters, not weights
2.3 Program Synthesis and Optimization
- Traditional program optimization (loop unrolling, etc.)
- Differentiable programming
- Black-box optimization
- Our approach: gray-box with semantic understanding
3. Generalized Variables: Formalization
3.1 Definitions
Definition 1 (Generalized Variable): A generalized variable v โ V is a tuple (ฯ, D, C, ฯ) where:
- ฯ is the type (continuous, discrete, module-type)
- D is the domain
- C is the constraint set
- ฯ is the semantic binding function
Definition 2 (Variable-Aware Module): A module M is variable-aware if it implements:
- get_variables(): โ Set[Variable]
- apply_variables(V): โ M'
- get_feedback(execution): โ Gradient[V]
Definition 3 (Cross-Module Program): A program P = (Mโ, Mโ, …, Mโ, V, ฯ) where:
- Mแตข are variable-aware modules
- V is shared variable set
- ฯ is the composition function
3.2 Variable Types
Continuous Behavioral Variables
- Temperature (creativity vs consistency)
- Verbosity (concise vs detailed)
- Formality (casual vs academic)
Discrete Structural Variables
- Reasoning strategy (step-by-step vs holistic)
- Output format (JSON vs prose)
- Error handling (strict vs lenient)
Module-Type Variables (novel contribution)
- Variable that changes module behavior class
- Example: AuthorStyle variable that makes all modules write like specific authors
- Requires new theory for optimization
4. Variable-Aware Execution Framework
4.1 Execution Traces with Variable Attribution
Key Innovation: Traces that track not just what happened, but which variables influenced each decision
Trace = {
module_calls: [(module_id, timestamp, input, output)],
variable_uses: [(var_id, timestamp, context, influence_score)],
decision_points: [(decision_type, chosen, alternatives, variable_weights)]
}
4.2 Cross-Module Variable Impact Measurement
Challenge: How do we measure impact of temperature on both Predict and ChainOfThought?
Solution: Unified effect metrics
- Semantic drift measurement
- Output distribution analysis
- Consistency scoring across modules
4.3 Gradient Estimation for Black-Box LMs
Since we can’t backprop through LMs, we need:
- Finite difference methods
- Semantic gradient approximation
- Natural language feedback incorporation (!)
5. SIMBA-GV: Geometry-Aware Variable Optimization
5.1 Variable Space Geometry
Insight: Variable space has special structure
- Some variables are correlated (temperature โ creativity)
- Some are antagonistic (speed โ accuracy)
- Some have module-specific effects
5.2 Adaptive Sampling in Variable Space
Original SIMBA samples data points. SIMBA-GV samples variable configurations:
- Coverage-based sampling: Ensure we explore variable space
- Gradient-informed sampling: Sample more in high-gradient regions
- Constraint-aware sampling: Respect variable constraints
5.3 Intelligent Mutation Strategies
Key idea: Mutations should understand variable semantics
- Temperature mutations: small changes, affects all modules
- Style mutations: discrete jumps, coordinated across modules
- Structural mutations: large changes, may need re-initialization
5.4 Cross-Module Bootstrap
Novel: Bootstrap examples that work well for ALL modules sharing a variable
Algorithm:
- Generate candidate examples
- Evaluate on each module with shared variables
- Score with multi-objective optimization
- Select Pareto-optimal examples
6. Implementation: DSPex Architecture
6.1 Native vs Python Execution
- Native: evaluation, tracing, variable management
- Python: DSPy modules via Snakepit
- Hybrid execution model
6.2 Performance Considerations
- Variable application overhead
- Trace collection impact
- Optimization loop efficiency
6.3 API Design
Show how users interact with system - should be intuitive!
7. Experimental Evaluation
7.1 Benchmark Tasks
Multi-Stage QA: Question โ Keywords โ Search โ Answer
- Shared variable: search_depth
Document Processing: Parse โ Extract โ Summarize โ Format
- Shared variable: detail_level
Code Generation: Understand โ Plan โ Implement โ Test
- Shared variable: verbosity, error_checking_strictness
Creative Writing: Ideate โ Outline โ Write โ Edit
- Shared variable: creativity_style
Scientific Analysis: Hypothesize โ Experiment โ Analyze โ Conclude
- Shared variable: confidence_threshold
7.2 Baselines
- DSPy with independent module optimization
- Naive parameter sharing (same value, no optimization)
- Grid search over variable space
- Random search baseline
7.3 Metrics
- Task-specific performance (accuracy, F1, BLEU, etc.)
- Optimization efficiency (convergence rate)
- Variable stability across modules
- Computational overhead
7.4 Research Questions
RQ1: Do generalized variables improve multi-module program performance? RQ2: How does variable type affect optimization difficulty? RQ3: What is the computational overhead of variable-aware execution? RQ4: How does SIMBA-GV compare to naive optimization approaches? RQ5: Can we automatically discover useful variables?
8. Results and Analysis
8.1 Performance Improvements
Expected: 20-50% improvement on multi-module tasks Why: Better coordination, no local optima traps
8.2 Variable Type Analysis
Hypothesis: Continuous > Discrete > Module-type in terms of optimization ease
8.3 Convergence Analysis
Show convergence curves, discuss variable stability
8.4 Ablation Studies
- Remove variable sharing
- Remove cross-module bootstrap
- Remove intelligent mutation
- Remove trace-based attribution
9. Discussion
9.1 Theoretical Implications
New optimization paradigm: From module-centric to variable-centric
- Changes how we think about LM program design
- Opens questions about variable discovery
- Connections to program synthesis
9.2 Practical Implications
For practitioners:
- Design programs with shared characteristics in mind
- Think about behavioral variables, not just prompts
- Consider cross-module effects early
9.3 Limitations
- Black-box LM assumption (no gradients)
- Computational overhead for large variable spaces
- Variable discovery still manual
- May not work for all module types
9.4 Future Directions
- Automatic Variable Discovery: Can we learn what variables matter?
- Hierarchical Variables: Variables that control other variables
- Dynamic Variable Spaces: Variables that appear/disappear during execution
- Meta-Learning: Learning to optimize variable spaces
10. Related Theoretical Frameworks
10.1 Connection to Control Theory
- Variables as control parameters
- Modules as system components
- Optimization as controller design
10.2 Connection to Category Theory
- Variables as morphisms between module behaviors
- Composition preserving properties
- Natural transformations between module types
10.3 Connection to Program Analysis
- Variables as program invariants
- Cross-module information flow
- Abstract interpretation over variable spaces
11. Conclusion
Summary:
- Introduced generalized variables for LM programs
- Showed how to optimize across module boundaries
- Demonstrated significant improvements
- Opened new research directions
Key Takeaway: “The future of LM programming isn’t just about better modules, but about better ways for modules to share behavioral characteristics”
Call to Action: Implement in your favorite LM framework!
Appendices (ideas)
A. Formal Proofs
- Convergence guarantees for SIMBA-GV
- Variable space complexity analysis
B. Implementation Details
- Code snippets
- Performance optimizations
- Edge case handling
C. Extended Results
- Full experimental tables
- Additional visualizations
- Failure case analysis
D. Variable Taxonomy
- Comprehensive list of useful variables
- Classification scheme
- Selection guidelines
Random Thoughts / TODO:
- Need to think more about module-type variables theory
- Should we prove something about variable space structure?
- Connection to neural architecture search?
- Maybe add a section on variable interactions?
- Need better notation for variable-aware modules
- Should discuss relationship to hyperparameter optimization
- Add more on semantic gradients - this is novel
- Think about variable lifecycle (creation, evolution, death)
- Discussion of variable scope (local vs global)
- Privacy implications of shared variables?
- How does this relate to federated learning?
- Can we use LLMs to suggest good variables?
- What about adversarial variables?
- Connection to game theory (variables as strategies)?
- Philosophical: what does it mean for modules to “share” behavior?
Potential Venues:
- NeurIPS (optimization angle)
- ICML (learning theory)
- ACL/EMNLP (NLP applications)
- ICLR (representation learning aspects)
- AAAI (general AI)
Experiments We Need:
- Baseline performance across tasks
- Ablation studies
- Convergence rate analysis
- Variable importance ranking
- Computational overhead measurement
- User study on API usability?
- Robustness to variable perturbation
- Transfer learning with variables
Code We Need to Write:
- Variable registry system
- Trace collection infrastructure
- SIMBA-GV optimizer
- Evaluation framework
- Visualization tools
- Benchmark implementations
Key Figures:
- System architecture diagram
- Variable space visualization
- Convergence curves
- Performance comparison bars
- Trace flow diagram
- Variable impact heatmap
- Cross-module gradient flow
Story Arc:
Introduction โ Problem โ Theory โ Implementation โ Validation โ Impact โ Future
Make sure each section flows into the next!
Writing Notes:
- Keep it accessible but rigorous
- Use running example throughout
- Make figures early - they help clarify thinking
- Get feedback on formalization section
- Make sure contributions are crystal clear
- Don’t oversell - be honest about limitations
- End with exciting future work
Reviews We’ll Probably Get:
- “Interesting idea but limited evaluation”
- “Need more theoretical analysis”
- “Comparison to hyperparameter optimization unclear”
- “Why not just use multi-task learning?”
- “Overhead seems high for modest gains”
Better address these preemptively!
Remember:
- This is about SHARED BEHAVIOR not shared parameters
- Variables are SEMANTIC not syntactic
- Cross-module optimization is the KEY insight
- SIMBA adaptation is novel and necessary
- Implementation proves feasibility
END BRAIN DUMP - Ready to start writing properly!