Skip to content

Structural control

aisteer360.algorithms.structural_control.base

Structural control base classes.

This module provides the abstract base class for methods that create persistent changes to the model, either through weight updates or architectural changes.

Two base classes are provided:

  • StructuralControl: Base class for all structural control methods.
  • NoStructuralControl: Identity (null) control; used when no structural control is defined in steering pipeline.

Structural controls implement steering through model weight or architecture modifications, transforming base parameters θ to θ', resulting in generations following y ~ p_θ'(x).

Examples of structural controls:

  • Fine-tuning (full or parameter-efficient like LoRA)
  • Model merging (e.g., via MergeKit)
  • Direct Preference Optimization (DPO)
  • Adapter layers and modules
  • Weight interpolation and averaging

See Also:

  • aisteer360.algorithms.structural_control: Implementations of structural control methods
  • aisteer360.core.steering_pipeline: Integration with steering pipeline

NoStructuralControl

Bases: StructuralControl

Identity structural control.

Used as the default when no structural control is needed. Passes the model through unchanged.

Source code in aisteer360/algorithms/structural_control/base.py 
72
73
74
75
76
77
78
79
80
81
class NoStructuralControl(StructuralControl):
    """Identity structural control.

    Used as the default when no structural control is needed. Passes the model through unchanged.
    """
    enabled: bool = False

    def steer(self, model: PreTrainedModel, **__) -> PreTrainedModel:
        """Null steer operation; returns model."""
        return model

args = self.Args.validate(*args, **kwargs) instance-attribute

enabled = False class-attribute instance-attribute

steer(model, **__)

Null steer operation; returns model.

Source code in aisteer360/algorithms/structural_control/base.py 
79
80
81
def steer(self, model: PreTrainedModel, **__) -> PreTrainedModel:
    """Null steer operation; returns model."""
    return model

StructuralControl

Bases: ABC

Abstract base class for structural control steering methods.

Modifies model parameters or architecture persistently, returning a new model instance with transformed weights.

Methods:

Name Description
steer

Training logic (required)
Source code in aisteer360/algorithms/structural_control/base.py 
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
class StructuralControl(ABC):
    """Abstract base class for structural control steering methods.

    Modifies model parameters or architecture persistently, returning a new model instance with transformed weights.

    Methods:
        steer(model, tokenizer, **kwargs) -> PreTrainedModel: Training logic (required)
    """

    Args: Type[BaseArgs] | None = None

    enabled: bool = True

    def __init__(self, *args, **kwargs) -> None:
        if self.Args is None:  # null control
            if args or kwargs:
                raise TypeError(f"{type(self).__name__} accepts no constructor arguments.")
            return

        self.args: BaseArgs = self.Args.validate(*args, **kwargs)

        # move fields to attributes
        for field in fields(self.args):
            setattr(self, field.name, getattr(self.args, field.name))

    @abstractmethod
    def steer(
            self,
            model: PreTrainedModel,
            tokenizer: PreTrainedTokenizer = None,
            **kwargs
    ) -> PreTrainedModel:
        """Required steering/preparation."""
        pass

args = self.Args.validate(*args, **kwargs) instance-attribute

enabled = True class-attribute instance-attribute

steer(model, tokenizer=None, **kwargs) abstractmethod

Required steering/preparation.

Source code in aisteer360/algorithms/structural_control/base.py 
61
62
63
64
65
66
67
68
69
@abstractmethod
def steer(
        self,
        model: PreTrainedModel,
        tokenizer: PreTrainedTokenizer = None,
        **kwargs
) -> PreTrainedModel:
    """Required steering/preparation."""
    pass