How to go about explaining or interpreting text for chat completion models?

[karrtikiyer-tw]

Hi community,
Any thoughts on how we can get some of the lime tool explainers to work on the Open AI Chat Completion models?
Any advise or help appreciated.
Thanks,
Karrtik

[Siddharth-Latthe-07]

@karrtikiyer-tw Interesting topic,
here are some of the introductory steps that will help you to get an idea regarding the above,

1. install the required libraries (lime)
2. define a wrapper function:-
   As LIME requires a prediction function that returns a probability distribution over classes and Since Chat Completion models provide text, you need to define a function that translates the text output into a format suitable for LIME.

import openai

def openai_completion(prompt, model="gpt-4", max_tokens=50):
    response = openai.Completion.create(
        engine=model,
        prompt=prompt,
        max_tokens=max_tokens,
        n=1,
        stop=None,
        temperature=0.7
    )
    return response.choices[0].text.strip()

3. create function for lime explainer:-
   For text models, it involves altering the input text slightly and observing the resulting completions.

from lime.lime_text import LimeTextExplainer
import numpy as np

class OpenAIWrapper:
    def __init__(self, model="gpt-4"):
        self.model = model
    
    def predict_proba(self, texts):
        # Define the class labels
        classes = ['positive', 'negative']
        
        # Simulate probabilities (for demonstration)
        # In practice, you'd replace this with a real probability scoring
        probas = []
        for text in texts:
            completion = openai_completion(text, model=self.model)
            # Dummy scoring: length-based probability (you'll need a real classifier)
            probas.append([len(completion) % 2, (len(completion) + 1) % 2])
        return np.array(probas)

# Initialize LIME explainer and the OpenAI model wrapper
explainer = LimeTextExplainer(class_names=['positive', 'negative'])
model_wrapper = OpenAIWrapper(model="gpt-4")

# Example text input
text = "The weather today is"

# Generate explanation
exp = explainer.explain_instance(text, model_wrapper.predict_proba, num_features=10)

# Print the explanation
print(exp.as_list())

and finally, interpreting the results, through the explain_instance function
Hope, this would give you a brief idea, open for your thoughts on this
Thanks