- What Is Different About This Model?
- Methodology
- 1. Source Dataset Construction
- 2. External Style Representation
- 3. Distributional Rather Than Prompt-Local Geometry
- 4. Cross-Model Style Signal
- 5. Target-Model Hidden-State Extraction
- 6. Hidden-State Style Surrogate
- 7. Cached Reference Policy
- 8. Reference-Relative Style Shift
- 9. Finite Target Margin
- 10. Orthogonal Trust Constraint
- 11. Final Training Objective
- 12. Relationship to IPO
- 13. How the LoRA Weights Are Updated
- Summary
What Is Different About This Model?
No human-continuation imitation: The model was not trained with ordinary SFT/NLL against paired human stories. Human writing is used to define a broader stylistic distribution rather than as an exact continuation target.
Style is learned as a distributional signal: Human, GPT-3.5, Claude Opus, and base-model outputs were analyzed in StyleDistance space to identify stylistic structure that generalizes across different machine-writing populations.
The training signal operates on predictive hidden states: A linear critic maps the model's final hidden representation immediately before the LM head to a continuous human-associated style score.
Training is reference-relative: For each base-policy (
Ο0) response, the adapted model's hidden trajectory is compared against the cached hidden trajectory of the unmodified model on the exact same text.The objective uses a finite target margin: Rather than maximizing the style critic indefinitely, each response is assigned a bounded desired shift based on its original score. Lower-scoring outputs receive more correction, while already-high-scoring outputs receive reduced or zero pressure.
Unrelated representation movement is penalized: Hidden-state displacement orthogonal to the validated style direction is explicitly discouraged, favoring comparatively small targeted changes over broad representational drift.
No token-level likelihood loss is used: The LoRA is optimized directly from the hidden-state style objective; no chosen/rejected log-probability loss and no next-token NLL term are included.
Conceptually IPO-like, but in representation space: IPO regresses toward a finite reference-relative preference margin in log-probability space. This method instead regresses toward a finite reference-relative style margin in predictive hidden-state space.
Methodology
This model was trained using a reference-relative hidden-state style objective designed to move the model's creative-writing distribution toward stylistic regions associated with human writing without directly maximizing the likelihood of specific human-written continuations.
The method is loosely analogous to IPO in that it optimizes toward a finite target margin rather than an unbounded reward, but the margin is measured in a learned hidden-state style direction rather than in chosen/rejected log-probability ratios.
Pipeline Overview
Human + machine creative-writing responses
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Prompt-grouped dataset
1,443 unique prompt groups
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βββββββββ Human responses
βββββββββ GPT-3.5 responses
βββββββββ Claude Opus responses
βββββββββ Base-policy (Ο0) responses
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5,733 complete texts
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StyleDistance embeddings
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Learn continuous humanβmachine
stylistic scalar field
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Teacher-force the same texts through
the target 70B base model
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Pool final predictive hidden states
over response positions
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Fit linear hidden-state surrogate
to the external style scalar
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Source-center GPT / Opus / Ο0 targets
to isolate shared within-machine variation
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Frozen 8,192-D critic
s(h) = wα΅h + b
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Cache Ο0 reference hidden trajectories
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LoRA policy training
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Compare adapted hidden trajectory
to its frozen Ο0 reference trajectory
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Move a bounded distance along the
validated human-associated style direction
while penalizing orthogonal movement
1. Source Dataset Construction
The starting dataset consists of human-written creative-writing responses paired with machine-generated responses to the same prompts.
Repeated human responses that had separately been paired with GPT-3.5 and Claude Opus generations were collapsed into shared prompt groups. Each group therefore represents one underlying writing task and its available alternative continuations.
The resulting corpus contains:
- 1,443 unique prompt groups
- 1,443 human responses
- 1,421 GPT-3.5 responses
- 1,426 Claude Opus responses
- 1,443 base-policy (
Ο0) responses - 5,733 total texts
One additional response was generated from the unmodified target model for every prompt. These Ο0 generations provide a complete snapshot of the model distribution immediately before the intervention.
Responses belonging to the same prompt share a common group_id, allowing all validation procedures to remain prompt-disjoint.
2. External Style Representation
Each complete response was embedded using StyleDistance, providing a representation intended to emphasize stylistic rather than primarily semantic differences.
Long responses were processed in chunks and pooled into a single full-response representation.
Human and machine populations were then used to construct a continuous scalar field in StyleDistance space. Higher values correspond to regions more strongly associated with the human-writing population.
Importantly, the paired human continuation is not treated as the correct target response. Human examples instead define a population-level stylistic distribution.
This distinction is central to the method:
Not:
machine response β imitate paired human response
Instead:
machine distribution β move toward stylistic structure
associated with the human distribution
3. Distributional Rather Than Prompt-Local Geometry
Several possible geometric formulations were tested before selecting the final target.
Simple human-centroid attraction and machine-centroid repulsion were rejected because the populations occupy structured, partially overlapping regions rather than lying along one global axis.
Prompt-local correction vectors such as:
human β GPT
human β Opus
were also tested.
Their apparent alignment did not survive anchor-preserving permutation controls, indicating that the paired human continuation does not define a reliable unique correction direction for each prompt.
The final methodology therefore treats the signal as a population-level style field, not as a collection of machine-to-human rewrite vectors.
4. Cross-Model Style Signal
The StyleDistance human/machine boundary transfers strongly across machine families.
A boundary learned from GPT-3.5 and Opus generalizes to the previously unseen Ο0 population, supporting the existence of a shared machine-writing component rather than only model-specific fingerprints.
This motivated retaining multiple machine populations while keeping their source identities distinct.
5. Target-Model Hidden-State Extraction
All 5,733 texts were then teacher-forced through the exact target base model:
Jolly-Q/Llama-3.3-70B-Inst-Ablit-Flammades-SLERP
The exact model revision used for hidden-state extraction was recorded and later pinned during LoRA training.
For each response, the final normalized hidden states immediately before the language-model head were extracted.
If response tokens occupy positions:
[s, e)
the corresponding predictive hidden states are:
[s-1, e-1)
because those are the causal states whose logits predict the response tokens.
These states were averaged to obtain one 8,192-dimensional predictive representation per response:
No arbitrary context truncation was required. The longest complete templated sequence contained only 3,688 tokens.
6. Hidden-State Style Surrogate
A linear surrogate was fitted to predict the externally derived StyleDistance scalar from the model's mean final predictive hidden state.
The strongest formulation used the three machine populations:
- GPT-3.5
- Claude Opus
Ο0
Before regression, the mean target score of each machine source was subtracted.
This source-centering removes easy between-model offsets and forces the critic to learn stylistic variation shared within machine populations.
The final critic therefore has the form:
where higher values indicate movement toward the human-associated direction learned from the dataset.
The critic was selected using group-disjoint cross-validation and achieves approximately:
- Ο0 Spearman Ο: 0.619
- GPT-3.5 Spearman Ο: 0.587
- Opus Spearman Ο: 0.643
The final critic is an 8,192-dimensional linear direction rather than a large neural reward model.
7. Cached Reference Policy
For every Ο0 training example, the original base model's predictive mean hidden state was retained:
During LoRA training, the same text is teacher-forced through the adapted model to obtain:
This makes the training objective explicitly reference-relative while avoiding the need to keep a second frozen 70B reference model in memory.
The zero-initialized LoRA was verified against cached reference states before training. Initial critic-score discrepancies were below approximately (4\times10^{-5}), confirming that the live model and cached reference represented effectively the same starting policy.
8. Reference-Relative Style Shift
Training measures how far the adapted model has moved along the frozen critic direction relative to the base policy.
The hidden-state displacement is:
and the corresponding critic-score movement is:
The equivalent calculation is performed in feature-standardized hidden space.
The method therefore does not ask whether the model currently has a high absolute human-style score. It asks:
How far has this response's predictive trajectory moved from the original model in the validated human-associated direction?
9. Finite Target Margin
The critic is not maximized without bound.
Instead, every Ο0 example receives a finite desired improvement:
where:
- (\Delta_{\max}=0.09364), approximately 0.5 standard deviations of the original Ο0 critic-score distribution
- (s_{\mathrm{cap}}=0.222817), approximately the 90th percentile of the original Ο0 distribution
This causes ordinary and low-scoring base responses to receive the full correction pressure while already-high-scoring responses receive progressively less or no pressure.
Conceptually:
low-scoring Ο0 response
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βββ full bounded style shift
middle Ο0 response
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βββ full bounded style shift
high-scoring Ο0 response
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βββ smaller shift
already above score cap
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βββ no positive style pressure
10. Orthogonal Trust Constraint
A scalar critic alone could theoretically be satisfied while the model moves substantially in unrelated hidden-state directions.
To discourage this, standardized hidden displacement is decomposed into:
where (d_\parallel) is parallel to the critic direction and (d_\perp) is orthogonal to it.
The orthogonal component is explicitly penalized:
This encourages the adapter to find a relatively small hidden-state modification that accomplishes the desired stylistic shift rather than arbitrarily restructuring the final representation.
11. Final Training Objective
The style component uses Smooth L1 regression toward the finite target:
with an initial ramp that gradually introduces the full target.
The total objective is:
No ordinary next-token negative log-likelihood term is used.
No paired human response is supplied as a token-level generation target.
No chosen/rejected likelihood comparison is performed.
12. Relationship to IPO
The optimization philosophy is similar to IPO in one important respect: both optimize toward a finite reference-relative margin rather than indefinitely maximizing a reward.
The measured quantities differ:
IPO
chosen + rejected responses
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policy/reference log-probability ratios
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finite preference-margin target
This method
same Ο0 response under base + adapted model
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predictive hidden-state displacement
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frozen style-critic score change
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finite stylistic-margin target
IPO modifies model parameters according to a desired likelihood preference margin.
This method modifies model parameters according to a desired hidden-state stylistic margin.
13. How the LoRA Weights Are Updated
Only LoRA parameters are trainable; the original model weights remain frozen.
For every teacher-forced response:
tokens
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base transformer + trainable LoRA
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final predictive hidden states
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mean response representation
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compare with cached Ο0 representation
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style-margin + orthogonal loss
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backpropagation
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LoRA A/B matrices only
Because the critic is linear:
the final hidden-state gradient has a directly interpretable preferred direction.
Backpropagation through the transformer determines which LoRA parameter changes produce that movement in the final predictive representation.
The language-model head is not required during loss calculation; the optimization acts directly on the final transformer representation immediately upstream of the output logits.
Summary
The training procedure can be summarized as:
Human + heterogeneous machine writing
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External style-space analysis
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Continuous human-associated style field
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Target-model predictive hidden states
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Cross-model linear hidden-state critic
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Frozen Ο0 hidden-state references
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Teacher-forced LoRA model
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Measure reference-relative style movement
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Regress toward a bounded positive margin
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Penalize unrelated hidden-state movement
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Update LoRA weights only
The intended effect is therefore not to imitate individual human examples, but to apply a controlled distributional intervention to the model's predictive representations in a direction empirically associated with broader human-writing style.