Paper links

Work in progress: this part of the notes is still being revised.

Papers

The notes cite the original papers where their ideas arise. This index collects the principal ones by topic; the chapters give further references inline.

Tokenization and n-gram models

WorkIdea developed in the module
Gage, A New Algorithm for Data Compression (1994), and Sennrich, Haddow, and Birch, Neural Machine Translation of Rare Words with Subword Units (2016)Byte-pair encoding, from a compression algorithm to subword vocabularies for translation (chapters 1 and 15).
Schuster and Nakajima, Japanese and Korean Voice Search (2012)WordPiece, which chooses merges by the likelihood of the training data (chapter 1).
Kudo, Subword Regularization: Improving Neural Network Translation Models with Multiple Subword Candidates (2018)The unigram language model tokenizer and the sampling of segmentations (chapter 1).
Kudo and Richardson, SentencePiece: A Simple and Language Independent Subword Tokenizer and Detokenizer for Neural Text Processing (2018)BPE and unigram tokenizers trained directly on raw text, with spaces as an ordinary symbol (chapter 1).
Petrov et al., Language Model Tokenizers Introduce Unfairness between Languages (2023)Token counts for the same text that differ by up to a factor of 15 across languages (chapter 1).
Xue et al., ByT5: Towards a Token-Free Future with Pre-Trained Byte-to-Byte Models (2022)A transformer trained directly on UTF-8 bytes, without a tokenizer (chapter 1).
Shannon, A Mathematical Theory of Communication (1948), and Prediction and Entropy of Printed English (1951)Approximations to English of increasing order, and the entropy of English estimated from human guessing (chapter 2).
Good, The Population Frequencies of Species and the Estimation of Population Parameters (1953)Good–Turing estimation from the count of counts (chapter 2).
Katz, Estimation of Probabilities from Sparse Data for the Language Model Component of a Speech Recognizer (1987)Backoff with Good–Turing discounting (chapter 2).
Kneser and Ney, Improved Backing-Off for M-Gram Language Modeling (1995), and Chen and Goodman, An Empirical Study of Smoothing Techniques for Language Modeling (1999)Kneser–Ney smoothing with continuation counts, and its modified form with three discounts (chapter 2).

Word embeddings

WorkIdea developed in the module
Harris, Distributional Structure (1954)The distributional hypothesis (chapter 3).
Church and Hanks, Word Association Norms, Mutual Information, and Lexicography (1990)Pointwise mutual information between words and their contexts (chapter 3).
Mikolov et al., Efficient Estimation of Word Representations in Vector Space (2013), and Distributed Representations of Words and Phrases and Their Compositionality (2013)Word2vec: the skip-gram model and negative sampling (chapter 3).
Levy and Goldberg, Neural Word Embedding as Implicit Matrix Factorization (2014)Skip-gram with negative sampling factorizes a shifted PMI matrix (chapter 3).
Levy, Goldberg, and Dagan, Improving Distributional Similarity with Lessons Learned from Word Embeddings (2015)With matched design choices, count-based and predictive vectors perform alike (chapter 3).
Pennington, Socher, and Manning, GloVe: Global Vectors for Word Representation (2014)An explicit weighted factorization of log co-occurrence counts (chapter 3).
Bojanowski et al., Enriching Word Vectors with Subword Information (2017)FastText: word vectors built from character n-grams (chapter 3).
Bolukbasi et al., Man Is to Computer Programmer as Woman Is to Homemaker? Debiasing Word Embeddings (2016)Social biases in embeddings, and projecting out a gender direction (chapter 3).

Transformer language models

WorkIdea developed in the module
Bengio et al., A Neural Probabilistic Language Model (2003)The first neural language model: learned word vectors and a feedforward network over a fixed window (chapters 2 and 4).
Radford et al., Improving Language Understanding by Generative Pre-Training (2018)GPT: a pretrained transformer decoder fine-tuned for downstream tasks (chapters 4 and 5).
Radford et al., Language Models Are Unsupervised Multitask Learners (2019)GPT-2: byte-level BPE, and tasks performed without fine-tuning (chapters 1 and 4).
Brown et al., Language Models Are Few-Shot Learners (2020)GPT-3: 175 billion parameters, 300 billion tokens, and few-shot prompting (chapters 4, 6, and 9).
OpenAI, GPT-4 Technical Report (2023)Calibration of the pretrained model, and final loss predicted from much smaller runs (chapters 4 and 7).
Touvron et al., Llama 2: Open Foundation and Fine-Tuned Chat Models (2023)An open reference architecture, and post-training with rejection sampling, PPO, and separate reward models (chapters 4 and 11).
Llama Team, The Llama 3 Herd of Models (2024)The tokenizer, document masking, and 15.6-trillion-token data mixture of a current open model (chapters 1, 4, and 6).
Shazeer et al., Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layer (2017), and Fedus, Zoph, and Shazeer, Switch Transformers: Scaling to Trillion Parameter Models with Simple and Efficient Sparsity (2022)Mixture-of-experts layers, top-\(k\) routing, and the load-balancing loss (chapter 4).
DeepSeek-AI, DeepSeek-V3 Technical Report (2024)Many small experts, balancing without an auxiliary loss, and latent attention at scale (chapter 4).
Chen et al., Extending Context Window of Large Language Models via Positional Interpolation (2023)Extending rotary position embeddings beyond the training length (chapter 4).
Liu et al., Lost in the Middle: How Language Models Use Long Contexts (2023)Information in the middle of a long context is used least (chapter 4).

Pretraining and transfer

WorkIdea developed in the module
Peters et al., Deep Contextualized Word Representations (2018)ELMo: contextual word vectors from bidirectional LSTM language models (chapters 3 and 5).
Howard and Ruder, Universal Language Model Fine-Tuning for Text Classification (2018)ULMFiT: fine-tuning a whole pretrained language model, first on the target domain and then on the task (chapter 5).
Devlin et al., BERT: Pre-Training of Deep Bidirectional Transformers for Language Understanding (2019)Masked language modeling and the bidirectional encoder (chapter 5).
Liu et al., RoBERTa: A Robustly Optimized BERT Pretraining Approach (2019)Longer training on more data, without next-sentence prediction (chapter 5).
Clark et al., ELECTRA: Pre-Training Text Encoders as Discriminators Rather than Generators (2020)Replaced-token detection, a training signal at every position (chapter 5).
Raffel et al., Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer (2020)T5: span corruption, the text-to-text format, and the C4 corpus (chapters 5 and 6).
Wang et al., GLUE: A Multi-Task Benchmark and Analysis Platform for Natural Language Understanding (2018)The benchmark on which pretrained encoders were compared, and its rapid saturation (chapter 5).
Reimers and Gurevych, Sentence-BERT: Sentence Embeddings Using Siamese BERT-Networks (2019)Sentence embeddings from BERT fine-tuned as a bi-encoder (chapter 5).
Tenney, Das, and Pavlick, BERT Rediscovers the Classical NLP Pipeline (2019)Probing which layers encode which linguistic properties (chapter 5).
Linzen, Dupoux, and Goldberg, Assessing the Ability of LSTMs to Learn Syntax-Sensitive Dependencies (2016)Subject–verb agreement across intervening nouns as a test of syntax (chapters 5 and 16).

Pretraining data

WorkIdea developed in the module
Gao et al., The Pile: An 800GB Dataset of Diverse Text for Language Modeling (2020)A curated mixture of 22 sources (chapter 6).
Penedo et al., The RefinedWeb Dataset for Falcon LLM: Outperforming Curated Corpora with Web Data, and Web Data Only (2023), and The FineWeb Datasets: Decanting the Web for the Finest Text Data at Scale (2024)Filtered and deduplicated web text alone, with every step of the pipeline ablated (chapter 6).
Rae et al., Scaling Language Models: Methods, Analysis & Insights from Training Gopher (2021)Heuristic quality rules that remain a common template (chapter 6).
Lee et al., Deduplicating Training Data Makes Language Models Better (2022)Deduplication reduces memorization and training cost (chapter 6).
Carlini et al., Quantifying Memorization across Neural Language Models (2023)Memorization grows log-linearly with duplication and with model size (chapter 6).
Broder, On the Resemblance and Containment of Documents (1997)MinHash estimates of Jaccard similarity for near-duplicate detection (chapter 6).
Xie et al., DoReMi: Optimizing Data Mixtures Speeds Up Language Model Pretraining (2023)Domain weights learned with a small proxy model (chapter 6).
Muennighoff et al., Scaling Data-Constrained Language Models (2023)The value of repeated data, and a scaling law for several epochs (chapters 6 and 7).
Shumailov et al., AI Models Collapse When Trained on Recursively Generated Data (2024)Model collapse under recursive training on generated text (chapter 6).

Scaling laws

WorkIdea developed in the module
Hestness et al., Deep Learning Scaling Is Predictable, Empirically (2017)Test loss as a power law in the amount of data, across domains (chapter 7).
Kaplan et al., Scaling Laws for Neural Language Models (2020)Power laws in parameters, data, and compute for transformer language models (chapters 4 and 7).
Hoffmann et al., Training Compute-Optimal Large Language Models (2022)The joint law in model size and data, and compute-optimal allocation (chapter 7).
Porian et al., Resolving Discrepancies in Compute-Optimal Scaling of Language Models (2024)Why the Kaplan and Chinchilla allocations differ (chapter 7).
Besiroglu et al., Chinchilla Scaling: A Replication Attempt (2024)A refit of the Chinchilla law from data reconstructed from the paper’s figures (chapter 7).
Sardana et al., Beyond Chinchilla-Optimal: Accounting for Inference in Language Model Scaling Laws (2024)Counting inference favors smaller models trained on more data (chapter 7).
Yang et al., Tensor Programs V: Tuning Large Neural Networks via Zero-Shot Hyperparameter Transfer (2022)μP: hyperparameters tuned on a small proxy and transferred to a large model (chapter 7).
Wei et al., Emergent Abilities of Large Language Models (2022), and Schaeffer, Miranda, and Koyejo, Are Emergent Abilities of Large Language Models a Mirage? (2023)Abrupt gains with scale, and how much of them the choice of metric creates (chapter 7).

Decoding and inference

WorkIdea developed in the module
Wu et al., Google’s Neural Machine Translation System: Bridging the Gap between Human and Machine Translation (2016)A production neural translation system and the length penalty for beam search (chapters 8 and 15).
Koehn and Knowles, Six Challenges for Neural Machine Translation (2017)The beam search curse and the weaknesses of early neural translation (chapters 8 and 15).
Stahlberg and Byrne, On NMT Search Errors and Model Errors: Cat Got Your Tongue? (2019)Exact search shows that the most probable translation is often the empty string (chapter 8).
Holtzman et al., The Curious Case of Neural Text Degeneration (2020)Degeneration under maximization, and nucleus (top-\(p\)) sampling (chapter 8).
Fan, Lewis, and Dauphin, Hierarchical Neural Story Generation (2018)Top-\(k\) sampling (chapter 8).
Willard and Louf, Efficient Guided Generation for Large Language Models (2023)Constrained decoding with the allowed tokens precomputed for each automaton state (chapter 8).
Leviathan, Kalman, and Matias, Fast Inference from Transformers via Speculative Decoding (2023), and Chen et al., Accelerating Large Language Model Decoding with Speculative Sampling (2023)Speculative decoding: a draft model proposes tokens and the target model verifies them without changing its distribution (chapter 8).
Kwon et al., Efficient Memory Management for Large Language Model Serving with PagedAttention (2023)The key–value cache stored in blocks allocated on demand (chapter 8).

In-context learning and prompting

WorkIdea developed in the module
Zhao et al., Calibrate Before Use: Improving Few-Shot Performance of Language Models (2021)Majority-label, recency, and common-token biases, and contextual calibration (chapter 9).
Lu et al., Fantastically Ordered Prompts and Where to Find Them: Overcoming Few-Shot Prompt Order Sensitivity (2022)The sensitivity of few-shot accuracy to the order of demonstrations (chapter 9).
Min et al., Rethinking the Role of Demonstrations: What Makes In-Context Learning Work? (2022), and Wei et al., Larger Language Models Do In-Context Learning Differently (2023)What demonstrations convey: format and label space for smaller models, the input–label mapping for larger ones (chapter 9).
Xie et al., An Explanation of In-Context Learning as Implicit Bayesian Inference (2022)In-context learning as inference over latent concepts (chapter 9).
Garg et al., What Can Transformers Learn In-Context? A Case Study of Simple Function Classes (2022), and von Oswald et al., Transformers Learn In-Context by Gradient Descent (2023)Transformers trained on regression prompts, and linear attention layers that perform gradient steps (chapter 9).
Olsson et al., In-Context Learning and Induction Heads (2022)Induction heads and the phase change in which they form (chapter 9).
Chan et al., Data Distributional Properties Drive Emergent In-Context Learning in Transformers (2022)Burstiness and many rare classes in the training data produce in-context learning (chapter 9).

Fine-tuning and adaptation

WorkIdea developed in the module
Wei et al., Finetuned Language Models Are Zero-Shot Learners (2022)FLAN: instruction tuning on NLP datasets rewritten as instructions (chapter 10).
Wang et al., Self-Instruct: Aligning Language Models with Self-Generated Instructions (2023)Instruction data generated by a model from a few seed examples (chapter 10).
Zhou et al., LIMA: Less Is More for Alignment (2023)Instruction tuning on 1,000 curated examples (chapter 10).
Houlsby et al., Parameter-Efficient Transfer Learning for NLP (2019)Adapters: small bottleneck networks trained inside a frozen model (chapter 10).
Li and Liang, Prefix-Tuning: Optimizing Continuous Prompts for Generation (2021)Soft prompts: trained key and value vectors prepended at every layer (chapter 10).
Hu et al., LoRA: Low-Rank Adaptation of Large Language Models (2022)Low-rank updates to frozen weight matrices (chapter 10).
Aghajanyan, Zettlemoyer, and Gupta, Intrinsic Dimensionality Explains the Effectiveness of Language Model Fine-Tuning (2021)Fine-tuning succeeds within a low-dimensional subspace (chapter 10).
Dettmers et al., QLoRA: Efficient Finetuning of Quantized LLMs (2023)LoRA on a base model stored in 4-bit precision (chapter 10).
Ilharco et al., Editing Models with Task Arithmetic (2023)Task vectors, added and negated in weight space (chapter 10).
Kim and Rush, Sequence-Level Knowledge Distillation (2016)Fine-tuning a student on outputs generated by the teacher (chapter 10).

Learning from preferences

WorkIdea developed in the module
Christiano et al., Deep Reinforcement Learning from Human Preferences (2017)A reward model learned from human comparisons (chapter 11).
Stiennon et al., Learning to Summarize from Human Feedback (2020)Reinforcement learning from human feedback applied to summarization (chapter 11).
Ouyang et al., Training Language Models to Follow Instructions with Human Feedback (2022)InstructGPT: demonstrations, a reward model, and PPO for a general assistant (chapters 10, 11, and 14).
Bai et al., Training a Helpful and Harmless Assistant with Reinforcement Learning from Human Feedback (2022)Pairwise comparisons of helpfulness and harmlessness in dialogue (chapter 11).
Schulman et al., Proximal Policy Optimization Algorithms (2017), and Ahmadian et al., Back to Basics: Revisiting REINFORCE Style Optimization for Learning from Human Feedback in LLMs (2024)PPO, and simpler estimators that replace the value network by the mean reward of several samples (chapter 11).
Rafailov et al., Direct Preference Optimization: Your Language Model Is Secretly a Reward Model (2023)DPO: a loss on the policy alone, with no separate reward model (chapter 11).
Gao, Schulman, and Hilton, Scaling Laws for Reward Model Overoptimization (2023)Goodhart’s law measured against a gold reward model (chapter 11).
Sharma et al., Towards Understanding Sycophancy in Language Models (2023)Sycophancy learned from human preferences (chapter 11).
Bai et al., Constitutional AI: Harmlessness from AI Feedback (2022)Critiques, revisions, and preferences from a model guided by written principles (chapter 11).

Reasoning and test-time compute

WorkIdea developed in the module
Wei et al., Chain-of-Thought Prompting Elicits Reasoning in Large Language Models (2022), and Kojima et al., Large Language Models Are Zero-Shot Reasoners (2022)Chain-of-thought prompting, with worked demonstrations and with Let’s think step by step alone (chapter 12).
Cobbe et al., Training Verifiers to Solve Math Word Problems (2021)GSM8K, and verifiers that rank sampled solutions (chapters 12 and 14).
Turpin et al., Language Models Don’t Always Say What They Think: Unfaithful Explanations in Chain-of-Thought Prompting (2023)Chains of thought that omit what drove the answer (chapter 12).
Wang et al., Self-Consistency Improves Chain of Thought Reasoning in Language Models (2023)Majority voting over sampled chains of thought (chapter 12).
Lightman et al., Let’s Verify Step by Step (2023)Process reward models that score individual steps (chapter 12).
Snell et al., Scaling LLM Test-Time Compute Optimally Can Be More Effective than Scaling Model Parameters (2024)Test-time computation allocated by difficulty, traded against model size (chapter 12).
Zelikman et al., STaR: Bootstrapping Reasoning with Reasoning (2022)Fine-tuning on the model’s own successful rationales (chapter 12).
Shao et al., DeepSeekMath: Pushing the Limits of Mathematical Reasoning in Open Language Models (2024)GRPO: policy optimization with rewards normalized within a group of samples (chapter 12).
DeepSeek-AI, DeepSeek-R1: Incentivizing Reasoning Capability in LLMs via Reinforcement Learning (2025)Long reasoning learned from verifiable rewards, starting from a base model (chapter 12).

Retrieval, tools, and agents

WorkIdea developed in the module
Robertson and Zaragoza, The Probabilistic Relevance Framework: BM25 and Beyond (2009)BM25 and sparse retrieval (chapter 13).
Karpukhin et al., Dense Passage Retrieval for Open-Domain Question Answering (2020)Dense retrieval with separate question and passage encoders (chapter 13).
Jégou, Douze, and Schmid, Product Quantization for Nearest Neighbor Search (2011), and Malkov and Yashunin, Efficient and Robust Approximate Nearest Neighbor Search Using Hierarchical Navigable Small World Graphs (2020)Compressed vectors and graph indexes for approximate nearest-neighbor search (chapter 13).
Lewis et al., Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks (2020)A retriever and a generator trained jointly, with the passage as a latent variable (chapter 13).
Borgeaud et al., Improving Language Models by Retrieving from Trillions of Tokens (2022)RETRO: retrieval built into the model through cross-attention (chapter 13).
Schick et al., Toolformer: Language Models Can Teach Themselves to Use Tools (2023)A model that learns by itself when to call tools (chapter 13).
Yao et al., ReAct: Synergizing Reasoning and Acting in Language Models (2023)Agents that interleave reasoning with actions and observations (chapter 13).
Jimenez et al., SWE-bench: Can Language Models Resolve Real-World GitHub Issues? (2024)Real repository issues, checked by the repositories’ tests, as a benchmark for agents (chapter 13).
Greshake et al., Not What You’ve Signed Up For: Compromising Real-World LLM-Integrated Applications with Indirect Prompt Injection (2023)Indirect prompt injection (chapter 13).

Evaluation

WorkIdea developed in the module
Hendrycks et al., Measuring Massive Multitask Language Understanding (2021), and Measuring Mathematical Problem Solving with the MATH Dataset (2021)The MMLU and MATH benchmarks (chapter 14).
Chen et al., Evaluating Large Language Models Trained on Code (2021)HumanEval and checking code by execution (chapter 14).
Liang et al., Holistic Evaluation of Language Models (2022)HELM: many metrics beyond accuracy, across many scenarios (chapter 14).
Biderman et al., Lessons from the Trenches on Reproducible Evaluation of Language Models (2024)Evaluation protocols and shared evaluation code (chapter 14).
Zheng et al., Judging LLM-as-a-Judge with MT-Bench and Chatbot Arena (2023)Language models as judges, and their position and verbosity biases (chapter 14).
Chiang et al., Chatbot Arena: An Open Platform for Evaluating LLMs by Human Preference (2024)A leaderboard fitted to crowdsourced pairwise comparisons (chapter 14).
Miller, Adding Error Bars to Evals: A Statistical Approach to Language Model Evaluations (2024)Standard errors and confidence intervals for benchmark scores (chapter 14).

Machine translation and multilingual models

WorkIdea developed in the module
Brown et al., The Mathematics of Statistical Machine Translation: Parameter Estimation (1993)The IBM alignment models trained by EM (chapter 15).
Och and Ney, A Systematic Comparison of Various Statistical Alignment Models (2003)The GIZA++ cascade of alignment models (chapter 15).
Koehn, Och, and Marcu, Statistical Phrase-Based Translation (2003)Phrase-based translation from word alignments (chapter 15).
Sutskever, Vinyals, and Le, Sequence to Sequence Learning with Neural Networks (2014)The encoder–decoder introduced for translation (chapter 15).
Vaswani et al., Attention Is All You Need (2017)The transformer, introduced as a translation model (chapter 15).
Sennrich, Haddow, and Birch, Improving Neural Machine Translation Models with Monolingual Data (2016)Back-translation (chapter 15).
Papineni et al., Bleu: A Method for Automatic Evaluation of Machine Translation (2002)BLEU: clipped n-gram precisions and a brevity penalty (chapter 15).
Rei et al., COMET: A Neural Framework for MT Evaluation (2020), and Freitag et al., Results of WMT22 Metrics Shared Task: Stop Using BLEU – Neural Metrics Are Better and More Robust (2022)Learned metrics and their closer agreement with expert judgments (chapter 15).
Johnson et al., Google’s Multilingual Neural Machine Translation System: Enabling Zero-Shot Translation (2017)One model for many language pairs, and zero-shot translation (chapter 15).
Conneau et al., Unsupervised Cross-Lingual Representation Learning at Scale (2020)XLM-R and the curse of multilinguality (chapter 15).
NLLB Team, No Language Left Behind: Scaling Human-Centered Machine Translation (2022)Translation for 200 languages, including evaluation sets and mined parallel data (chapter 15).

Syntactic parsing

WorkIdea developed in the module
Marcus, Santorini, and Marcinkiewicz, Building a Large Annotated Corpus of English: The Penn Treebank (1993)The treebank on which statistical parsers were trained and compared (chapter 16).
Lari and Young, The Estimation of Stochastic Context-Free Grammars Using the Inside-Outside Algorithm (1990)Learning a probabilistic grammar from unannotated sentences with EM (chapter 16).
Johnson, PCFG Models of Linguistic Tree Representations (1998)Parent annotation and the independence assumptions of treebank grammars (chapter 16).
Collins, Head-Driven Statistical Models for Natural Language Parsing (2003)Lexicalized probabilistic grammars (chapter 16).
Kitaev and Klein, Constituency Parsing with a Self-Attentive Encoder (2018)Neural span scores decoded with CKY-style dynamic programming (chapter 16).
Nivre et al., Universal Dependencies v1: A Multilingual Treebank Collection (2016)Dependency annotation that is consistent across languages (chapter 16).
Nivre, Incrementality in Deterministic Dependency Parsing (2004)The arc-standard transition system (chapter 16).
Chen and Manning, A Fast and Accurate Dependency Parser Using Neural Networks (2014)A neural network in place of sparse features in a transition-based parser (chapter 16).
McDonald et al., Non-Projective Dependency Parsing Using Spanning Tree Algorithms (2005), and Eisner, Three New Probabilistic Models for Dependency Parsing: An Exploration (1996)Graph-based parsing: maximum spanning arborescences, and Eisner’s algorithm for projective trees (chapter 16).
Dozat and Manning, Deep Biaffine Attention for Neural Dependency Parsing (2017)The biaffine arc scorer (chapter 16).
Hewitt and Manning, A Structural Probe for Finding Syntax in Word Representations (2019)Tree distances recovered by a linear transformation of contextual word vectors (chapter 16).