EXPLAINER

What are LLM Benchmarks?

FARPOINT RESEARCH

LLM benchmarks are standardized frameworks designed to evaluate the performance of large language models (LLMs). These benchmarks include sample datasets, a series of questions or tasks that assess specific skills, performance metrics, and a scoring system to measure results.

Models are evaluated based on their capabilities in areas such as coding, common sense reasoning, and natural language processing tasks like machine translation, question answering, and text summarization.

LLM benchmarks are essential for the development and refinement of models. They track an LLM’s progress through quantitative metrics that highlight its strengths and areas for improvement, guiding the fine-tuning process. This supports researchers and developers in advancing the field. Additionally, benchmarks offer an objective comparison of different models, assisting software developers and organizations in selecting the most suitable models for their needs.

How LLM benchmarks work

LLM benchmarks operate in a clear and straightforward manner. They present a task for an LLM to complete, evaluate the model’s performance using specific metrics, and generate a score based on those metrics. Here’s a detailed look at each step:

Setting Up

LLM benchmarks come with pre-prepared sample data, such as coding challenges, extensive documents, math problems, real-world conversations, and science questions. A variety of tasks, including commonsense reasoning, problem-solving, question answering, summary generation, and translation, are provided to the model at the beginning of testing.

Testing

During benchmarking, models are evaluated in one of three ways:

Few-shot: The LLM is given a small number of examples demonstrating how to perform a task before it is prompted to complete the task. This evaluates the model’s ability to learn with limited data.

Zero-shot: The LLM is prompted to complete a task without any prior examples. This tests the model’s ability to comprehend new concepts and adapt to novel scenarios.

Fine-tuned: The model is trained on a dataset similar to the benchmark tasks, aiming to enhance the LLM’s performance on specific tasks associated with the benchmark.

Scoring

After testing, the benchmark calculates how closely a model’s output matches the expected solution or standard answer, generating a score typically between 0 and 100.

Key metrics for benchmarking LLMs

Different metrics are applied to evaluate the performance of LLMs. Here are some common ones:

Accuracy or Precision calculates the percentage of correct predictions.

Recall, also known as sensitivity rate, quantifies the number of true positives–the actual correct predictions.

F1 Score combines accuracy and recall into one metric, considering both measures to balance any false positives or false negatives. F1 scores range from 0 to 1, with 1 indicating excellent recall and precision.

Exact Match measures the proportion of predictions that exactly match the expected outcome, particularly useful for tasks like translation and question answering.

Perplexity assesses a model's predictive accuracy. Lower perplexity scores indicate better comprehension of a task.

Bilingual Evaluation Understudy (BLEU) evaluates machine translation by calculating the matching n-grams (a sequence of n-adjacent text symbols) between the model's translation and a human reference.

Recall-Oriented Understudy for Gisting Evaluation (ROUGE) measures text summarization with several variants. ROUGE-N is similar to BLEU for summaries, while ROUGE-L computes the longest common subsequence between the model-generated summary and the human reference.

Typically, these quantitative metrics are combined for a more comprehensive and robust assessment.

Human evaluation, on the other hand, involves qualitative metrics such as coherence, relevance, and semantic meaning. While human assessors can provide a nuanced evaluation, this process can be labor-intensive, subjective, and time-consuming. Therefore, a balance of both quantitative and qualitative metrics is essential for a thorough evaluation.

Limitations of LLM benchmarks

While benchmarks are strong indicators of LLM performance, they cannot fully predict how a model will function in real-world scenarios. Here are a few constraints of LLM benchmarks:

Bounded Scoring: Once a model achieves the highest possible score on a benchmark, the benchmark must be updated with more challenging tasks to remain a useful measure.

Broad Dataset: LLM benchmark often use sample data from a wide range of subjects and tasks, which may not be suitable for edge cases, specialized areas, or specific use cases.

Finite Assessments: Benchmarks can only evaluate a model's current capabilities. As LLMs evolve and develop new abilities, new benchmarks will be necessary.

Overfitting: Training an LLM on the same dataset used for benchmarking can lead to overfitting, where the model performs well on test data but poorly on real-world data. This results in a score that does not accurately reflect the model's true capabilities.

Aggregate Scoring: Some benchmarks, like the Massive Multitask Language Understanding (MMLU), report only aggregate scores without breaking down performance by subject. This lack of granularity can obscure specific areas where a model excels or needs improvement, making it harder to identify strengths and weaknesses.

What are LLM leaderboards?

LLM leaderboards rank large language models based on their performance across various benchmarks. These leaderboards offer a valuable way to track and compare the myriad of LLMs available, making them particularly useful for decision-making regarding which models to use.

Each benchmark typically has its own dedicated leaderboard, but independent LLM leaderboards also exist. For example, Hugging Face hosts a collection of leaderboards, including an open LLM leaderboard that ranks multiple open-source models based on the ARC, HellaSwag, MMLU, GSM8K, TruthfulQA and Winogrande benchmarks.

Common LLM benchmarks

Researchers classify LLM benchmarks based on two main aspects:

  1. Assessment Criteria: LLM evaluation metrics can either be based on ground truth or human preferences. Ground truth refers to information assumed to be accurate and factual, while human preferences reflect choices and judgments based on real-world usage.
  2. Source of Questions: Prompts used in benchmarks can originate from either static or live sources. Static prompts are predefined questions, while live prompts are generated in interactive environments.

Benchmarks can fall into one or more of these categories. Here's an overview of how some popular benchmarks operate:

AI2 Reasoning Challenge (ARC):

The ARC benchmark evaluates an LLM’s question-answering and reasoning abilities using over 7,000 grade-school natural science questions. These questions are divided into an easy set and a challenge set. Scoring is straightforward, with models earning one point for each correct answer and 1/N points if multiple answers are provided and one is correct.

Learn more about ARC

Chatbot Arena:

Chatbot Arena is an open benchmark platform that pits two anonymous chatbots against each other in random real-world conversations. Users then vote on which chatbot they prefer, after which the models’ identities are revealed. This crowdsourced data is used to estimate scores and create approximate rankings for various LLMs, utilizing sampling algorithms to pair models.

Perform a live Chatbot Arena eval

Grade School Math 8K (GSM8K):

GSM8K tests an LLM’s mathematical reasoning skills with a corpus of 8,500 grade-school math word problems. Solutions are provided in natural language rather than mathematical expressions, and AI verifiers are trained to evaluate these solutions.

Learn more about GSM8K

HellaSwag:

HellaSwag, an acronym for “Harder Endings, Longer contexts and Low-shot Activities for Situations With Adversarial Generations,” focuses on commonsense reasoning and natural language inference. Models complete sentences by choosing from several possible endings, including wrong answers generated through adversarial filtering. Accuracy is evaluated for both few-shot and zero-shot categories.

Learn more about HellaSwag

HumanEval:

HumanEval assesses an LLM’s code generation performance by evaluating functional correctness. Models solve programming problems and are evaluated based on passing the corresponding unit tests. The evaluation metric, pass@k, measures the probability that at least one of the k-generated code solutions passes the unit tests.

Learn more about HumanEval

Massive Multitask Language Understanding (MMLU):

MMLU assesses an LLM’s breadth of knowledge, natural language understanding, and problem-solving ability across more than 15,000 multiple-choice general knowledge questions covering 57 subjects. Evaluation is done in few-shot and zero-shot settings, with the final score averaging the model’s accuracy across subjects.

Learn more about MMLU

Mostly Basic Programming Problems (MBPP):

MBPP, or Mostly Basic Python Problems, is a code generation benchmark with over 900 coding tasks. It evaluates functional correctness based on test cases, using metrics like the percentage of problems solved by any sample from the model and the percentage of samples solving their respective tasks.

Learn more about MBPP

MT-Bench:

Created by the researchers behind Chatbot Arena, MT-Bench tests an LLM’s dialogue and instruction-following abilities with open-ended multi-turn questions across eight areas: coding, extraction, knowledge I (STEM), knowledge II (humanities and social sciences), math, reasoning, roleplay, and writing. GPT-4 is used to evaluate responses.

Learn more about MT-Bench

SWE-bench:

Similar to HumanEval, SWE-bench evaluates an LLM’s code generation skills, focusing on issue resolution. Models fix bugs or address feature requests in specific code bases, with performance measured by the percentage of resolved task instances.

Learn more about SWE-bench

TruthfulQA:

Addressing the tendency of LLMs to hallucinate, TruthfulQA measures an LLM’s ability to generate truthful answers. Its dataset includes over 800 questions across 38 subjects, combining human evaluation with the GPT-3 LLM fine-tuned on BLEU and ROUGE metrics to predict informativeness and truthfulness.

Learn more about TruthfulQA

Winogrande:

Winogrande evaluates commonsense reasoning abilities and builds on the original Winograd Schema Challenge. It features a large dataset of 44,000 crowdsourced problems, using adversarial filtering to ensure complexity. Scoring is based on accuracy.

Learn more about Winogrande

In the rapidly advancing field of AI, LLM benchmarks serve as vital tools for evaluating and refining large language models. They provide essential insights into a model’s strengths and areas for improvement, guiding researchers and developers toward creating more robust and capable AI systems. By offering standardized metrics and frameworks, benchmarks help ensure that LLMs meet high performance and reliability standards, fostering trust and adoption in various applications.

However, it’s important to recognize the limitations of current benchmarks. Continuous innovation in benchmarking practices is necessary to keep pace with the evolving capabilities of LLMs. This includes updating benchmarks with more challenging tasks, addressing overfitting issues, and providing more granular performance metrics.

As the AI landscape continues to grow and diversify, the role of benchmarks will remain crucial. They not only drive the advancement of AI technologies but also support informed decision-making for organizations seeking to integrate AI solutions. By understanding and leveraging the insights provided by LLM benchmarks, we can build more effective, reliable, and ethical AI systems that meet the complex demands of real-world applications.

At Farpoint, we are committed to advancing the field of AI through rigorous evaluation and benchmarking practices. We invite researchers, developers, and organizations to join us in this mission. Explore our resources, participate in our initiatives, and contribute to the ongoing dialogue about best practices in AI benchmarking.