Phi4 Abliteration (WIP)

This is Phi4 abliterated using a new methodology (surprisingly?). The approach is still being refined, with a focus on balancing neutrality, usability, and adaptability for fine-tuning.

Goal

The objective is to create a model that is neutral:

Not uncensored, but avoids refusing neutral prompts it would ordinarily reject.
Provides a foundation for fine-tuning to achieve reduced censorship while maintaining high usability.

Original Methodology

In the original implementation:

Harmful and harmless prompts were compared on one specific layer of the model.
The computed refusal direction was then applied uniformly to all layers.

Problem:

This resulted in:

A model that became less usable and less intelligent than the original.
This may be because applying a single refusal direction uniformly across all layers disregards the unique role of each layer in the model.

New Approach

In my fork, available here:
👉 https://github.com/Undi95/abliteration/
(based on the original https://github.com/Orion-zhen/abliteration.git)

I introduced a new approach:

Each layer computes its own refusal direction.
The refusal direction is applied specifically to four key tensors in each layer.

Four Key Tensors Used (for Phi):

For each layer, if a refusal direction exists (layer_idx in refusal_dirs), it is applied as follows:

if layer_idx in refusal_dirs:
    refusal_dir = refusal_dirs[layer_idx]
    lm_model.layers[layer_idx].self_attn.o_proj.weight = modify_tensor(
        lm_model.layers[layer_idx].self_attn.o_proj.weight.data,
        refusal_dir,
        scale_factor,
    )
    lm_model.layers[layer_idx].mlp.down_proj.weight = modify_tensor(
        lm_model.layers[layer_idx].mlp.down_proj.weight.data,
        refusal_dir,
        scale_factor,
    )
    lm_model.layers[layer_idx].post_attention_layernorm.weight = modify_tensor(
        lm_model.layers[layer_idx].post_attention_layernorm.weight.data,
        refusal_dir,
        scale_factor,
    )
    lm_model.layers[layer_idx].input_layernorm.weight = modify_tensor(
        lm_model.layers[layer_idx].input_layernorm.weight.data,
        refusal_dir,
        scale_factor,
    )

Why This Change?

By applying refusal directions individually to each layer's tensors:

The model can retain more specificity and functionality.
This avoids over-generalizing the refusal direction across all layers, which previously led to reduced usability.

Trade-offs:

The more we force refusal directions onto the model:

The more neutral it becomes, but at the risk of becoming dumber.
This underscores the importance of fine-tuning after abliterating, to restore functionality and intelligence.
So despite the script letting the user choose a scale factor, too high value will break the model.

Next Steps

The abliterated model serves as a neutral starting point. Fine-tuning is essential to:

Adjust the model to reduce over-censoring.
Maintain a balance between neutrality and usability.

This is a work in progress, Phi 4 is smoll so I can toy with it.

Replicate

Install my fork
Follow tutorial on github

Launch with enough VRAM : python abliterate.py -m /workspace/microsoft_phi-4 -o ./perfect --deccp --flash-attn --device auto --scan-all --resume --scale-factor 1

If you want to use the tensors available here, just put the refusal_tensors/ folder at the root of the script, you will then be able to use: python chat.py -m /workspace/microsoft_phi-4 then select layer range "1;39", and scale factor to 1.0.

Rename the tensors as needed. My code is shit, please understand, idea is better than code. Do better. kek.

Undi95
/

Phi4-abliterated