id: "skill_6cd1e0f4c6864ff89ff64d873441900f" name: "by-campaign-optimizer" display-name: "BY Campaign Optimizer (Active Learning)" short-description: "Trains a Random Forest on scored designs from prior rounds and proposes parameter adjustments for the next round. Use when a multi-round campaign has at least 10 scored designs and you need data-driven suggestions for thresholds, design counts, and feature targets." category: "optimization" keywords: "active learning, random forest, optimizer, campaign, multi-round, parameter tuning, feature importance, acquisition function, scikit-learn" version: "1.0" last-updated: "2026-05-20"

BY Campaign Optimizer (Active Learning)

Multi-round design campaigns generate scored designs at every iteration. This skill turns that scoring history into actionable parameter changes for the next round — training a lightweight Random Forest on the designs you already have, ranking which features actually discriminate good from bad, and proposing thresholds and design counts that target the most promising regions of feature space.

The optimizer is the iteration loop: it runs after the diagnosis step (by-failure-diagnosis) has identified which features matter, and decides what parameters to push or relax for the next round. Diagnosis answers "what went wrong?"; this skill answers "what should we try next?".

When to Use This Skill

✅ Use this skill when:

• A design round has completed and scores are written to *_scores.json files
• The campaign has ≥10 scored designs total across all rounds
• You are deciding how to configure the next round of a multi-round campaign
• by-failure-diagnosis has identified discriminating features and you need

concrete threshold values

• You want a feature-importance ranking to decide what to optimize for
• The user asks "what should I change for the next round?" or "tune my campaign"

❌ Do NOT use this skill when:

• The campaign has fewer than 10 scored designs → use rule-based defaults from

by-campaign-manager instead

• This is the first round (no prior scores exist) → use by-research and

by-design-workflow to set initial parameters

• Designs are failing for non-statistical reasons (e.g., compute errors, bad

target structure) → run by-failure-diagnosis first to confirm the signal is real

• The campaign is a single-shot screen with no planned iterations
• You only need a "why did designs fail?" report → use by-failure-diagnosis

(the diagnostic counterpart to this optimizer)

Quick Start

from proteus_cli.campaign.active_learning import (
    has_enough_data,
    suggest_from_campaign,
)
campaign_dir = "campaigns/tnfa/campaign_20260520_001"
if has_enough_data(campaign_dir):
    result = suggest_from_campaign(campaign_dir)
    print(f"Source: {result.source}")                  # "active_learning"
    print(f"Confidence: {result.confidence}")          # "high" if >30 designs
    print(f"Top feature: {result.feature_importances[0]}")
    print(f"Recommendations: {result.recommended_parameters}")

Or via the CLI scripts shipped with this skill:

# Step 1: train RF, write optimizer_output.json
python scripts/optimize_from_csv.py \
    --scores campaign/round_1/scores.csv \
    --output campaign/round_1/optimizer_output.json
 
# Step 2: write next-round YAML config
python scripts/propose_next_round.py \
    --optimizer-output campaign/round_1/optimizer_output.json \
    --previous-config campaign/round_1/config.yaml \
    --output campaign/round_2/config.yaml

Installation

Or install the ML extras bundle:

pip install by-agent[ml]

License Compliance: All packages permit commercial use in AI applications.

Inputs

Required:

• Scored designs: either
• A campaign directory containing *_scores.json files (Python API), or
• A flat CSV with one row per design (CLI scripts)
• Each scored design must contain numeric values for some subset of:

ipsae (or ipsae_min), iptm, plddt, rmsd, liabilities, cdr3_length, net_charge, hydrophobic_fraction

• A status column (PASS / FAIL) is optional but improves recommendations

Optional:

• min_designs (default 10) — the active-learning threshold
• A previous-round YAML config to use as a template for the next round
• A target feature to optimize (defaults to ipsae)

See references/active-learning.md for sample-size guidance and references/random-forest-approach.md for feature-engineering details.

Outputs

Primary results:

• optimizer_output.json — feature importances, recommended thresholds,

exploration regions, confidence level, and a human-readable explanation

• OptimizationResult dataclass (Python API) with the same content

Next-round config:

• config_round_N+1.yaml — design parameters with adjusted thresholds,

updated num_designs, and feature targets carried over from the optimizer

Diagnostic fields in `optimizer_output.json`:

• source — "active_learning" if RF trained, "rule_based" if fallback
• confidence — "low" / "medium" / "high" based on training-set size
• feature_importances — sorted list of (feature, importance) tuples
• recommended_parameters — concrete values for the next round
• exploration_regions — feature-space regions to sample more densely
• warnings — any files skipped or features dropped

Clarification Questions

⚠️ CRITICAL: ASK THIS FIRST. Always confirm the user has at least 10 scored designs before running the optimizer. Below the threshold, the RF will not train and you should route to rule-based defaults instead.

1. Scored data available? (ASK THIS FIRST)

How many scored designs exist in the campaign? Where are the *_scores.json files (or the scores CSV)? If fewer than 10, stop and use rule-based defaults.

1. Target metric to optimize.

ipSAE is the default. Should we optimize for composite score, ipTM, or a custom weighted target? Different targets produce different recommendations.

1. Pass/fail labels.

Does the data include a status column with PASS/FAIL labels, or only continuous scores? With labels, the optimizer can suggest thresholds that match the empirical pass boundary.

1. Has diagnosis been run?

If by-failure-diagnosis flagged a feature as a strong discriminator, prioritize that feature when interpreting RF importances.

1. Compute and design-count budget for next round.

How many designs is the user willing to run? The optimizer can suggest increase_num_designs if the search space is under-sampled.

1. Diversity vs exploitation.

Should the next round exploit the top-quartile region (narrow thresholds) or explore widely (lower thresholds, higher diversity weight)? See references/active-learning.md#acquisition-functions.

1. Round number.

Which round number is being planned? The optimizer keeps a history file so later rounds can compare improvement trajectories.

Standard Workflow

🚨 MANDATORY: USE THE SHIPPED SCRIPTS — DO NOT REIMPLEMENT THE RF INLINE. 🚨

1. Confirm data sufficiency.

``python from proteus_cli.campaign.active_learning import has_enough_data assert has_enough_data(campaign_dir, min_designs=10) ` ✅ **VERIFICATION:** True printed. If False`, stop and use rule-based defaults.

1. (Optional) Run diagnosis first.

If the previous-round pass rate is below 20%, invoke by-failure-diagnosis to identify discriminating features. Use those features as priors when interpreting the optimizer's importance ranking.

1. Train RF and write optimizer output.

``bash python scripts/optimize_from_csv.py \ --scores campaign/round_N/scores.csv \ --target ipsae \ --output campaign/round_N/optimizer_output.json ` ✅ **VERIFICATION:** ✓ Optimizer completed: N designs, top feature: <feat>`

1. Inspect feature importances.

Read optimizer_output.json. The top feature drives the most variance in ipSAE; the recommended thresholds are derived from the top-quartile mean.

1. Propose next-round config.

``bash python scripts/propose_next_round.py \ --optimizer-output campaign/round_N/optimizer_output.json \ --previous-config campaign/round_N/config.yaml \ --output campaign/round_N+1/config.yaml ` ✅ **VERIFICATION:** ✓ Next-round config written: <path>`

1. Review the diff.

Compare the new config to the previous one. Surface every parameter change to the user before launching the next round.

1. Launch next round.

Hand off to by-design-workflow with the new config. The optimizer does not submit jobs.

❌ DON'T:

• ❌ Skip step 1 — running RF on <10 designs returns garbage importances
• ❌ Discard the optimizer's warnings list — it flags skipped files and dropped features
• ❌ Apply recommendations blindly when confidence is "low" — review with the user first

When Scripts Fail

Follow the standard Script Failure Hierarchy:

1. Fix and retry (90%) — Install scikit-learn / pyyaml; re-run.
2. Modify the script (5%) — Adjust --target or feature list if your

campaign uses non-standard metric names.

1. Use as reference (4%) — Read optimize_from_csv.py and adapt the

training loop if you need a different model class.

1. Write from scratch (1%) — Only if the campaign requires a

fundamentally different optimizer (e.g., Bayesian optimization with a Gaussian process).

For active-learning theory, see references/active-learning.md. For RF hyperparameter rationale, see references/random-forest-approach.md.

Decision Points

See references/active-learning.md#acquisition-functions for the full decision tree.

Common Issues

Best Practices

1. 🚨 CRITICAL: Always check has_enough_data before training — RF on <10 points is meaningless.
2. ✅ REQUIRED: Run by-failure-diagnosis first if previous-round pass rate is below 20%.
3. ✅ Treat importance < 0.10 as noise; do not propagate those features to the next-round config.
4. ✅ Use the top-quartile mean (not the maximum) when deriving thresholds — robust to outliers.
5. ✅ Carry a constant 10% safety margin on thresholds (e.g., min_ipsae = top_quartile_mean * 0.9).
6. ✅ Review the diff between rounds — never auto-apply without user sign-off.
7. ✨ Optional: Average feature importances across the last 3 rounds for stability.
8. ❌ Never use the optimizer as a replacement for diagnosis — they answer different questions.
9. ❌ Never train on data from different targets — restrict to one campaign per fit.
10. ❌ Never push min_ipsae above 0.75 without manual verification — the RF will happily recommend impossible thresholds.

Suggested Next Steps

After running the optimizer:

1. `by-design-workflow` — Launch the next round with the proposed YAML config.

This is the normal forward path once the user approves the recommendations.

1. `by-campaign-manager` — Record the optimizer recommendations and round

number in the campaign state file so later sessions can reconstruct the trajectory.

1. `by-failure-diagnosis` — Re-run after the next round completes to check

whether the predicted discriminators held up empirically. Closed-loop improvement requires this pairing.

1. `by-knowledge` — Persist any surprising findings (e.g., cdr3_length

dominating importance for a specific target family) so future campaigns start with stronger priors.

These chain because each skill operates on a different artifact: the optimizer produces parameters, the workflow consumes them, the campaign manager tracks history, and diagnosis closes the loop on whether the recommendations worked.

Related Skills

Upstream (run first):

• by-failure-diagnosis — Identifies which features discriminate PASS/FAIL.

Use its top features as priors when reading optimizer importances.

• by-screening — Produces the *_scores.json files this skill consumes.

Downstream (run after):

• by-design-workflow — Consumes the next-round YAML and launches the round.
• by-campaign-manager — Persists round history and reconstructs trajectories.

Complementary:

• by-knowledge — Long-term memory across campaigns; learns which features

matter for which target families.

• by-hypothesis-debate — When the optimizer is uncertain (low confidence),

use hypothesis-debate to choose between competing parameter strategies before committing GPU compute.

References

Detailed documentation:

• references/active-learning.md — How active

learning applies to protein design, acquisition functions, sample-size minimums, exploration vs exploitation trade-offs.

• references/random-forest-approach.md —

Random Forest hyperparameters, feature engineering, importance interpretation, fallback behaviour for sparse data.

Scripts:

• scripts/optimize_from_csv.py — CLI: reads scored designs CSV, trains the

Random Forest, writes optimizer_output.json with feature importances and recommendations.

• scripts/propose_next_round.py — CLI: reads optimizer output and a previous

config, writes the next-round YAML config with adjusted thresholds and design parameters.

Key references:

• EVOLVEpro (Science, 2024) — few-shot active learning for protein engineering

using protein language model embeddings. This skill uses hand-crafted structural and developability features instead of PLM embeddings.

• Settles, B. (2009). Active Learning Literature Survey. University of

Wisconsin–Madison Computer Sciences Technical Report 1648.

• Breiman, L. (2001). Random Forests. Machine Learning 45, 5–32.

License: All dependencies (scikit-learn, pandas, numpy, PyYAML) permit commercial use.