[Bug] Not getting expected labelled few shot examples using DSPy `LabelledFewShot`

[yash-raj-verma]

What happened?

We have a dataset with 1000 examples, each example consists of three numbers, two numbers and their sum as the third number. We need to find the best (top) 5 examples from the dataset without bootstrapping (since we have enough labelled examples).

• Why is our forward() method not getting called?
• compiled_rag does not contain any demo examples after the compile() call. Why is it so?

We are attaching a snippet of the code we have so far.

# LearnNumbers.py
import dspy
from dspy.teleprompt import LabeledFewShot

class Prediction(dspy.Signature):
    """Given two numbers give the addition of the two numbers"""
    numbers = dspy.InputField(desc='Two numbers to be added')
    sum = dspy.OutputField(desc='Addition of numbers')


#Assume defined trainset
class LearnSumNumbers(dspy.Module):
    def __init__(self):
        super().__init__()
        self.generate_answer = dspy.Predict(Prediction)

    #flow for answering questions using predictor and retrieval modules
    def forward(self, question):
        prediction = self.generate_answer(question=question)
        return dspy.Prediction(answer=prediction.answer)

#Define teleprompter
teleprompter = LabeledFewShot(k=5)

trainset = [
            dspy.Example(numbers='2 3', sum ='5').with_inputs("numbers"), 
            dspy.Example(numbers='6 6', sum ='12').with_inputs("numbers"), 
            dspy.Example(numbers='5 5', sum ='10').with_inputs("numbers"),
            dspy.Example(numbers='55 7', sum ='62').with_inputs("numbers")
....
# 1000 such examples
] 

compiled_rag = teleprompter.compile(student=LearnSumNumbers(), trainset=trainset)

Please guide us in this matter.

Steps to reproduce

We ran the code on the terminal using python. We used python3 (3.11 version) on Ubuntu (Linux) machine.

$ python3 LearnNumbers.py

DSPy version

2.5

[okhat]

Hey @yash-raj-verma ! Thanks for opening this issue and providing code.

I tested a corrected (and shortened) version of your snippet. It works fine. I'm on latest DSPy 2.6.14. Please feel free to upgrade too, but FWIW I don't think that the version is the issue.

class Prediction(dspy.Signature):
    """Given two numbers give the addition of the two numbers"""

    numbers = dspy.InputField(desc='Two numbers to be added')
    sum = dspy.OutputField(desc='Addition of numbers')

generate_answer = dspy.Predict(Prediction)

#Define teleprompter
trainset = [
            dspy.Example(numbers='2 3', sum ='5').with_inputs("numbers"), 
            dspy.Example(numbers='6 6', sum ='12').with_inputs("numbers"), 
            dspy.Example(numbers='5 5', sum ='10').with_inputs("numbers"),
            dspy.Example(numbers='55 7', sum ='62').with_inputs("numbers")
] 

compiled_rag = dspy.LabeledFewShot(k=5).compile(generate_answer, trainset=trainset)
compiled_rag(numbers='2 3')

dspy.inspect_history()

Works fine. In your code, LearnSumNumbers.forward takes in question and passes that to self.generate_answer. But self.generate_answer accepts numbers and returns sum (not answer).

[lahiri-phdworks]

Thanks for your response. We want to pass our own metric calculation logic to the LabelledFewShots call. Is there a way to do it?

[okhat]

LabelledFewShots has no notion of metric or calculation. It's a "dumb" teleprompter that just copies demonstrations.

Maybe you're thinking of something like BootstrapRS instead?

[yash-raj-verma]

Hello @okhat , Thank you for your response. BootStrapRS is BootStrapRandomSearchWithRandomSearch which synthesizes few-shot examples using bootstrapping.
Is there a way to use BootStrapRandomSearchWithRandomSearch with our own metric logic to get the best possible combination of 5 few-shot examples without bootstrapping?

[subhajitroy]

@okhat Thank you so much for your clarifications. It seems to me that we have a use-case that is perhaps not supported by DsPy. We were looking for a random search over labelled examples, i.e. given a dataset of n labelled examples, we are interested in selecting a subset of k labelled examples which maximizes the performance of the prompt. (The problem is that BootStrapFewShotWithRandomSearch does not allow the number of bootstrap examples to be 0).

I just realized that our issue is similar to: #1425

Can you please confirm that this use-case is not supported? In that case, we can try implementing this functionality, say a LabelledFewShotWithRandomSearch.

[okhat]

Yes. (Maybe you can run BootstrapRS with max_bootstrapped_demos=0, not sure whether that works. It might.)

[subhajitroy]

Thanks! We tried BootstrapRS with max_bootstrapped_demos=0 earlier; it does not work.