| Maxime Lbonne August 7, 2024 Orca is a 13B parameter LLM with ChatGPT level of performance thanks to a huge dataset of 5M samples with step-by-step explanations. |
| 📝 Paper: https://arxiv.org/abs/2306.02707 The model will probably never be released by Microsoft, but open-source projects try to replicate it (OpenOrca, Dolphin). |
| The authors note that while Vicuna-13B display excellent performance when evaluated with GPT-4, it performs quite poorly on reasoning benchmarks like SAT, LSAT, GRE, GMAT. |
| Self-Instruct involves using an initial set of prompts to ask an LLM to create new instructions. |
| Low-quality or overly similar responses are removed, and the remaining instructions are recycled back into the task pool for further iterations. |
| However, the queries generated via Self-Instruct can lack diversity and complexity. |
| Problem with natural conversations: LLMs like Vicuna capture the style but not the reasoning process. |
| This motivates the creation of a dataset with step-by-step explanations. |
| Using GPT-4 for auto-evaluation has several drawbacks, such as limited test set sizes (for example, 80 instructions in Vicuna and 218 in WizardLM) and the inherent biases of GPT-4. |
| It tends to favor models that are instruction-tuned with its own responses, resulting in a preference for longer texts over shorter ones. |
| It also exhibits a bias in the order of candidate responses and overestimates the abilities of smaller models. |
| Contributions: The authors focus a lot on system instructions and how they can be used to guide the model into adopting the right tone, task, and format. |
| I believe the same effect can be achieved with user instructions (maybe system instructions are slightly more accurate?). |
| System instructions are sampled from a diverse instruction set including chain-of-thought reasoning steps, explain like I’m five, being helpful and informative, etc. |
| Each training sample is a triplet with system message, user message, and response. |
| The authors use the FLAN-v2 dataset as raw data. |
| The FLAN-v2 Collection consists of five sub-collections: CoT, NiV2, T0 (training only), Flan 2021, Dialogue: The resulting 5M samples are then used as inputs to generate high-quality responses with ChatGPT (5M) and GPT-4 (1M). |
| These models are prompted with the inputs + 16 handcrafted system messages to ensure different kinds of responses: This is motivated by curriculum learning (learning with a smaller model first, then with a big model) and technical reasons (cost, time). |
| They use the LLaMA BPE tokenizer with padding (vocabulary size = 32,001). |
| Multiple input examples are packed into a single sequence to maximize the used context length (2,048 tokens). |
| They use padding tokens to get a uniform size. |
| It was trained for 160h on 20xA100 GPUs (4 epochs) on the 5M ChatGPT-generated samples + 40h on the 1M GPT-4-generated samples. |
| Open-ended generation: Orca is significantly better than Vicuna. |
| AGIEval: Orca doesn’t perform as well as ChatGPT. |
| BigBench-Hard: Orca is on par with ChatGPT. |
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