Steer Language Model Behavior
Choose The Intervention
- Use prompt or harness controls first when they satisfy the product need and the research question is not about internals.
- Use activation steering for reversible, inference-time causal tests or runtime control.
- Use logit interventions for token-level constraints whose scope can be stated explicitly.
- Use weight-space changes for persistent behavior only after a reversible intervention establishes the direction and regression burden.
Workflow
- Invoke
research-model-representationsto define or validate the steering signal. - Freeze target and guardrail evaluation sets before selecting layers or strengths.
- Record layer, hook point, token position, normalization, sign, magnitude, schedule, and generation settings.
- Sweep a bounded strength range including zero and negative controls.
- Compare with prompt-only, random-direction, and norm-matched controls.
- Measure target success, capability regressions, fluency, calibration, diversity, and off-target behavioral changes.
- For persistent changes, preserve the base checkpoint as immutable, write a new artifact, record both checksums and the transformation, and never edit weights in place.
- Re-run the exact packaged or merged artifact if the intervention becomes persistent.
- Report the smallest effective intervention and the operating range where the claim holds.
Interpretation
A successful steering vector demonstrates controllability under tested conditions. It does not by itself establish a unique representation, a complete mechanism, or safe generalization. Stronger target behavior with broad unrelated regressions is not a clean success.
References
Use references/steering-controls.md as the minimum comparison matrix.