LithosAnanake/docs/working/papers/REPRODUCIBILITY.md

Reproducibility: One-Command Experiment Reproduction

Version: 1.0 Date: 2025-12-14 Purpose: Idiot-proof single-command reproduction of experimental claims

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THE PROMISE

One command. No ambiguity. Exact results.

If you run the command below and don't get our claimed results, report it as a bug.

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I. QUICK START (30 seconds)

The One Command

git clone https://github.com/rajames440/StarForth.git && \
cd StarForth && \
make fastest && \
./build/amd64/fastest/starforth --doe --config=C_FULL

Expected Output:

=== StarForth DoE Run ===
Configuration: C_FULL (all loops enabled)
Tests: 780+ passed
Cache hit rate: 17.39 ± 0.00%
Runtime: ~7-10 ms ± 60%
=== DoE Complete ===

If you see this: ✅ Reproduction successful

If you don't: ❌ See Section VIII (Troubleshooting)

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II. EXACT REPRODUCTION ENVIRONMENT

Canonical Environment (Docker)

Purpose: Eliminate ALL environmental differences

Command:

# Clone repository
git clone https://github.com/rajames440/StarForth.git
cd StarForth

# Build Docker image
docker build -t starforth-exact -f Dockerfile.exact-reproduction .

# Run exact reproduction
docker run --rm \
  -v $(pwd)/reproduction-results:/results \
  starforth-exact

# Verify checksums
cd reproduction-results/
sha256sum -c EXPECTED_CHECKSUMS.txt

Expected Output:

run_01.csv: OK
run_02.csv: OK
...
run_30.csv: OK
summary.txt: OK

If ALL checksums match: ✅ Bit-for-bit exact reproduction

If ANY checksum differs: ❌ Report to GitHub issues

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III. COMMIT HASH REFERENCE

Exact Commit for Reproduction

Commit SHA: 8133787 (ONTOLOGY.md baseline)

Verification:

git clone https://github.com/rajames440/StarForth.git
cd StarForth
git checkout 8133787

# Verify you're on correct commit
git log -1 --format="%H %s"
# Expected: 8133787 ONTOLOGY.md

Why This Matters: Code changes over time. This commit is the reproduction baseline.

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IV. DEPENDENCY LOCK FILE

Exact Versions (Ubuntu 22.04)

File: docker/reproduction.lock

os: ubuntu:22.04
kernel: 6.2.0-39-generic
gcc: 11.4.0-1ubuntu1~22.04
make: 4.3-4.1build1
glibc: 2.35-0ubuntu3.8
binutils: 2.38-4ubuntu2.6

Installation (if not using Docker):

# Ubuntu 22.04 only
sudo apt-get update
sudo apt-get install -y \
  gcc-11=11.4.0-1ubuntu1~22.04 \
  make=4.3-4.1build1 \
  git=1:2.34.1-1ubuntu1.10

# Verify versions
gcc-11 --version | head -1
make --version | head -1

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V. HARDWARE SPECIFICATION

Reference Hardware

Original Experiments Conducted On:

• CPU: Intel Xeon Gold 6154 @ 3.00GHz (18 cores)
• RAM: 128GB DDR4-2666 ECC
• Storage: Samsung 970 PRO NVMe 1TB
• Motherboard: Supermicro X11DPi-NT
• Cooling: Noctua NH-U12DX i4 (active cooling, < 60°C under load)

Minimum Requirements:

• CPU: x86_64 with AVX2 support
• RAM: 16GB
• Storage: 10GB free space
• OS: Linux kernel 5.x+

Expected Variability:

Metric	Tolerance	Reason
Cache CV	0.00% (exact match)	Algorithmic determinism
Runtime	±50%	Hardware differences acceptable
Convergence rate	±10%	CPU-dependent optimization gains

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VI. ENVIRONMENT CONFIGURATION

CPU Settings (Critical for Determinism)

Disable Frequency Scaling:

# Set CPU governor to performance mode
sudo cpupower frequency-set -g performance

# Disable Turbo Boost (Intel)
echo 1 | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

# Verify
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
# All should say "performance"

Disable ASLR (Address Space Layout Randomization):

# Disable ASLR for deterministic memory layout
echo 0 | sudo tee /proc/sys/kernel/randomize_va_space

# Verify
cat /proc/sys/kernel/randomize_va_space
# Should be 0

Set Process Affinity:

# Pin to single core to avoid migration
taskset -c 0 ./build/amd64/fastest/starforth --doe

Why These Settings:

• No frequency scaling: Eliminates timing variance from CPU throttling
• No Turbo Boost: Consistent clock speed across runs
• No ASLR: Deterministic memory addresses
• CPU affinity: No cache invalidation from core migration

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VII. FULL EXPERIMENT REPRODUCTION

90-Run Experiment (3 configs × 30 runs)

Time Required: ~4 hours (includes warmup, inter-run delays)

Command:

# Run full experimental protocol
make reproduce-full-experiment

# This script does:
# 1. Build all configurations
# 2. Run 30 trials × 3 configs = 90 runs
# 3. Generate summary statistics
# 4. Compare to expected results
# 5. Output report

Expected Output Files:

reproduction-results/
├── C_NONE/
│   ├── run_01.csv
│   ├── run_02.csv
│   └── ...
├── C_CACHE/
│   └── ...
├── C_FULL/
│   └── ...
├── summary.txt          # Statistical summary
├── convergence.png      # Visualization
└── CHECKSUMS.sha256     # Verification file

Automatic Validation:

# After completion, script runs validation
make validate-reproduction

# Checks:
# - All 90 runs completed
# - Cache CV = 0.00% for all configs
# - Convergence p < 0.001 for C_FULL
# - Checksums match expected values

# Output: PASS or FAIL with specific deviations

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VIII. TROUBLESHOOTING

Error 1: "make: command not found"

Cause: Build tools not installed

Fix:

sudo apt-get install build-essential
make --version  # Verify installation

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Error 2: "gcc-11: command not found"

Cause: Wrong GCC version

Fix:

# Install GCC 11
sudo apt-get install gcc-11

# Update alternatives
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 100

gcc --version  # Should be 11.x

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Error 3: "Cache CV = 12.5%, expected 0.00%"

Cause: ⚠️ CRITICAL - Determinism broken

Diagnosis:

# Check for random number generators
grep -r "rand(" src/
# Should return nothing

# Check ASLR
cat /proc/sys/kernel/randomize_va_space
# Should be 0

# Check CPU governor
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# Should be "performance"

If all checks pass: Report as bug (GitHub issue with logs)

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Error 4: "Runtime = 150 ms, expected ~8 ms"

Cause: Debug build instead of optimized build

Fix:

# Ensure you built "fastest" target
make clean
make fastest  # NOT "make debug"

# Verify optimization flags
grep CFLAGS Makefile | grep -- "-O3"
# Should see -O3 -march=native -flto

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Error 5: "Docker build fails"

Cause: Docker version too old

Fix:

# Update Docker
sudo apt-get update
sudo apt-get install docker.io

docker --version  # Should be 20.x+

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Error 6: "Segmentation fault"

Cause: Possible memory corruption or compiler bug

Diagnosis:

# Run under valgrind
valgrind --leak-check=full ./build/amd64/fastest/starforth --doe

# Check for memory errors
# If found: Report to GitHub issues

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IX. QUICK VERIFICATION CHECKLIST

Before Reporting Failure:

• Commit: On 8133787 or later
• Build: Used make fastest (not debug)
• GCC: Version 11.x
• CPU Governor: Set to performance
• Turbo Boost: Disabled
• ASLR: Disabled (/proc/sys/kernel/randomize_va_space = 0)
• Process Affinity: Pinned to single core
• Tests: All 780+ tests pass (make test)
• Single Run: Cache CV = 0.00% in at least one run

If ALL checks pass and you still can't reproduce: File GitHub issue.

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X. STATISTICAL VALIDATION SCRIPT

Automated Result Verification

Command:

# After running experiments
Rscript scripts/validate_reproduction.R \
  --input reproduction-results/ \
  --expected docs/archive/phase-1/Reference/physics_experiment/experiment_summary.txt \
  --output validation_report.txt

# Report includes:
# - Cache CV comparison (expected: 0.00%)
# - Convergence p-value (expected: p < 0.001)
# - Effect size (expected: Cohen's d ≈ 5.08)
# - PASS/FAIL verdict

Expected Output:

=== Reproduction Validation Report ===
Cache CV:
  Expected: 0.00%
  Observed: 0.00%
  Status: ✅ PASS

Convergence:
  Expected: p < 0.001
  Observed: p = 0.00012
  Status: ✅ PASS

Effect Size:
  Expected: Cohen's d ≈ 5.08
  Observed: Cohen's d = 5.23
  Status: ✅ PASS (within ±10%)

OVERALL: ✅ REPRODUCTION SUCCESSFUL

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XI. RNG SEED VERIFICATION

Ensuring No Hidden Randomness

Test:

# Search for random number usage
grep -r "random\|rand\|srand" src/ include/

# Expected: No matches (deterministic code only)

If found: Check context. Only acceptable uses:

• Comments explaining determinism
• Test code for failure modes (see NEGATIVE_RESULTS.md)

Not acceptable:

• Production code using rand()
• Unseeded RNG usage

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XII. CROSS-PLATFORM REPRODUCTION

x86_64 (Intel/AMD)

Status: ✅ Fully supported and validated

Command:

make fastest ARCH=x86_64
./build/x86_64/fastest/starforth --doe

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ARM64 (Raspberry Pi, Apple M1)

Status: ⚠️ Experimental (convergence magnitude may differ)

Command:

make fastest ARCH=aarch64
./build/aarch64/fastest/starforth --doe

Expected Differences:

• Cache CV: Still 0.00% (determinism holds)
• Convergence: May be 18-30% (CPU-dependent)
• Runtime: Slower absolute values (ARM vs x86)

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RISC-V

Status: ⚠️ Untested (future work)

Hypothesis: Should work (architecture-agnostic algorithm)

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XIII. CHECKSUMS FOR VERIFICATION

Generate Your Own

After running experiments:

# Generate checksums of your results
cd reproduction-results/
find . -type f -name "*.csv" -exec sha256sum {} \; | sort > MY_CHECKSUMS.txt

# Compare to expected
diff MY_CHECKSUMS.txt ../docs/EXPECTED_CHECKSUMS.txt

If checksums match: ✅ Bit-for-bit exact reproduction

If checksums differ: Check:

1. GCC version (must be 11.x)
2. Build flags (use make fastest)
3. Floating-point mode (we use fixed-point Q48.16, no FP variance)

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XIV. LONG-TERM REPRODUCIBILITY

Archival Package (Zenodo)

DOI: [TBD - Upload to Zenodo for permanent archive]

Contents:

• Source code (commit 8133787)
• Full 90-run dataset
• Docker container image
• Dependency lock file
• This reproduction guide

Purpose: Ensure reproducibility 10+ years from now when Ubuntu 22.04 is obsolete.

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XV. CONTACT FOR HELP

If You're Stuck

Email: rajames440@gmail.com (Robert A. James)

Subject: [StarForth Replication] <brief issue>

Include:

• OS and kernel version (uname -a)
• GCC version (gcc --version)
• Build command used
• Error logs (attach as .txt)
• Expected vs. observed results

Response Time: Within 48 hours

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XVI. REPRODUCTION SUCCESS RATE

Goal: >90% Success Rate

We track:

• Number of replication attempts
• Success vs. failure rate
• Common failure modes

Public Dashboard (planned): https://starforth.org/replication-stats

Current Status (as of 2025-12-14):

• Attempts: 1 (original)
• Successes: 1
• Rate: 100% (baseline)

Update: After you replicate, report your result (success or failure) to update this metric.

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XVII. CONTINUOUS INTEGRATION

Automated Reproduction Testing

GitHub Actions (planned):

# .github/workflows/reproducibility-check.yml
name: Reproducibility CI

on: [push, pull_request]

jobs:
  reproduce:
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/checkout@v3
      - name: Build
        run: make fastest
      - name: Run DoE
        run: ./build/amd64/fastest/starforth --doe --config=C_FULL
      - name: Validate
        run: |
          if [ "$(grep 'Cache CV:' output | awk '{print $3}')" != "0.00%" ]; then
            echo "FAIL: Cache CV not 0.00%"
            exit 1
          fi

Purpose: Catch regressions that break reproducibility.

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XVIII. SUMMARY

Three Ways to Reproduce:

1. Quick (30 seconds): make fastest && ./starforth --doe
2. Docker (exact, 5 minutes): docker run starforth-exact
3. Full (4 hours): make reproduce-full-experiment

If you can't reproduce:

1. Check troubleshooting section
2. Verify environment configuration
3. Run validation script
4. Contact us if still stuck

If you CAN reproduce:

1. Report success (GitHub issue or email)
2. Cite our work if you use it
3. Consider extending to your use case

Bottom Line: We've removed every excuse for non-reproduction. If it doesn't work, we want to know immediately.

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License: See ./LICENSE