Source-linked AI summary

BLOOM: A 176B-Parameter Open-Access Multilingual Language Model

BigScience Workshop, :, Teven Le Scao, Angela Fan, Christopher Akiki, Ellie Pavlick, Suzana Ilić, Daniel Hesslow, Roman Castagné, Alexandra Sasha Luccioni, François Yvon, Matthias Gallé, Jonathan Tow, Alexander M. Rush, Stella Biderman, Albert Webson, Pawan Sasanka Ammanamanchi, Thomas Wang, Benoît Sagot, Niklas Muennighoff, Albert Villanova del Moral, Olatunji Ruwase, Rachel Bawden, Stas Bekman, Angelina McMillan-Major, Iz Beltagy, Huu Nguyen, Lucile Saulnier, Samson Tan, Pedro Ortiz Suarez, Victor Sanh, Hugo Laurençon, Yacine Jernite, Julien Launay, Margaret Mitchell, Colin Raffel, Aaron Gokaslan, Adi Simhi, Aitor Soroa, Alham Fikri Aji, Amit Alfassy, Anna Rogers, Ariel Kreisberg Nitzav, Canwen Xu, Chenghao Mou, Chris Emezue, Christopher Klamm, Colin Leong, Daniel van Strien, David Ifeoluwa Adelani, Dragomir Radev, Eduardo González Ponferrada, Efrat Levkovizh, Ethan Kim, Eyal Bar Natan, Francesco De Toni, Gérard Dupont, Germán Kruszewski, Giada Pistilli, Hady Elsahar, Hamza Benyamina, Hieu Tran, Ian Yu, Idris Abdulmumin, Isaac Johnson, Itziar Gonzalez-Dios, Javier de la Rosa, Jenny Chim, Jesse Dodge, Jian Zhu, Jonathan Chang, Jörg Frohberg, Joseph Tobing, Joydeep Bhattacharjee, Khalid Almubarak, Kimbo Chen, Kyle Lo, Leandro Von Werra, Leon Weber, Long Phan, Loubna Ben allal, Ludovic Tanguy, Manan Dey, Manuel Romero Muñoz, Maraim Masoud, María Grandury, Mario Šaško, Max Huang, Maximin Coavoux, Mayank Singh, Mike Tian-Jian Jiang, Minh Chien Vu, Mohammad A. Jauhar, Mustafa Ghaleb, Nishant Subramani, Nora Kassner, Nurulaqilla Khamis, Olivier Nguyen, Omar Espejel, Ona de Gibert, Paulo Villegas, Peter Henderson, Pierre Colombo, Priscilla Amuok, Quentin Lhoest, Rheza Harliman, Rishi Bommasani, Roberto Luis López, Rui Ribeiro, Salomey Osei, Sampo Pyysalo, Sebastian Nagel, Shamik Bose, Shamsuddeen Hassan Muhammad, Shanya Sharma, Shayne Longpre, Somaieh Nikpoor, Stanislav Silberberg, Suhas Pai, Sydney Zink, Tiago Timponi Torrent, Timo Schick, Tristan Thrush, Valentin Danchev, Vassilina Nikoulina, Veronika Laippala, Violette Lepercq, Vrinda Prabhu, Zaid Alyafeai, Zeerak Talat, Arun Raja, Benjamin Heinzerling, Chenglei Si, Davut Emre Taşar, Elizabeth Salesky, Sabrina J. Mielke, Wilson Y. Lee, Abheesht Sharma, Andrea Santilli, Antoine Chaffin, Arnaud Stiegler, Debajyoti Datta, Eliza Szczechla, Gunjan Chhablani, Han Wang, Harshit Pandey, Hendrik Strobelt, Jason Alan Fries, Jos Rozen, Leo Gao, Lintang Sutawika, M Saiful Bari, Maged S. Al-shaibani, Matteo Manica, Nihal Nayak, Ryan Teehan, Samuel Albanie, Sheng Shen, Srulik Ben-David, Stephen H. Bach, Taewoon Kim, Tali Bers, Thibault Fevry, Trishala Neeraj, Urmish Thakker, Vikas Raunak, Xiangru Tang, Zheng-Xin Yong, Zhiqing Sun, Shaked Brody, Yallow Uri, Hadar Tojarieh, Adam Roberts, Hyung Won Chung, Jaesung Tae, Jason Phang, Ofir Press, Conglong Li, Deepak Narayanan, Hatim Bourfoune, Jared Casper, Jeff Rasley, Max Ryabinin, Mayank Mishra, Minjia Zhang, Mohammad Shoeybi, Myriam Peyrounette, Nicolas Patry, Nouamane Tazi, Omar Sanseviero, Patrick von Platen, Pierre Cornette, Pierre François Lavallée, Rémi Lacroix, Samyam Rajbhandari, Sanchit Gandhi, Shaden Smith, Stéphane Requena, Suraj Patil, Tim Dettmers, Ahmed Baruwa, Amanpreet Singh, Anastasia Cheveleva, Anne-Laure Ligozat, Arjun Subramonian, Aurélie Névéol, Charles Lovering, Dan Garrette, Deepak Tunuguntla, Ehud Reiter, Ekaterina Taktasheva, Ekaterina Voloshina, Eli Bogdanov, Genta Indra Winata, Hailey Schoelkopf, Jan-Christoph Kalo, Jekaterina Novikova, Jessica Zosa Forde, Jordan Clive, Jungo Kasai, Ken Kawamura, Liam Hazan, Marine Carpuat, Miruna Clinciu, Najoung Kim, Newton Cheng, Oleg Serikov, Omer Antverg, Oskar van der Wal, Rui Zhang, Ruochen Zhang, Sebastian Gehrmann, Shachar Mirkin, Shani Pais, Tatiana Shavrina, Thomas Scialom, Tian Yun, Tomasz Limisiewicz, Verena Rieser, Vitaly Protasov, Vladislav Mikhailov, Yada Pruksachatkun, Yonatan Belinkov, Zachary Bamberger, Zdeněk Kasner, Alice Rueda, Amanda Pestana, Amir Feizpour, Ammar Khan, Amy Faranak, Ana Santos, Anthony Hevia, Antigona Unldreaj, Arash Aghagol, Arezoo Abdollahi, Aycha Tammour, Azadeh HajiHosseini, Bahareh Behroozi, Benjamin Ajibade, Bharat Saxena, Carlos Muñoz Ferrandis, Daniel McDuff, Danish Contractor, David Lansky, Davis David, Douwe Kiela, Duong A. Nguyen, Edward Tan, Emi Baylor, Ezinwanne Ozoani, Fatima Mirza, Frankline Ononiwu, Habib Rezanejad, Hessie Jones, Indrani Bhattacharya, Irene Solaiman, Irina Sedenko, Isar Nejadgholi, Jesse Passmore, Josh Seltzer, Julio Bonis Sanz, Livia Dutra, Mairon Samagaio, Maraim Elbadri, Margot Mieskes, Marissa Gerchick, Martha Akinlolu, Michael McKenna, Mike Qiu, Muhammed Ghauri, Mykola Burynok, Nafis Abrar, Nazneen Rajani, Nour Elkott, Nour Fahmy, Olanrewaju Samuel, Ran An, Rasmus Kromann, Ryan Hao, Samira Alizadeh, Sarmad Shubber, Silas Wang, Sourav Roy, Sylvain Viguier, Thanh Le, Tobi Oyebade, Trieu Le, Yoyo Yang, Zach Nguyen, Abhinav Ramesh Kashyap, Alfredo Palasciano, Alison Callahan, Anima Shukla, Antonio Miranda-Escalada, Ayush Singh, Benjamin Beilharz, Bo Wang, Caio Brito, Chenxi Zhou, Chirag Jain, Chuxin Xu, Clémentine Fourrier, Daniel León Periñán, Daniel Molano, Dian Yu, Enrique Manjavacas, Fabio Barth, Florian Fuhrimann, Gabriel Altay, Giyaseddin Bayrak, Gully Burns, Helena U. Vrabec, Imane Bello, Ishani Dash, Jihyun Kang, John Giorgi, Jonas Golde, Jose David Posada, Karthik Rangasai Sivaraman, Lokesh Bulchandani, Lu Liu, Luisa Shinzato, Madeleine Hahn de Bykhovetz, Maiko Takeuchi, Marc Pàmies, Maria A Castillo, Marianna Nezhurina, Mario Sänger, Matthias Samwald, Michael Cullan, Michael Weinberg, Michiel De Wolf, Mina Mihaljcic, Minna Liu, Moritz Freidank, Myungsun Kang, Natasha Seelam, Nathan Dahlberg, Nicholas Michio Broad, Nikolaus Muellner, Pascale Fung, Patrick Haller, Ramya Chandrasekhar, Renata Eisenberg, Robert Martin, Rodrigo Canalli, Rosaline Su, Ruisi Su, Samuel Cahyawijaya, Samuele Garda, Shlok S Deshmukh, Shubhanshu Mishra, Sid Kiblawi, Simon Ott, Sinee Sang-aroonsiri, Srishti Kumar, Stefan Schweter, Sushil Bharati, Tanmay Laud, Théo Gigant, Tomoya Kainuma, Wojciech Kusa, Yanis Labrak, Yash Shailesh Bajaj, Yash Venkatraman, Yifan Xu, Yingxin Xu, Yu Xu, Zhe Tan, Zhongli Xie, Zifan Ye, Mathilde Bras, Younes Belkada, Thomas Wolf

arXiv:2211.05100v4cs.CL

TL;DR

Most large language models are developed by resource-rich organizations and often kept from the public, limiting broad participation in their development. BLOOM is a 176B-parameter multilingual model developed by hundreds of researchers; it achieves competitive benchmark performance, with stronger results after multitask prompted finetuning.

  • Problem

    Most LLMs were developed by well-resourced organizations and not publicly released, leaving much of the research community excluded from their development.

    Source: §1 · p. 4
  • Method

    BLOOM is a 176-billion-parameter model developed by hundreds of researchers and trained on 46 natural and 13 programming languages.

    Source: §1 · p. 4
  • Results

    BLOOM achieves competitive performance across evaluations, improving after multitask finetuning.

    Source: §5 · p. 43
  • Takeaways & Limitations

    BLOOM’s public release adds a multilingual language model to a field where most models were not publicly released.

    Source: §1 · p. 4

    For summarization, ROUGE-2 scores can understate the quality of generated summaries.

    Source: §4.4 · p. 32

Abstract

from arXiv · show

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License.

1. Introduction

Pretrained language models have improved NLP performance and demonstrated useful task performance without additional training, but the costs and limited release of large models have excluded much of the research community. BLOOM addresses this access gap with a collaboratively developed 176-billion-parameter multilingual model and documentation of its design process.

1. Introduction

  • Pretrained language models often improve performance with less labeled data, can perform useful tasks without further training, and tend to benefit from increased scale.The passage describes scaling gains as sometimes predictable and sometimes sudden.Source: §1 · pp. 3–4
  • Training costs and limited public releases have excluded much of the research community, while most large language models have primarily used English-language text.The passage also notes environmental concerns about large-model training and cites Chinese- and Korean-language exceptions.Source: §1 · p. 4
  • BLOOM is a 176-billion-parameter model trained on 46 natural and 13 programming languages, developed by hundreds of researchers.The paper describes its design across the training dataset, architecture and objective, and distributed-learning engineering, as well as an analysis of its capabilities.Source: §1 · p. 4

2. Background

The background traces language modeling from next-token prediction through Transformer-based and prompted models, outlines social concerns about LLM development, and describes BigScience’s collaborative organization and ethical commitments.

2.1 Language Modeling

  • Autoregressive language modeling predicts each next token from preceding tokens; Transformers later outperformed recurrent networks and became the de facto language-model architecture.Earlier n-gram models grew exponentially with sequence length and could not assign probabilities to unseen token sequences.Source: §2.1 · pp. 4–5
  • Transfer learning pretrains a model before downstream finetuning, while few- and zero-shot approaches use pretrained models without subsequent task-specific training, often through prompts and demonstrations.Prompts provide natural-language task descriptions and can include examples of input-output behavior.Source: §2.1 · p. 5
  • Concentrated resources, high computational and carbon costs, and limited stakeholder input raise concerns about access, emissions, governance, and whose values guide LLM development.The text also warns that industry-driven narratives can inflate expectations and misdirect research and policy priorities.Source: §2.1 · pp. 5–6

2.2 BigScience

  • BigScience coordinated BLOOM as an open research collaboration: over 1,200 people registered, hundreds contributed to released artifacts, and 30 working groups organized project research.Participants came from varied technical and social-science backgrounds, and 38 countries were represented.Source: §2.2 · p. 6, Figure 1 · p. 7
  • BigScience used a collaboratively designed Ethical Charter and research on regulations beyond the US to guide the project, emphasizing inclusivity, diversity, openness, reproducibility, and responsibility.These values were reflected in dataset curation, modeling, engineering, evaluation, and social-impact work.Source: §2.2 · p. 7

3. BLOOM

This section describes the choices and processes behind BLOOM’s training data, curation and governance, prompted finetuning data, architecture, and multilingual tokenization. It also details distributed training and release choices, resource use, training stability, and carbon estimates.

3.1 Training Dataset

  • ROOTS combines 498 datasets into 1.61 terabytes spanning 46 natural and 13 programming languages, with language inclusion and source selection guided by community expertise.The corpus also included OSCAR, which constituted 38% of its contents.Source: §3.1 · p. 7, §3.1.2 · pp. 10–11

3.1.3 Data Preprocessing

  • Curation aimed to counter opaque, heuristic filtering by prioritizing human involvement and local and language expertise in data selection and documentation.Quality indicators targeted text written by humans for humans, with language-specific thresholds and manually selected indicators; the team also removed near-duplicates and redacted identifiable information in OSCAR.Source: §3.1 · p. 9, §3.1.3 · pp. 12–13

3.1.1 Data Governance

  • BigScience pursued data governance that prioritized rights-holder agency, but used practical measures including seeking provider permission, keeping sources traceable, and releasing sources compositely.The project could distribute 223 of ROOTS’s 498 components, subject to licensing, privacy, and custodian agreements.Source: §3.1.1 · pp. 9–10

3.1.4 Prompted Datasets

  • BLOOMZ was trained on xP3, a prompted-task collection covering 83 datasets, 46 languages, and 16 tasks; xP3mt additionally provided machine-translated prompts.The xP3 language distribution mirrors ROOTS (Figure 4).Source: Figure 4 · p. 13, §3.1.4 · p. 14

3.2.1 Design Methodology

  • Architecture choices were ablated at smaller scales and evaluated for zero-shot generalization, while mixture-of-experts and state-space architectures remained out of scope.The team favored model families with scaling evidence and public tooling; it cited limited suitable GPU codebases for mixture-of-experts and underperformance on natural-language tasks at the time for state-space models.Source: §3.2.1 · pp. 14–15

3.2.2 Architecture and Pretraining Objective

  • Causal decoder-only models performed best immediately after pretraining in the architecture and objective evaluation, supporting BLOOM’s selection of that design.The study also found these models could be adapted more efficiently after pretraining to a non-causal architecture and objective.Source: §3.2.2 · p. 15

3.2.3 Modeling Details

  • BLOOM adopted ALiBi, which improved training smoothness and downstream performance over learned and rotary embeddings, and embedding-layer normalization to mitigate training instability.The layer normalization penalized zero-shot generalization in preliminary experiments; those experiments used float16, whereas final training used bfloat16.Source: §3.2.3 · p. 16

3.3 Tokenization

  • Tokenizer design targeted no more than 10 percentage points of fertility degradation versus monolingual tokenizers; the final vocabulary contained 250,680 items.After duplicate lines were removed from tokenizer training data, the team used language sampling ratios matching the training data; 200 vocabulary items were reserved for possible future uses.Source: §3.3 · pp. 17–18
  • BLOOM’s byte-level BPE starts from bytes to avoid unknown tokens and maximize vocabulary sharing, while text is left unnormalized to preserve generality.Pre-tokenization preserves spaces and line breaks, avoids English-centric splits and does not split numbers, which caused issues in Arabic and code; Unicode normalization reduced fertility by no more than 0.8% across considered languages.Source: §3.3 · p. 18

3.4.1 Hardware

  • 3.5 months and 1,082,990 compute hours were used to train BLOOM on 384 A100 GPUs across 48 nodes, with four spare nodes maintained for hardware failures.The system used Jean Zay, with intra-node NVLink and inter-node Omni-Path links.Source: §3.4.1 · p. 18

3.4.2 Framework; 3.4.4 Fused CUDA Kernels

  • 156 TFLOPs in the fastest A100 configuration reached half the 312-TFLOPs theoretical peak using combined data, tensor, pipeline, and ZeRO stage 1 parallelism.Megatron-DeepSpeed combined the approaches to scale training across hundreds of GPUs. Custom fused CUDA kernels optimized LayerNorm, scaling, masking, softmax, and GeLU operations to reduce memory-transfer overhead.Source: §3.4.2 · pp. 19–20, §3.4.4 · p. 20

3.4.3 Floating Point Format

  • Bfloat16 mixed-precision training resolved the instability problem seen in earlier 104B-parameter experiments using IEEE float16 on V100 GPUs.Gradient accumulation and softmax were computed in float32, while other operations used lower precision.Source: §3.4.3 · p. 20

3.4.5 Additional Challenges

  • Hardware failures averaged 1–2 GPUs per week, but spare nodes and checkpoints every three hours kept throughput from being significantly affected.Data-loader deadlocks and disk-space issues caused 5–10-hour downtimes; the team reported one loss spike, from which the model recovered swiftly.Source: §3.4.5 · pp. 20–21

3.5 Training; Multitask Finetuning

  • BLOOM training used a cosine learning-rate decay over 410B tokens with 375M warmup tokens, while large models received 25B additional tokens on repeated data.ROOTS contained around 341B tokens; because warmup plus decay tokens exceeded the available training tokens, the learning-rate decay endpoint was never reached. BLOOMZ retained BLOOM architecture hyperparameters, was finetuned for 13B tokens, and its best checkpoint was selected on a separate validation set; contrastive finetuning produced embedding models for multilingual retrieval and semantic similarity.Source: §3.5 · p. 22, Multitask Finetuning · p. 22

3.5.1 Carbon Footprint

  • 81 tons of CO2eq were attributed to BLOOM training, with 25 tons from training energy and 45 tons from idle equipment and cluster consumption.BLOOM used 433 MWh versus OPT’s 324 MWh, yet its training emissions were 25 tons versus OPT’s 70 tons, alongside grid intensities of 57 versus 231 gCO2eq/kWh. Final training accounted for approximately 37% of total project-computation emissions; API deployment on a 16-GPU GCP instance was estimated at 20 kg CO2eq per day, varying by use case.Source: §3.5.1 · p. 23, Table 4 · p. 23

3.6 Release

  • BLOOM was released with a Model Card and a no-charge Responsible AI License that separates code and model licensing and imposes 13 behavioral-use restrictions.The source code is under Apache 2.0; the model license permits use subject to its terms and explicitly defines downstream use including prompting, finetuning, distillation, logits, and probability distributions.Source: §3.6 · p. 24

4. Evaluation · 4.1 Experimental Design · SuperGLUE

BLOOM was evaluated with realistic zero- and few-shot prompts, alongside multitask-finetuned evaluations, across SuperGLUE and other tasks. The section describes prompt design, evaluation infrastructure, and task-specific protocols.

4. Evaluation

  • The broader evaluation targeted zero- and few-shot performance across SuperGLUE, translation, and summarization, as well as code generation, text embeddings, multilingual probing, and multitask finetuning.The authors selected prompt-based settings because prompt adaptation and in-context learning were more common than finetuning for models at this scale.Source: §4 · p. 24

4.1.1 Prompts

  • Prompts were created before BLOOM’s release without model-based refinement to approximate reproducible, realistic zero- or one-shot use rather than best-case prompt tuning.The authors argue that trial-and-error prompt refinement is harder to reproduce and less representative of ordinary use or true zero-shot learning.Source: §4.1.1 · p. 25
  • The evaluation suite generated multiple prompts per task with promptsource (Bach et al., 2022), following crowdsourced prompt generation by Sanh et al. (2022), with peer review for clarity and consistency.Prompt length and style varied substantially.Source: §4.1.1 · p. 25

4.1.2 Infrastructure

  • The Prompted Language Model Evaluation Harness extends EleutherAI’s harness with promptsource (Bach et al., 2022) and was released as an open-source library.The framework ran experiments and aggregated results.Source: §4.1.2 · p. 25

SuperGLUE

  • The SuperGLUE evaluation used seven English-only tasks, five randomly sampled prompts per task, and maximum log likelihood over candidate label strings for predictions.The remaining tasks were excluded because they required an order of magnitude more compute than the selected tasks combined; the subset supports comparison with prior English-only work.Source: SuperGLUE · p. 26
  • For SuperGLUE, T0 (Sanh et al., 2022) was noted as an exception in reporting zero- and one-shot results, but its instruction tuning made it not directly comparable to BLOOM or OPT.The selected tasks were English-only and included to facilitate comparison with prior work, which had mainly focused on English-only models.Source: SuperGLUE · p. 26
  • Translation evaluation covered WMT14 en↔fr and en↔hi, Flores-101, and DiaBLa, using sacrebleu BLEU with dataset-specific tokenization and greedy decoding.Generation stopped at EOS or, for one-shot cases, additionally at the specified separator; maximum lengths were 64 tokens for WMT14 and 512 for Flores-101 and DiaBLa.Source: SuperGLUE · p. 26
  • WikiLingua summarization tested source-language generation in nine languages, including Arabic, English, Spanish, French, Hindi, Indonesian, Portuguese, Vietnamese, and Chinese.This design examined BLOOM’s multilingual summarization ability rather than limiting evaluation to English output.Source: Summarization · p. 26

Summarization

The section describes multilingual summarization metrics and evaluation procedures, then identifies baseline models used where they support the evaluation language.

Summarization

  • Summarization is evaluated with ROUGE-2, ROUGE-L, and Levenshtein distance, using a Flores-101 SentencePiece tokenizer, 3,000 uniformly sampled GEM test examples, and the MT decoding procedure.The authors note minimal performance differences between the subsamples and full test sets.Source: Summarization · pp. 26–27

4.1.4 Baseline Models

4.2 SuperGLUE · 4.3 Machine Translation

BLOOM’s results vary by task and prompting: it shows signal on SuperGLUE entailment and can translate competently with suitable prompts, while multilingual translation quality is uneven for underrepresented languages. Across SuperGLUE and translation, one-shot context can improve results, though DiaBLa’s automatic scores do not clearly establish a benefit from dialogue context.

4.2 SuperGLUE

  • BLOOM gains more than comparable models from zero-shot to one-shot SuperGLUE prompting, generally matching or surpassing OPT despite often trailing it zero-shot.Performance increases are slight and inconsistent overall, while variability across prompts and models falls in the one-shot setting.Source: §4.2 · p. 28, Figure 7 · p. 28
  • On SuperGLUE, BLOOM and the compared models perform well above chance on BoolQ and CB, while average performance across prompts on other tasks hovers around chance.T0 is an exception with strong performance, but its multitask fine-tuning makes it not directly comparable to the other models.Source: §4.2 · pp. 27–28, Figure 7 · p. 28
  • Across model scales, BLOOM and OPT improve only very slightly, with signal appearing only above 2 billion parameters and no consistent family-wide difference.In one-shot tests, BLOOM-176B leads OPT-175B on Ax-b, CB, WSC, and WiC, and matches it on the other tasks.Source: §4.2 · p. 28, Figure 8 · p. 29

4.3 Machine Translation

  • The machine-translation evaluations cover WMT zero- and one-shot tests, DiaBLa dialogue-context tests, and one-shot Flores-101 translation across resource levels and language directions.The Flores tests use the “xglm-source+target” prompt with a random dev-set example; language pairs are grouped by resource level, including related Romance pairs.Source: §4.3.1 · p. 29, §4.3.2 · p. 30, §4.3.3 · p. 31

4.3.1 WMT

  • M2M-100 scored 43.8 BLEU for English→French and 40.4 for French→English, versus BLOOM’s 34.2 and 35.4 in one-shot WMT translation.The more verbose prompts tended to perform best; “version-target” was consistently better, while “gpt3-target” and “xglm-source+target” performed poorly, especially zero-shot. Over-generation and incorrect output language were prominent zero-shot problems, both greatly improving with more few-shot examples.Source: §4.3.1 · pp. 29–30, Table 6 · p. 30

4.3.2 DiaBLa

  • DiaBLa’s automatic scores are inconclusive: previous-dialogue context raises BLEU relative to a random example but lowers COMET, although predictions show evidence of context-sensitive translation choices.The comparison used the “xglm-source+target” prompt in a one-shot setting and evaluated both original outputs and outputs truncated to address over-generation.Source: §4.3.2 · p. 30

4.3.3 Flores

  • In 1-shot translation, BLOOM’s results were often comparable to and sometimes better than supervised 615M-parameter M2M-100, with good results across high-resource and high-to-mid-resource pairs, even across scripts (Fan et al., 2021).Results were also comparable in many cases to 32-shot AlexaTM results for high-resource language pairs.Source: §4.3.3 · p. 32
  • Flores-101 results are poor for Swahili–Yoruba, whose languages each had fewer than 50k training tokens, but good across Romance pairs, including unseen Galician.The contrast raises a concern about quality for underrepresented low-resource languages that were included in training.Source: §4.3.3 · p. 32

4.4 Summarization

BLOOM achieves stronger one-shot multilingual summarization performance than OPT-175B, with performance increasing alongside model size. The authors report ROUGE-2 for comparability but note that it can understate summary quality.

  • BLOOM outperforms OPT-175B on one-shot multilingual summarization, and performance increases with model parameter count (Figure 9).Source: §4.4 · p. 32
  • The authors suspect BLOOM’s multilingual-focused training contributes to its stronger multilingual summarization performance.Source: §4.4 · p. 32
  • ROUGE-2 is reported for comparability with prior work because alternatives for generation evaluation are lacking, but it can understate summary quality.Source: §4.4 · p. 32

4.5 Code Generation · 4.6 HELM benchmark

On HumanEval, pretrained BLOOM performs similarly to similarly sized GPT models trained on the Pile, while Codex is significantly stronger and multitask-finetuned BLOOMZ shows no significant improvement. On HELM’s 5-shot English-only tasks, BLOOM is roughly on par with previous-generation English-only models, behind more recent monolingual models, and performs differently across calibration, robustness, and fairness measures.

4.5 Code Generation

  • On HumanEval, pretrained BLOOM models perform similarly to similarly sized GPT models trained on the Pile.ROOTS contains around 11% code, compared with around 13% in the Pile; both corpora have similar code sources and proportions.Source: §4.5 · p. 32
  • Codex models, which were solely finetuned on code, are significantly stronger than other models.Source: §4.5 · p. 32
  • Multitask-finetuned BLOOMZ models do not significantly improve over BLOOM, possibly because xP3 lacks substantial pure code-completion data.Instead, xP3 includes code-related tasks such as estimating the time complexity of a Python code snippet.Source: §4.5 · p. 32

4.6 HELM benchmark

  • On HELM’s 5-shot English-only tasks, BLOOM is roughly on par with GPT3-davinci v1 and J1-Grande v1, but behind newer monolingual models.The newer models named are InstructGPT davinci v2, Turing NLG v2, Anthropic-LM v4-s3, and OPT.Source: §4.6 · p. 33
  • On HELM, BLOOM is not very well calibrated but is quite robust.Source: §4.6 · p. 33
  • On HELM, BLOOM is among the best models for fairness, slightly more toxic than average in English, and average for bias.Source: §4.6 · p. 33

4.7 Multitask Finetuning

Multilingual multitask finetuning on xP3 significantly improves BLOOM’s zero-shot performance on the depicted held-out tasks. The section contrasts this result with pretrained performance near random baselines and explains why T0 performs poorly on multilingual datasets.

4.7 Multitask Finetuning

  • 33% for NLI (XNLI) and 50% for coreference resolution (XWinograd) are the random baselines that pretrained BLOOM and XGLM perform near.Source: §4.7 · p. 33
  • Multilingual multitask finetuning with xP3 significantly improves BLOOMZ zero-shot performance on held-out NLI, coreference, and sentence-completion tasks.The comparison includes pretrained BLOOM and XGLM and multitask-finetuned BLOOMZ, T0, and mTk-Instruct.Source: §4.7 · pp. 33–34
  • T0 performs badly on the depicted multilingual datasets because it is a monolingual English model.Source: §4.7 · p. 34
  • xP3-finetuned models also outperform T0 on English datasets when controlling for size and architecture, likely because xP3 has more diverse datasets and prompts than P3 (Muennighoff et al., 2022b; Chung et al., 2022).Source: §4.7 · p. 34

4.8 Embeddings

SGPT-BLOOM embeddings are evaluated on two multilingual MTEB datasets, where the 7.1B MS-MARCO model leads several classification and semantic textual similarity splits.

4.8 Embeddings

  • On two multilingual MTEB datasets, SGPT-BLOOM-7.1B-msmarco[36] achieves state-of-the-art performance on several classification and semantic textual similarity splits.The models use contrastive finetuning.Source: §4.8 · pp. 34–35
  • SGPT-BLOOM-7.1B-msmarco[36] is an order of magnitude larger than the displayed multilingual MiniLM[37] and MPNet[38] models.Source: §4.8 · p. 35
  • SGPT-BLOOM-1.7B-nli[39] performs significantly worse, likely because it has fewer parameters and shorter finetuning on a much smaller dataset.The passage identifies NLI as much smaller than MS-MARCO.Source: §4.8 · p. 35
  • ST5-XL[40], the largest non-BLOOM model at 1.2 billion parameters, performs poorly on non-English data because it is English-only.The displayed languages are part of BLOOM's pretraining corpus; more languages and datasets are available on the MTEB leaderboard[41].Source: §4.8 · pp. 35–36

4.9 Multilingual Probing

BLOOM’s multilingual probing results show that both model sizes outperform count-based baselines, with performance varying by language and morphosyntactic feature. The analysis also identifies language- and data-related correlations and open questions about generalization and representation development.

4.9.1 Method

  • The study probes 17 languages from 7 families and 38 morphosyntactic features using layer-pooled sentence embeddings and logistic-regression classifiers.It uses the 1.7B and 176B BLOOM models, evaluates weighted F1 across three random-seed runs, and compares against random guessing and TF-IDF n-gram baselines.Source: §4.9.1 · pp. 37–38

4.9.2 Results

  • BLOOM-1B7 performs on par with or better than BLOOM, and both models outperform count-based baselines across the probing results.The reported averages cover probing tasks and experiment runs within each language.Source: Table 12 · p. 39, §4.9.2 · p. 39
  • Both models infer Mood and Person well across languages, Number, NumType, and Voice moderately, and other categories less well; Bengali, Wolof, and Yoruba score lowest.The authors suggest that categories with more language-dependent values, such as Case, may be harder to infer than categories with more shared values.Source: Figure 12 · p. 39, §4.9.2 · p. 40
  • BLOOM-1B7 results correlate strongly with language family and probing and pretraining dataset sizes, while BLOOM-1B7 scores significantly higher than BLOOM (p < 0.01).BLOOM is reported to perform more stably across languages regardless of pretraining data amount, possibly indicating better generalization with more parameters.Source: §4.9.2 · p. 40, Table 13 · p. 40
  • Future work includes probing languages outside pretraining, studying under-resourced languages, and examining layer-specific representations and how linguistic properties emerge during pretraining.The authors also caution that BLOOM-1B7’s stronger average results and stronger dataset-size correlations may imply weaker generalization to under-resourced languages than the larger model.Source: §4.9.2 · pp. 40–41

4.10 Bias

BLOOM’s CrowS-Pairs prompt accuracy was close to .50 in English and French, suggesting limited overall bias, though accuracy differed significantly from 50 in both languages and several bias categories. The evaluation is preliminary: its dataset validation and language coverage limit what it establishes about broader use.

  • The evaluation adapted multilingual CrowS-Pairs—revised English pairs and a French version—to autoregressive models, using prompts that ask which minimal-pair statement seems likely and realistic.The dataset assesses systematic preference for stereotyped over non-stereotyped statements.Source: §4.10 · p. 41
  • CrowS-Pairs accuracy was homogeneous across bias categories, unlike prior masked-language-model findings, yet differed significantly from 50 overall in both languages and in several categories.The category results are averaged over eight runs; asterisks indicate significance at p < .05.Source: §4.10 · pp. 41–42, Table 14 · p. 42
  • BLOOM’s overall prompt accuracy was close to .50 in English and French, suggesting limited overall bias and similar behavior across the two languages.Figure 13 also shows results for the two smallest BLOOM models and monolingual GPT models of comparable size.Source: §4.10 · p. 41, Figure 13 · p. 42
  • The CrowS-Pairs version addresses some validity issues raised by Blodgett et al. (2021), adds 200 stereotype pairs based on French speakers, and had results not significantly different from the original in Névéol et al. (2022).Source: §4.10 · p. 42
  • CrowS-Pairs’ original validation does not naturally apply to this evaluation, making comparison with other results difficult; stronger assessment requires other bias measures and coverage of all model languages.Very little multilingual bias-assessment material is available.Source: §4.10 · p. 43
  • The evaluation covers only situations, languages, and variants in multilingual CrowS-Pairs; curated training resources may unevenly capture language variation and thereby affect equitable representation and legitimize some variants over others.The authors distinguish these findings from broader model use and point to Raji et al. (2021) for further exploration.Source: §4.10 · p. 43

5. Conclusion

BLOOM is a 176B-parameter open-access multilingual model developed by hundreds of researchers and trained on the Jean Zay supercomputer. The authors report competitive performance that improves after multitask finetuning and hope the release and project experience will enable new research and collaboration.

5. Conclusion

  • BLOOM is a 176B-parameter open-access multilingual model whose competitive performance improves after multitask finetuning.BigScience, a collaboration of hundreds of researchers, trained it on the French government-funded Jean Zay supercomputer for 3.5 months.Source: §5 · p. 43
  • The authors hope BLOOM’s release will unlock applications and research directions, while their account of BigScience will help researchers organize collaborative projects and broaden participation.They emphasize that such projects can achieve results beyond an individual research group and enable people with different backgrounds to share ideas.Source: §5 · p. 43

6. Contributions

Authors are assigned to one or more categories according to their project contributions. Names are alphabetical by first name except for randomly shuffled Major Contributors and Organization, where Thomas Wolf is intentionally last.

Major Contributors

  • Major Contributors lists people essential to BLOOM or those who spent more than 20% of their time on the BigScience effort.The category’s author order is randomly shuffled, except that Teven Le Scao is intentionally listed first.Source: §6 · p. 43

Dataset and Tokenization

  • Dataset contributors handled data sourcing, organization, and processing, while Tokenization contributors built the BLOOM tokenizer.The Dataset category includes authors of Lauren¸con et al. (2022), McMillan-Major et al. (2022), and Jernite et al. (2022); Tokenization includes authors of Mielke.Source: §6 · p. 44

Prompt Engineering and Architecture and Objective

  • Prompt Engineering contributors wrote, edited, and reviewed dataset prompt templates, while Architecture and Objective contributors ran experiments to determine BLOOM’s architecture and training objective.The categories include authors of Sanh et al. (2022), Bach et al. (2022), Muennighoff et al. (2022b), Wang et al. (2022a), and Le Scao et al. (2022).Source: §6 · p. 44

Engineering and Evaluation and interpretability

  • Engineering contributors supported BLOOM’s code and training infrastructure on Jean Zay, while Evaluation and interpretability contributors helped evaluate the model.The Evaluation and interpretability category also includes authors of Talat et al. (2022).Source: §6 · p. 44

Broader Impacts, Applications, and Organization

  • Broader Impacts covers the ethical charter, license, model card, privacy, social impacts, and carbon footprint; Applications covers application-focused working groups; Organization covers BigScience coordination.Applications includes authors of Fries et al. (2022b), Fries et al. (2022a), and De Toni et al. (2022); Organization includes authors of Akiki.Source: §6 · p. 44

Appendix A. Prompts

Appendix A collects evaluation prompts, with raw templates and applied examples; double curly brackets mark sample content inserted into raw prompts, and the prompts are also available in PromptSource (Bach et al., 2022).

Appendix A. Prompts

  • The appendix supplies evaluation prompts as raw templates and applied examples, using double curly brackets for sample content.It also points readers to PromptSource (Bach et al., 2022).Source: Appendix A · p. 65

A.1.1 Data example; A.2.1 Data example; GPT-3-prompt-with-label

A.3.1 Data example; A.4.1 Data example; A.5.1 Data example

A.6.1 Data example; A.7.1 Data example

  • A pronoun-resolution example selects “The city councilmen” as the sentence completion, while another example chooses the cause “It was fragile” for bubble-wrapped packaging.Source: §A.6.1 · p. 69, §A.7.1 · p. 70

A.7.2 Prompts

  • A.7’s reusable causal prompt template offers two answer choices and inserts “because” for cause questions or “so” otherwise.Source: §A.7.2 · p. 70

A.8.1 Data example; A.9 WMT; A.9.1 Data example; a_good_translation-l1-l2-source+target

  • The appendix notes that XStoryCloze and Story Cloze samples are not public, and its WMT prompts cover zero-shot and one-shot English–French and English–Hindi directions with language-specific variants.The WMT example presents a source sentence followed by a requested target-language translation.Source: §A.8.1 · p. 71, §A.9 · p. 71, §A.9.1 · p. 71

A.10 DiaBLa; A.10.1 Data example; xglm-source+target

A.11 Flores-101 (MT); A.11.1 Data example; xglm-French-Catalan-source+target; A.12.1 Data example; demontraste_or_violate

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