# Fine-tuning LLM for RAG
**URL:**
**Author:**  [@Chahnwoo](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2FChahnwoo)%5C
**Post date:** [June 10, 2024, 12:33am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ffine-tuning-llm-for-rag%2F91225%2F1 "2024-06-10T00:33:11Z")
I am currently fine-tuning a LLM with a custom QA dataset, and was wondering whether there would be a significant difference whether I ran QLoRA fine-tuning with a model initialized with **AutoModelForCausalLM** and a model initialized with **AutoModelForQuestionAnswering**. If there does exist a significant difference, which of the two is preferrable?
For additional context, the dataset I will be fine-tuning with consists of three columns: _question_, _context_, and _answer_. The three columns are then formatted with a prompt along the lines of
```auto
### Instruction
Use the context below to generate an answer to the provided question. If the context does not contain sufficient information, state that an answer could not be found.
### Context
{context}
### Question
{question}
### Response
{response}
```
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**Author:**  [@nielsr](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fnielsr)%5C
**Post date:** [June 10, 2024, 7:14am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ffine-tuning-llm-for-rag%2F91225%2F2 "2024-06-10T07:14:00Z")
Hi,
The difference is generative vs. extractive question answering.
The **AutoModelForQuestionAnswering** class is meant for extractive question answering, i.e. the model is a classifier and needs to determine which text token of the context is at the start of the answer and which part of the context is at the end.
The **AutoModelForCausalLM** classs is meant for generative question answering, i.e. the model is a generative model (like ChatGPT) and can generate any text given the context + question. This means that the model can give answers that go beyond the literate text of the context.
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**Author:**  [@system](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fsystem)%5C
**Post date:** [June 18, 2024, 12:08am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ffine-tuning-llm-for-rag%2F91225%2F3 "2024-06-18T00:08:03Z")
Closed on June 18, 2024, 12:08am UTC
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