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Memory System A/B Test Design

Version: 1.0.0 Date: 2025-11-03 Status: Design Complete Goal: Prove (or disprove) that Neo4j memory provides measurable value vs SQLite memory


Executive Summary

Test Objective

Quantitatively compare Neo4j-based memory system vs SQLite-based memory system to determine:

  1. Does memory provide measurable benefit? (vs no memory baseline)
  2. Does Neo4j provide measurable benefit over SQLite? (if memory proves valuable)
  3. What are the specific improvements? (time, quality, error prevention)

Key Design Principles

Following project philosophy:

  • Ruthless Simplicity: Measure what matters, ignore vanity metrics
  • Measurement First: Establish baseline before optimization
  • Statistical Rigor: Proper sample sizes, confidence intervals, p-values
  • Fair Comparison: Control for confounding variables
  • Transparent Reporting: Show raw data and statistical analysis

Expected Outcomes

Based on research findings, we hypothesize:

  • Memory vs No Memory: 20-35% improvement in repeat task efficiency
  • Neo4j vs SQLite: Minimal difference at <100k records, 10-30% improvement at scale
  • Break-even Point: 4-6 weeks after implementation

1. Test Methodology

1.1 Three-Way Comparison

We will test three configurations:

Configuration Description Purpose
Control No memory system (current baseline) Establish if memory provides value
SQLite SQLite-based memory (Phase 1 implementation) Measure basic memory effectiveness
Neo4j Neo4j-based memory (Phase 3 implementation) Measure graph capabilities value

1.2 Test Structure

┌─────────────────────────────────────────────────────────────┐
│ Phase 1: Baseline Establishment (No Memory)                 │
│ - Run 10 scenarios × 5 iterations = 50 baseline runs        │
│ - Collect: time, errors, quality scores                     │
│ - Establish statistical baseline                            │
└─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐
│ Phase 2: SQLite Memory Testing                              │
│ - Run same 10 scenarios × 5 iterations = 50 SQLite runs     │
│ - Collect same metrics                                      │
│ - Compare to baseline with statistical tests                │
└─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐
│ Phase 3: Neo4j Memory Testing (ONLY if Phase 2 succeeds)    │
│ - Run same 10 scenarios × 5 iterations = 50 Neo4j runs      │
│ - Collect same metrics                                      │
│ - Compare to SQLite with statistical tests                  │
└─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐
│ Phase 4: Analysis & Decision                                │
│ - Statistical significance testing                          │
│ - Effect size calculations                                  │
│ - Cost-benefit analysis                                     │
│ - Final recommendation                                      │
└─────────────────────────────────────────────────────────────┘

1.3 Fair Comparison Requirements

To ensure valid comparison:

  1. Same Agent Prompts: Identical agent definitions across all configurations
  2. Same Scenarios: Identical task definitions and inputs
  3. Same Environment: Same machine, same Claude model, same dependencies
  4. Isolated Runs: Clear memory/state between test runs
  5. Randomization: Scenario order randomized to prevent ordering effects
  6. Blinding: Automated test harness (no human bias in execution)

2. Test Scenarios

2.1 Scenario Selection Criteria

Each scenario must:

  1. Representative: Common real-world coding task
  2. Repeatable: Can be run multiple times with consistent setup
  3. Memory-Relevant: Benefits from learning/context
  4. Measurable: Clear success/failure criteria
  5. Time-Bounded: Completes in 2-10 minutes

2.2 Scenario Catalog

Scenario 1: Repeat Authentication Implementation

Type: Learning from repetition Expected Memory Benefit: HIGH (50-70% time reduction on second attempt)

Task: Implement JWT authentication for REST API

First Iteration:
- No memory available
- Agent explores options, makes decisions
- Records: implementation pattern, common pitfalls

Second Iteration (different project):
- Memory available from first iteration
- Should reuse proven pattern
- Should avoid previous pitfalls

Metrics:
- Time to complete (seconds)
- Number of errors encountered
- Code quality score (automated analysis)
- Pattern reuse (did agent reference previous solution?)

Scenario 2: Cross-Project Validation Pattern

Type: Pattern transfer Expected Memory Benefit: MEDIUM (25-40% improvement)

Task: Implement input validation for user registration endpoint

Context:
- Project A: Implement email validation
- Project B: Implement similar validation (different field)

With Memory:
- Should recognize similar validation pattern
- Should reuse regex/logic approach
- Should avoid repeated edge case bugs

Metrics:
- Code similarity to proven pattern
- Edge cases covered
- Time to implementation
- Test coverage

Scenario 3: Error Resolution Learning

Type: Error pattern recognition Expected Memory Benefit: HIGH (60-80% faster resolution)

Task: Debug "TypeError: 'NoneType' object is not subscriptable"

First Occurrence:
- Agent investigates multiple possibilities
- Eventually finds: missing null check
- Records: error signature → solution pattern

Second Occurrence:
- Same error signature in different context
- Should quickly identify null check issue
- Should apply proven solution

Metrics:
- Time to identify root cause
- Time to resolution
- Solution quality
- Memory pattern match accuracy

Scenario 4: API Design with Past Examples

Type: Design pattern application Expected Memory Benefit: MEDIUM (30-45% quality improvement)

Task: Design REST API for new domain entity

With Memory:
- Access to previous API designs
- See patterns that worked well
- Avoid anti-patterns from past

Without Memory:
- Make decisions from scratch
- May repeat previous mistakes

Metrics:
- API design consistency score
- Adherence to REST principles
- Error handling completeness
- Documentation quality

Scenario 5: Code Review with Historical Context

Type: Quality improvement Expected Memory Benefit: MEDIUM (40-55% more issues found)

Task: Review PR for security vulnerabilities

With Memory:
- Recall previous vulnerabilities found
- Check for similar patterns
- Apply learned security principles

Without Memory:
- Generic security checklist
- May miss patterns seen before

Metrics:
- Number of valid issues found
- False positive rate
- Critical issues caught
- Review thoroughness score

Scenario 6: Test Generation Pattern

Type: Procedural memory Expected Memory Benefit: MEDIUM (35-50% better coverage)

Task: Generate unit tests for authentication module

With Memory:
- Recall test patterns for auth
- Include edge cases from past
- Cover previously-missed scenarios

Metrics:
- Test coverage percentage
- Edge cases covered
- Test quality score
- Time to generate complete test suite

Scenario 7: Performance Optimization

Type: Optimization pattern recognition Expected Memory Benefit: LOW-MEDIUM (20-35% improvement)

Task: Optimize slow database query

With Memory:
- Recall previous optimization strategies
- Apply proven indexing patterns
- Avoid ineffective optimizations tried before

Metrics:
- Query performance improvement (%)
- Time to identify bottleneck
- Optimization approach quality

Scenario 8: Refactoring Legacy Code

Type: Refactoring strategy Expected Memory Benefit: MEDIUM (30-45% improvement)

Task: Refactor monolithic function into modular components

With Memory:
- Apply previous refactoring patterns
- Use proven module boundaries
- Avoid previous refactoring mistakes

Metrics:
- Cyclomatic complexity reduction
- Number of modules created
- Test coverage maintained
- Refactoring time

Scenario 9: Integration Error Resolution

Type: Integration debugging Expected Memory Benefit: HIGH (50-70% faster resolution)

Task: Debug failing integration test (external API timeout)

First Time:
- Investigate multiple hypotheses
- Check API docs, network, code
- Find: retry logic missing

With Memory:
- Recognize timeout pattern
- Quickly check retry logic
- Apply proven solution

Metrics:
- Debugging time
- Hypotheses explored
- Correct solution speed

Scenario 10: Multi-File Feature Implementation

Type: Complex feature with dependencies Expected Memory Benefit: MEDIUM (25-40% improvement)

Task: Implement user authentication feature (controller, service, tests, docs)

With Memory:
- Recall feature implementation patterns
- Use proven file organization
- Apply consistent naming conventions
- Include all necessary components from start

Metrics:
- Implementation completeness
- Code consistency score
- Number of revision cycles
- Total implementation time

2.3 Scenario Memory Pre-Seeding

Critical Decision: How to handle memory state for fair testing?

  • Approach: Each test run starts with empty memory
  • Pro: Fair comparison, no confounding variables
  • Con: Doesn't test long-term memory accumulation
  • Use Case: Baseline establishment, initial memory validation

Option B: Pre-Seeded Memory (For Phase 2)

  • Approach: Seed memory with N representative entries before test
  • Pro: Tests realistic memory state
  • Con: Requires careful seed data curation
  • Use Case: Testing memory retrieval effectiveness

Option C: Progressive Memory Building (For Phase 3)

  • Approach: Run scenarios sequentially, building memory over time
  • Pro: Tests real-world accumulation
  • Con: Later scenarios affected by earlier ones
  • Use Case: Long-term effectiveness testing

Decision: Use Option A for baseline comparison, then Option B for retrieval testing.


3. Metrics Collection

3.1 Primary Metrics (Objective)

These metrics are automatically collected by test harness:

3.1.1 Time Metrics

class TimeMetrics:
    execution_time: float          # Total task execution time (seconds)
    time_to_first_action: float   # Time until agent takes first action
    decision_time: float          # Time spent in decision-making
    implementation_time: float    # Time spent writing code

Collection Method: Timestamp at task start, action points, and completion.

3.1.2 Quality Metrics

class QualityMetrics:
    test_pass_rate: float         # Percentage of tests passing (0-1)
    code_complexity: int          # Cyclomatic complexity
    error_count: int              # Number of errors during execution
    revision_cycles: int          # Number of code revision iterations
    pylint_score: float           # Automated code quality score (0-10)

Collection Method: Run automated analysis tools on generated code.

3.1.3 Memory Usage Metrics

class MemoryMetrics:
    memory_retrievals: int        # Number of memory queries
    memory_hits: int              # Number of relevant memories found
    memory_applied: int           # Number of memories actually used
    retrieval_time: float         # Time spent retrieving memories (ms)

Collection Method: Instrument memory system with logging.

3.1.4 Output Metrics

class OutputMetrics:
    lines_of_code: int            # LOC generated
    files_modified: int           # Number of files changed
    test_coverage: float          # Test coverage percentage (0-100)
    documentation_completeness: float  # Doc completeness score (0-1)

Collection Method: Analyze generated artifacts.

3.2 Secondary Metrics (Qualitative)

These metrics require manual assessment (sample subset):

3.2.1 Decision Quality

class DecisionQuality:
    architecture_appropriateness: int    # 1-5 scale
    pattern_selection_quality: int       # 1-5 scale
    error_handling_completeness: int     # 1-5 scale
    edge_case_coverage: int              # 1-5 scale

Assessment Method: Expert review of 20% sample (10 runs), scoring rubric.

3.2.2 Pattern Recognition

class PatternRecognition:
    recognized_previous_solution: bool   # Did agent reference past work?
    adapted_pattern_appropriately: bool  # Was adaptation correct?
    avoided_previous_errors: bool        # Prevented repeated mistakes?

Assessment Method: Manual analysis of agent reasoning and decision logs.

3.3 Metric Collection Implementation

# Test harness will collect metrics automatically
class MetricsCollector:
    def __init__(self, scenario_id: str, config: str):
        self.scenario_id = scenario_id
        self.config = config  # "control", "sqlite", or "neo4j"
        self.metrics = {}
        self.start_time = None

    def start_collection(self):
        """Begin metric collection for a test run."""
        self.start_time = time.time()
        self.metrics = {
            "scenario_id": self.scenario_id,
            "config": self.config,
            "timestamp": datetime.now().isoformat(),
            "time": {},
            "quality": {},
            "memory": {},
            "output": {}
        }

    def record_time_metric(self, name: str, value: float):
        """Record a time-based metric."""
        self.metrics["time"][name] = value

    def record_quality_metric(self, name: str, value: Union[int, float]):
        """Record a quality metric."""
        self.metrics["quality"][name] = value

    def record_memory_metric(self, name: str, value: Union[int, float]):
        """Record a memory usage metric."""
        self.metrics["memory"][name] = value

    def record_output_metric(self, name: str, value: Union[int, float]):
        """Record an output metric."""
        self.metrics["output"][name] = value

    def finalize(self) -> dict:
        """Finalize and return collected metrics."""
        self.metrics["time"]["total_execution"] = time.time() - self.start_time
        return self.metrics

4. Statistical Analysis

4.1 Sample Size Calculation

Goal: Detect 20% improvement with 80% power at α=0.05

# Using standard power analysis
from scipy.stats import power
from statsmodels.stats.power import tt_ind_solve_power

# Expected effect size: 20% improvement
# Cohen's d ≈ 0.5 (medium effect)
# Power = 0.80
# Alpha = 0.05

sample_size = tt_ind_solve_power(
    effect_size=0.5,
    power=0.80,
    alpha=0.05,
    ratio=1.0,
    alternative='two-sided'
)

# Result: ~64 observations per group
# We'll use: 10 scenarios × 5 iterations = 50 per group
# This gives ~75% power (acceptable for initial testing)

Decision: 5 iterations per scenario = 50 total runs per configuration

This provides:

  • 75% power to detect 20% improvement
  • 95% confidence intervals
  • Reasonable time investment (~8-10 hours per configuration)

4.2 Statistical Tests

4.2.1 Primary Comparison: Paired T-Test

from scipy.stats import ttest_rel

def compare_configurations(baseline_times, treatment_times):
    """
    Compare execution times between configurations.

    Uses paired t-test because same scenarios run with different configs.
    """
    # Paired t-test (same scenarios, different conditions)
    t_statistic, p_value = ttest_rel(baseline_times, treatment_times)

    # Calculate effect size (Cohen's d for paired data)
    diff = np.array(treatment_times) - np.array(baseline_times)
    effect_size = np.mean(diff) / np.std(diff)

    # Calculate confidence interval
    conf_interval = stats.t.interval(
        0.95,
        len(diff) - 1,
        loc=np.mean(diff),
        scale=stats.sem(diff)
    )

    return {
        "t_statistic": t_statistic,
        "p_value": p_value,
        "effect_size": effect_size,
        "mean_diff": np.mean(diff),
        "conf_interval_95": conf_interval,
        "significant": p_value < 0.05
    }

4.2.2 Multiple Comparisons Correction

from statsmodels.stats.multitest import multipletests

def analyze_all_metrics(baseline_data, treatment_data, metrics):
    """
    Analyze multiple metrics with Bonferroni correction.

    Prevents false positives from multiple testing.
    """
    results = {}
    p_values = []

    for metric in metrics:
        baseline_values = [run[metric] for run in baseline_data]
        treatment_values = [run[metric] for run in treatment_data]

        result = compare_configurations(baseline_values, treatment_values)
        results[metric] = result
        p_values.append(result["p_value"])

    # Apply Bonferroni correction
    corrected = multipletests(p_values, alpha=0.05, method='bonferroni')

    for i, metric in enumerate(metrics):
        results[metric]["corrected_p_value"] = corrected[1][i]
        results[metric]["significant_corrected"] = corrected[0][i]

    return results

4.2.3 Effect Size Interpretation

Following Cohen's guidelines:

Effect Size ( d ) Interpretation Example
< 0.2 Negligible Not practically significant
0.2 - 0.5 Small Noticeable but minor improvement
0.5 - 0.8 Medium Substantial improvement
> 0.8 Large Major improvement

Decision Criteria:

  • Proceed with SQLite: Medium effect (d > 0.5) AND p < 0.05
  • Proceed with Neo4j: Medium effect (d > 0.5) AND p < 0.05 AND practical benefit > complexity cost

4.3 Confidence Intervals

Report 95% confidence intervals for all metrics:

def calculate_confidence_intervals(data, confidence=0.95):
    """Calculate confidence intervals for metrics."""
    results = {}

    for metric_name, values in data.items():
        mean = np.mean(values)
        sem = stats.sem(values)
        ci = stats.t.interval(
            confidence,
            len(values) - 1,
            loc=mean,
            scale=sem
        )

        results[metric_name] = {
            "mean": mean,
            "std": np.std(values),
            "ci_lower": ci[0],
            "ci_upper": ci[1],
            "ci_width": ci[1] - ci[0]
        }

    return results

4.4 Visualization

Generate comparison visualizations:

import matplotlib.pyplot as plt
import seaborn as sns

def plot_comparison(baseline, sqlite, neo4j, metric_name):
    """Generate box plot comparison."""
    data = pd.DataFrame({
        'Control (No Memory)': baseline,
        'SQLite Memory': sqlite,
        'Neo4j Memory': neo4j
    })

    plt.figure(figsize=(10, 6))
    sns.boxplot(data=data)
    plt.ylabel(metric_name)
    plt.title(f'{metric_name} Comparison Across Configurations')
    plt.savefig(f'comparison_{metric_name}.png')
    plt.close()

5. Baseline Establishment

5.1 Control Configuration Setup

class ControlConfiguration:
    """Configuration with no memory system."""

    def __init__(self):
        self.memory_enabled = False
        self.agents = load_agent_definitions()  # Standard agents

    def run_scenario(self, scenario):
        """Run scenario without memory."""
        # No memory retrieval
        # No memory storage
        # Pure agent execution
        return run_agent_task(scenario, memory=None)

5.2 Baseline Data Collection

Process:

  1. Run all 10 scenarios × 5 iterations = 50 baseline runs
  2. Collect all metrics for each run
  3. Calculate baseline statistics (mean, std, CI)
  4. Save baseline data for comparison

Expected Results:

{
  "baseline_statistics": {
    "execution_time": {
      "mean": 180.5,
      "std": 25.3,
      "ci_95": [175.2, 185.8]
    },
    "error_count": {
      "mean": 3.2,
      "std": 1.5,
      "ci_95": [2.8, 3.6]
    },
    "quality_score": {
      "mean": 7.5,
      "std": 0.8,
      "ci_95": [7.3, 7.7]
    }
  }
}

5.3 Baseline Documentation

Store baseline results in:

docs/memory/BASELINE_RESULTS.md

Include:

  • Raw data (JSON format)
  • Statistical summaries
  • Scenario-specific performance
  • Environmental context (machine specs, model version)

6. Test Harness Implementation

6.1 Architecture

scripts/memory_test_harness.py
├── Configuration Management
│   ├── ControlConfig (no memory)
│   ├── SQLiteConfig (SQLite memory)
│   └── Neo4jConfig (Neo4j memory)
├── Scenario Management
│   ├── ScenarioLoader (load scenario definitions)
│   ├── ScenarioRunner (execute scenarios)
│   └── ScenarioValidator (verify results)
├── Metrics Collection
│   ├── MetricsCollector (collect metrics)
│   ├── MetricsAggregator (aggregate across runs)
│   └── MetricsStorage (save to database)
├── Statistical Analysis
│   ├── StatisticalTests (t-tests, effect sizes)
│   ├── ConfidenceIntervals (calculate CIs)
│   └── MultipleComparisonsCorrection (Bonferroni)
└── Reporting
    ├── ReportGenerator (create comparison reports)
    ├── Visualization (generate plots)
    └── SummaryExporter (export results)

6.2 Core Interface

# scripts/memory_test_harness.py

class MemoryTestHarness:
    """Automated A/B test harness for memory systems."""

    def __init__(self, output_dir: str = "test_results"):
        self.output_dir = Path(output_dir)
        self.scenarios = self.load_scenarios()
        self.configurations = {
            "control": ControlConfiguration(),
            "sqlite": SQLiteConfiguration(),
            "neo4j": Neo4jConfiguration()
        }

    def run_full_test_suite(self):
        """Run complete A/B test suite."""
        print("=" * 70)
        print("MEMORY SYSTEM A/B TEST SUITE")
        print("=" * 70)

        # Phase 1: Baseline
        print("\n[Phase 1] Establishing baseline (no memory)...")
        baseline_results = self.run_configuration("control")
        self.save_results(baseline_results, "baseline")

        # Phase 2: SQLite
        print("\n[Phase 2] Testing SQLite memory...")
        sqlite_results = self.run_configuration("sqlite")
        self.save_results(sqlite_results, "sqlite")

        # Analyze Phase 2
        comparison_2 = self.compare_configurations(baseline_results, sqlite_results)
        self.save_comparison(comparison_2, "baseline_vs_sqlite")

        if comparison_2["proceed_recommendation"]:
            # Phase 3: Neo4j (only if Phase 2 successful)
            print("\n[Phase 3] Testing Neo4j memory...")
            neo4j_results = self.run_configuration("neo4j")
            self.save_results(neo4j_results, "neo4j")

            # Analyze Phase 3
            comparison_3 = self.compare_configurations(sqlite_results, neo4j_results)
            self.save_comparison(comparison_3, "sqlite_vs_neo4j")

        # Phase 4: Final Analysis
        print("\n[Phase 4] Generating final report...")
        self.generate_final_report()

    def run_configuration(self, config_name: str) -> List[dict]:
        """Run all scenarios for a configuration."""
        config = self.configurations[config_name]
        results = []

        for scenario in self.scenarios:
            print(f"  Running scenario: {scenario.name}")

            for iteration in range(5):  # 5 iterations per scenario
                print(f"    Iteration {iteration + 1}/5...", end="")

                # Run scenario
                result = self.run_single_test(config, scenario, iteration)
                results.append(result)

                print(f" Done ({result['time']['total_execution']:.1f}s)")

        return results

    def run_single_test(
        self,
        config: Configuration,
        scenario: Scenario,
        iteration: int
    ) -> dict:
        """Run a single test iteration."""
        # Initialize metrics collector
        collector = MetricsCollector(scenario.id, config.name)
        collector.start_collection()

        # Run scenario with configuration
        try:
            output = config.run_scenario(scenario)

            # Collect metrics from output
            self.collect_metrics_from_output(collector, output)

        except Exception as e:
            # Record failure
            collector.record_quality_metric("error_occurred", 1)
            collector.record_quality_metric("error_message", str(e))

        # Finalize and return metrics
        return collector.finalize()

    def compare_configurations(
        self,
        baseline: List[dict],
        treatment: List[dict]
    ) -> dict:
        """Compare two configurations statistically."""
        comparison = {}

        # Extract metrics for comparison
        metrics = ["execution_time", "error_count", "quality_score"]

        for metric in metrics:
            baseline_values = [r["time"]["execution_time"] if metric == "execution_time"
                              else r["quality"][metric] for r in baseline]
            treatment_values = [r["time"]["execution_time"] if metric == "execution_time"
                               else r["quality"][metric] for r in treatment]

            # Run statistical test
            comparison[metric] = self.statistical_test(baseline_values, treatment_values)

        # Determine recommendation
        comparison["proceed_recommendation"] = self.should_proceed(comparison)

        return comparison

    def should_proceed(self, comparison: dict) -> bool:
        """Determine if results justify proceeding."""
        # Check if improvement is statistically significant
        significant = comparison["execution_time"]["significant"]

        # Check if effect size is meaningful
        effect_size = abs(comparison["execution_time"]["effect_size"])
        meaningful = effect_size > 0.5  # Medium effect

        # Check if p-value is strong
        strong = comparison["execution_time"]["p_value"] < 0.01

        return significant and meaningful

    def generate_final_report(self):
        """Generate comprehensive comparison report."""
        report = FinalReportGenerator(self.output_dir)
        report.generate()

        print(f"\n{'=' * 70}")
        print(f"Final report saved to: {self.output_dir}/COMPARISON_RESULTS.md")
        print(f"{'=' * 70}")

6.3 Scenario Definition Format

# scenarios/01_repeat_authentication.yaml

id: repeat_authentication
name: Repeat Authentication Implementation
type: learning_from_repetition
expected_benefit: high
iterations: 5

description: |
  Implement JWT authentication for REST API.
  First iteration: no memory, explores options.
  Second iteration: should reuse proven pattern.

first_run:
  task: "Implement JWT authentication for REST API with user login endpoint"
  project: "test_project_auth_1"
  expected_files:
    - "auth/jwt_handler.py"
    - "auth/user_model.py"
    - "tests/test_auth.py"

  success_criteria:
    - "Tests pass"
    - "JWT token generation works"
    - "Token validation works"

second_run:
  task: "Implement JWT authentication for REST API with user login endpoint"
  project: "test_project_auth_2"
  expected_files:
    - "authentication/jwt.py"
    - "models/user.py"
    - "tests/test_jwt.py"

  success_criteria:
    - "Tests pass"
    - "JWT token generation works"
    - "Token validation works"
    - "Reuses pattern from first run (memory)"

metrics:
  primary:
    - execution_time
    - error_count
    - pattern_reuse_detected

  secondary:
    - code_quality_score
    - test_coverage
    - documentation_completeness

7. Reporting Format

7.1 Comparison Report Structure

# Memory System Comparison Results

**Test Date**: 2025-11-03
**Configurations Tested**: Control, SQLite, Neo4j
**Total Test Runs**: 150 (50 per configuration)

## Executive Summary

### Key Findings

- **Memory Benefit**: [YES/NO] - Memory provides [X]% improvement over no memory
- **Neo4j Benefit**: [YES/NO] - Neo4j provides [X]% improvement over SQLite
- **Statistical Confidence**: [HIGH/MEDIUM/LOW] - p-value: [X], effect size: [X]
- **Recommendation**: [PROCEED/STOP/ADJUST]

### Performance Summary

| Metric             | Control | SQLite | Neo4j | SQLite Δ | Neo4j Δ  |
| ------------------ | ------- | ------ | ----- | -------- | -------- |
| Avg Execution Time | 180s    | 120s   | 115s  | **-33%** | **-36%** |
| Avg Error Count    | 3.2     | 1.5    | 1.2   | **-53%** | **-63%** |
| Avg Quality Score  | 7.5     | 8.3    | 8.5   | **+11%** | **+13%** |

## Detailed Analysis

### 1. Execution Time

**Baseline (Control)**: 180.5s (±25.3s)
**SQLite**: 120.2s (±18.7s)
**Neo4j**: 115.3s (±17.2s)

**Statistical Test (Control vs SQLite)**:

- t-statistic: -12.34
- p-value: < 0.001 ✓ **Highly Significant**
- Effect size (Cohen's d): 0.82 (Large)
- 95% CI for difference: [-65.2, -55.4]s

**Interpretation**: SQLite memory reduces execution time by 33% with large effect size. This is a **substantial and statistically significant improvement**.

[... continue for each metric ...]

## Scenario-Specific Results

### Scenario 1: Repeat Authentication

- Control: 210s ± 30s
- SQLite: 95s ± 12s (**-55%**)
- Neo4j: 90s ± 11s (**-57%**)
- **Memory Impact**: Very High

[... continue for each scenario ...]

## Cost-Benefit Analysis

### Development Cost

- SQLite implementation: 3 weeks (1 FTE)
- Neo4j migration: +2 weeks (1 FTE)

### Expected Benefits

- Time saved per developer: 2-4 hours/week
- Error reduction: 50-70%
- Break-even: 4-6 weeks

### Recommendation

**PROCEED with SQLite implementation**

- Provides substantial benefit (33% time reduction)
- Statistically significant (p < 0.001)
- Justifies development investment

**DEFER Neo4j migration**

- Incremental benefit over SQLite is small (3%)
- Current scale doesn't justify complexity
- Revisit when >100k memory entries

7.2 Visualization Examples

Generate plots for report:

  1. Execution Time Comparison (box plot)
  2. Error Count Comparison (box plot)
  3. Quality Score Comparison (violin plot)
  4. Scenario-Specific Performance (grouped bar chart)
  5. Memory Hit Rate Over Time (line chart)
  6. Statistical Power Analysis (power curve)

8. Decision Criteria

8.1 Go/No-Go Decision Matrix

Criteria Threshold Weight
Statistical Significance p < 0.05 Required
Effect Size Cohen's d > 0.5 Required
Practical Improvement > 20% time reduction High
Error Reduction > 30% fewer errors High
Quality Improvement > 10% quality increase Medium
Cost-Benefit Ratio ROI > 0 within 6 months High

8.2 Decision Rules

Proceed with SQLite if:

  • Statistical significance (p < 0.05) ✓
  • Medium-to-large effect size (d > 0.5) ✓
  • Practical benefit > 20% ✓
  • No significant negative side effects ✓

Proceed with Neo4j if:

  • Statistical significance vs SQLite (p < 0.05) ✓
  • Meaningful improvement > 15% over SQLite ✓
  • Complexity justified by benefit ✓
  • Current scale warrants graph database (>100k nodes) ✓

Stop/Adjust if:

  • No statistical significance (p > 0.05)
  • Negligible effect size (d < 0.2)
  • Negative impact on other metrics
  • High false positive rate in memory retrieval

9. Limitations and Threats to Validity

9.1 Internal Validity Threats

  1. Learning Effects: Later iterations may benefit from agent "learning" independent of memory
  2. Mitigation: Randomize scenario order, use fresh agent instances

  3. Scenario Selection Bias: Chosen scenarios may favor memory systems

  4. Mitigation: Include diverse scenario types, some less memory-dependent

  5. Metric Gaming: Agents may optimize for measured metrics

  6. Mitigation: Use multiple independent metrics, manual quality reviews

9.2 External Validity Threats

  1. Generalization: Test scenarios may not represent all real-world usage
  2. Mitigation: Select scenarios based on user research, validate with users

  3. Scale: Test scale (50 runs) may not reflect production scale

  4. Mitigation: Run longer-term trials after initial validation

  5. Environment: Controlled test environment differs from real usage

  6. Mitigation: Follow up with in-situ testing with real users

9.3 Construct Validity Threats

  1. Metric Validity: Measured metrics may not capture all aspects of quality
  2. Mitigation: Combine automated metrics with expert review

  3. Memory Quality: Test may not assess memory correctness (false positives)

  4. Mitigation: Manual review of memory retrieval accuracy

10. Implementation Timeline

Week 1: Test Harness Development

  • Day 1-2: Design test harness architecture
  • Day 3-5: Implement core harness functionality
  • Weekend: Review and refinement

Week 2: Scenario Implementation

  • Day 1-2: Implement 5 scenarios
  • Day 3-4: Implement remaining 5 scenarios
  • Day 5: Validate scenarios, dry runs

Week 3: Baseline Testing

  • Day 1-3: Run baseline tests (Control configuration)
  • Day 4: Analyze baseline results
  • Day 5: Document baseline, prepare for Phase 2

Week 4: SQLite Testing

  • Day 1-3: Run SQLite memory tests
  • Day 4: Statistical analysis, comparison to baseline
  • Day 5: Phase 2 decision gate meeting

Week 5: Neo4j Testing (if Phase 2 successful)

  • Day 1-3: Run Neo4j memory tests
  • Day 4: Statistical analysis, comparison to SQLite
  • Day 5: Generate final report

Week 6: Analysis and Reporting

  • Day 1-2: Comprehensive analysis
  • Day 3-4: Create visualizations, write report
  • Day 5: Present findings, make final decision

Total Duration: 6 weeks (assuming no major issues)


11. Success Criteria

Minimum Success Criteria (Required)

  1. ✓ Statistical significance (p < 0.05)
  2. ✓ Medium effect size (d > 0.5)
  3. ✓ Practical improvement (>20% time reduction)
  4. ✓ No major negative side effects

Stretch Success Criteria (Desired)

  1. ✓ Large effect size (d > 0.8)
  2. ✓ Strong significance (p < 0.01)
  3. ✓ Error reduction >50%
  4. ✓ Quality improvement >15%
  5. ✓ Positive user feedback

12. Risk Mitigation

Risk 1: Insufficient Sample Size

Mitigation: Run additional iterations if initial results show high variance

Risk 2: Confounding Variables

Mitigation: Strictly control environment, document all variables

Risk 3: Test Harness Bugs

Mitigation: Extensive testing of harness before main test runs

Risk 4: Long Test Duration

Mitigation: Parallelize test runs where possible, use automation


Conclusion

This A/B test design provides a rigorous, fair, and scientifically sound methodology for evaluating memory system effectiveness. Key strengths:

  1. Three-way comparison: Control, SQLite, Neo4j
  2. Statistical rigor: Proper sample sizes, multiple tests correction
  3. Fair comparison: Controlled variables, randomization
  4. Practical focus: Measures what matters (time, errors, quality)
  5. Phased approach: Decision gates prevent over-investment

Next Steps:

  1. Review and approve design
  2. Implement test harness (Week 1-2)
  3. Run baseline tests (Week 3)
  4. Make data-driven decisions at each gate

Document Status: ✅ Design Complete - Ready for Implementation Author: Architect Agent Review Date: 2025-11-03