Definition. Base, SFT-positive, and SFT-negative starting-policy triple [ftip-009R]
Definition. Base, SFT-positive, and SFT-negative starting-policy triple [ftip-009R]
For one declared model family and target predicate, a starting-policy triple is
\[ \left (\pi ^{\mathrm {base}},\pi ^+,\pi ^-\right ). \]Here \(\pi ^{\mathrm {base}}\) is the unmodified starting policy, \(\pi ^+\) is obtained by a declared supervised update intended to increase target-response frequency, and \(\pi ^-\) is obtained by a declared update intended to decrease it. The superscripts name producing interventions, not mathematical order relations between the resulting policies.
[clay2026demystifying, Section 4.1] instantiates the triple with the source's Base, SFT-positive, and SFT-negative checkpoints. For the movie quote, its SFT mixture places twenty percent weight on the target quote and eighty percent on other quotes from the Cornell Movie-Dialogs corpus; the negative intervention maximizes cross-entropy loss on the target.