Running Experiments

Running Experiments

An OPTIONAL step — only use when the best approach is genuinely uncertain. Prototype 2-3 distinct approaches with real code, measure them honestly, then recommend one based on evidence.

Iron Law: an experiment is real measured code, or it is not an experiment

Every approach you compare must be actually built and run. You may never estimate, reason about, or "fill in" an approach's result — not even the one everyone is "sure" is slower. A comparison with one side measured and the other assumed is an opinion with a number stapled to one half; do not present it as an experiment, and never let it be cited as one in a design doc. If you genuinely cannot build an approach, say so and label the claim an unverified assumption — never dress it up as a benchmark.

Interaction mode

This skill leans Collaborative by default. For the full Collaborative-vs-Direct protocol and override rules, see the Interaction Modes reference in the ai-research-workflows:using-research-workflows skill.

Starting the skill

If no question is given, enter Collaborative mode and ask what to compare and why.

If a question is provided, look for matching context in docs/rse/specs/ (glob docs/rse/specs/{research,plan}-*.md, then legacy .agents/{research,plan}-*.md) and read any relevant documents fully before proceeding.

Process

Step 1: Gather context

• Read all referenced research/plan documents completely.
• From those docs, identify: the problem, constraints, codebase patterns, and integration points.
• Clarify the specific, measurable question the experiment must answer.

Step 2: Define hypothesis

State the question, what is being compared, and why the decision matters.

Identify 2-3 distinct approaches. More than 3 makes comparison difficult; fewer than 2 is not an experiment. "JWT HS256 vs RS256" is a configuration difference, not an architectural one — approaches must be architecturally distinct.

Define success criteria for each: how will you know if it works?

Step 3: Run experiments

For each approach:

1. Describe the approach — pros, cons, complexity rating (Low/Medium/High).

2. Write and isolate prototype code — actually write code, do not theorize. Isolate it in a temporary branch (git checkout -b experiment-<slug>) OR a scratch directory (mkdir -p .experiments/<slug>). Document where the code lives.

3. Execute — run tests, benchmarks, and integration checks with real commands:

   python experiment_jwt.py
   time python benchmark.py
   pytest tests/test_experiment.py -v
   

   For any performance claim, run each benchmark multiple times and report variance (not a single number), fix seeds, and hold the environment and input constant across approaches — you are comparing the design, not the noise. Capture the conditions per ai-research-workflows:ensuring-reproducibility.

4. Record observations honestly — successes and failures both. Include performance metrics, complexity assessment (lines of code, dependencies, integration points), and maintainability notes. Failed experiments are valuable; document them.

Step 4: Compare and recommend

Create a comparison matrix across key dimensions (performance, complexity, maintainability, integration ease, test coverage). Then:

**Recommended Approach:** [Name]

**Reasoning:** [Specific evidence from experiments]

**Why Not Others:**
- **Approach X:** [Evidence-based reason]
- **Approach Y:** [Evidence-based reason]

**Caveats:** [Conditions where this might not apply]

Identify conditions under which an alternative approach would be preferable.

Step 5: Generate experiment document

Derive a slug from the experiment question (lowercase, hyphenated).

Read the template: assets/experiment-template.md

Fill all sections: goal, hypothesis, approaches, actual code snippets with file paths, execution commands and outputs, observations (positive and negative), comparison matrix, key insights, recommendation, and conditions for alternatives.

Save to docs/rse/specs/experiment-<slug>.md (create docs/rse/specs/ if needed).

Step 6: Present findings

Summarize concisely:

# Experiment Complete: [Topic]

Documented at `docs/rse/specs/experiment-[slug].md`.

Approaches: [Approach 1] / [Approach 2] / [Approach 3]

Key findings: [2-3 bullets]

Recommendation: Use [Approach] because [primary reason].
Trade-offs accepted: [list]

Would you like to proceed, or explore further?

When NOT to experiment

Skip experimentation when:

• The approach is obvious from existing codebase patterns.
• The decision is not technically risky.
• The cost of being wrong is low.
• You are overthinking a simple problem.

Example: the codebase already uses JWT everywhere — follow that pattern, no experiment needed.

Important guidelines

Keep experiments focused — test one architectural variable at a time; control for other factors.

Record ALL observations — negative results are data; document what was tried and why it was rejected.

Reference specific file paths — use path/to/file.ext:lines notation to show how prototypes integrate with existing code.

Cross-references

Experiments reference research and plan documents in docs/rse/specs/ (or legacy .agents/). Results inform the ai-research-workflows:iterating-plans and ai-research-workflows:planning-implementations skills. To make a chosen approach reproducible, use ai-research-workflows:ensuring-reproducibility.

Red flags — STOP, you're fabricating a comparison

Common Mistakes

• Theorizing instead of running code — describing what an approach "would probably do" without actually writing and executing a prototype produces opinions, not data; always run real commands.
• Estimating one side of the comparison — building the favored approach and assuming the other's result is not a head-to-head experiment; measure every approach you compare.
• Cherry-picking results — reporting only the winning approach's successes while omitting failures skews the comparison; document what was tried and why it was rejected for every approach.
• Approaches that are not meaningfully distinct — comparing two configuration variants (e.g., HS256 vs RS256) instead of architecturally different designs collapses into a config choice, not a real experiment.
• Running an experiment when the answer is already known — if the codebase already uses a pattern consistently, follow it; experimentation on settled questions wastes time and produces noise.

Quality checklist

Before completing, verify:

• All referenced research/plan docs read completely
• 2-3 architecturally distinct approaches tested
• Actual code written and executed for each approach
• Performance/behavior measured with real commands
• Observations include both successes and failures
• Comparison matrix objectively covers key dimensions
• Recommendation is clear with honest reasoning
• Trade-offs explicitly documented
• Conditions for alternative approaches identified
• Template used from assets/experiment-template.md
• Document saved to docs/rse/specs/experiment-<slug>.md
• Code snippets include file paths or locations