AI Trainer Glossary
Definitions of AI and machine learning terms, written for trainers, not researchers. Every entry includes a plain explanation and a practical note on what it means for your work.
88 terms Updated 2026
A
- Acceptance Rate
- The percentage of an annotator's submitted work that is approved by review.
- Active Learning
- A machine learning strategy where the model selects the examples it most needs humans to label, reducing the total labeling cost.
- Active Quality Monitoring
- Continuously tracking quality metrics throughout production, rather than only checking at the end.
- Adjudication
- The process of resolving conflicting labels from multiple annotators into a single, final decision.
- Adversarial Examples
- Carefully crafted inputs designed to cause machine learning models to produce incorrect outputs, often through imperceptible modifications.
- Adversarial Prompt
- A prompt crafted to cause an AI model to produce unintended, harmful, or policy-violating outputs.
- Ambiguity Resolution
- The structured process of handling uncertain labeling cases through escalation rather than guessing.
- Annotation
- The process of adding structured labels, tags, or metadata to raw data so that machine learning models can learn from it.
- Annotation Guidelines
- The specification document that defines how human raters should evaluate or label AI outputs for a given training task.
- Attention Mechanism
- A component of neural networks that allows a model to dynamically focus on the most relevant parts of its input when producing each part of its output.
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B
- Bias (in AI)
- Systematic error in AI outputs caused by skewed training data, flawed objectives, or model assumptions that unfairly favor or penalize certain groups or outcomes.
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C
- Calibration
- The process of aligning annotators on a shared interpretation of the guidelines before and during production work.
- Chain of Thought (CoT)
- A prompting technique where a model is instructed to articulate its step-by-step reasoning process before arriving at a final answer.
- Code Correctness Evaluation
- Checking whether generated code actually satisfies the stated requirements and behaves as expected.
- Confidence Scoring
- A rating an annotator provides to indicate how certain they are about their own labeling decision.
- Constitutional AI
- An alignment technique developed by Anthropic in which an AI critiques and revises its own outputs against a set of written principles.
- Content Moderation Labeling
- Classifying content by policy category and severity to support moderation systems.
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D
- Data Augmentation
- Techniques that artificially expand a training dataset by creating modified versions of existing examples to improve model robustness.
- Data Labeling
- The process of adding structured metadata, categories, or ratings to raw data so that AI models can learn from it.
- Data Validation
- Checking labels and metadata against schema and quality rules before a dataset is exported.
- Dataset Versioning
- Tracking schema, label, and policy changes across successive releases of a dataset.
- DPO (Direct Preference Optimization)
- A fine-tuning algorithm that trains a language model directly on human preference pairs, bypassing the need for a separate reward model.
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E
- Edge Case
- A rare but valid sample that stresses the normal labeling rules and often exposes gaps in the guidelines.
- Embedding
- A numerical vector representation of text or other data in a high-dimensional space, where similar items are placed close together.
- Error Analysis
- Clustering failure patterns in labeled or model output data to identify their root causes.
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F
- Fact-Checking for LLM Evaluation
- Verifying whether a model's factual claims are actually supported by trusted context or reference sources.
- Few-Shot Learning
- A model's ability to adapt to a new task from only a small number of examples provided in the prompt, without any parameter updates.
- Fine-Tuning
- The process of continuing to train a pre-trained model on a specific dataset or task to adapt its behavior for a particular use case.
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G
- Generative AI
- AI systems capable of creating new content, including text, code, images, audio, and video, rather than just classifying or predicting existing patterns.
- Gold Set
- A verified benchmark set of pre-labeled items used to audit annotator quality against a known-correct answer.
- Gold Standard
- The most accurate, highly verified data used to train, test, and benchmark an AI model's performance.
- Ground Truth
- The verified correct label or answer against which a machine learning model's predictions are measured during training and evaluation.
- Groundedness
- Whether a model's output is actually supported by the context it was given, rather than invented.
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H
- Hallucination (AI)
- When an AI model generates text that is factually incorrect, fabricated, or inconsistent with reality, while presenting it with confidence.
- Hate Speech Taxonomy
- A defined set of classes and scope rules for labeling abuse targeted at protected groups.
- Human-in-the-Loop (HITL)
- A system design pattern where human judgment is embedded within an automated AI pipeline to guide, correct, or validate model outputs.
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I
- Instruction Following Evaluation
- Checking whether a model's output satisfies the explicit constraints given in the prompt.
- Intent Classification
- Labeling the underlying goal behind a user's text or voice request.
- Inter-Annotator Agreement (IAA)
- A measure of how consistently different human raters assign the same labels or ratings to the same examples.
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J
- Jailbreak Detection
- Identifying prompts specifically crafted to bypass a model's safety constraints.
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L
- Label Noise
- Errors or inconsistencies in a dataset's annotations that reduce model training quality by corrupting the learning signal.
- Large Language Model (LLM)
- A neural network trained on massive text datasets that learns to understand and generate human language across a wide range of tasks.
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M
- Math Reasoning Evaluation
- Checking both the intermediate logical steps and the final numeric answer of a model’s reasoning.
- Misinformation Labeling
- Flagging claims that are unsupported, deceptive, or manipulated.
- Model Alignment
- The research field concerned with ensuring AI systems behave in accordance with human values, intentions, and ethical constraints.
- Multi-Turn Dialogue Annotation
- Labeling conversational quality across turns, including coherence and policy compliance over a whole conversation.
- Multilingual Annotation
- Applying consistent labeling standards for the same task across multiple languages.
- Multimodal AI
- Artificial intelligence systems capable of understanding, processing, and generating multiple types of data such as text, images, and audio.
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N
- Named Entity Recognition (NER)
- Labeling spans of text as people, organizations, locations, or other defined entity types.
- Natural Language Processing (NLP)
- The field of AI focused on enabling computers to understand, interpret, and generate human language.
- Nondeterministic Algorithm (AI / LLM)
- An algorithm that produces different outputs from the same input due to randomness or sampling — why language models give varied answers to identical prompts.
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O
- Overfitting
- When a machine learning model learns the training data too precisely, including its noise, and as a result performs poorly on new, unseen data.
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P
- Pairwise Ranking
- Comparing exactly two candidate outputs and choosing the better one.
- PII Redaction
- Finding and masking personally identifiable information within a dataset.
- Precision and Recall for Labelers
- Precision measures how many of an annotator's positive labels were correct; recall measures how many true positives they actually caught.
- Preference Labeling
- The annotation task of choosing which of two AI outputs is better given a prompt, used to train reward models and alignment systems.
- Preference Ranking
- Comparing two or more model outputs and selecting the better one according to a defined rubric.
- Privacy-Preserving Annotation
- Annotation practices designed to minimize exposure to sensitive data during labeling.
- Prompt Engineering
- The practice of designing, refining, and optimizing input text (prompts) to elicit the most accurate and useful responses from AI models.
- Prompt Injection
- An attack where malicious instructions embedded in user input or retrieved content override an AI system's intended behavior or safety constraints.
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Q
- Quality Assurance (QA) in Annotation Ops
- The combined system of audits, review policies, and feedback loops used to keep annotation quality consistent at scale.
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R
- RAG (Retrieval-Augmented Generation)
- An AI framework that improves the accuracy of model responses by fetching facts from an external knowledge base before generating an answer.
- Red Teaming (AI)
- The practice of systematically probing an AI model to discover harmful, unsafe, or policy-violating outputs before deployment.
- Refusal Quality
- Evaluating whether a model declines an unsafe request clearly, safely, and without being needlessly restrictive.
- Reinforcement Learning
- A machine learning paradigm where an agent learns by taking actions in an environment and receiving rewards or penalties based on the outcomes.
- Response Safety Grading
- Scoring model outputs across defined safety risk dimensions.
- Reviewer Consistency
- Whether QA reviewers apply the same standards uniformly across annotators and over time.
- Reward Model
- A model trained on human preference comparisons that predicts which AI outputs humans consider better.
- RLAIF (Reinforcement Learning from AI Feedback)
- A variant of RLHF where an AI model generates the preference labels used to train the reward model, reducing reliance on human raters.
- RLHF (Reinforcement Learning from Human Feedback)
- A training method where human preference signals are used to fine-tune AI model behavior.
- Root Cause Analysis
- Identifying the underlying source of repeated quality failures, rather than treating each one individually.
- Rubric (AI Training)
- A structured scoring framework that defines what quality means for a specific AI evaluation task, broken into named dimensions with clear criteria.
- Rubric-Based Evaluation
- Scoring outputs across clear, predefined dimensions such as correctness, safety, and completeness.
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S
- Safety Policy Enforcement
- Labeling and evaluating content against a defined set of harm and misuse policy rules.
- SFT (Supervised Fine-Tuning)
- The first stage of instruction-tuning, where a base model is trained on human-written demonstrations of ideal responses.
- Summarization Evaluation
- Scoring a summary for faithfulness to the source, coverage of key points, and clarity.
- Sycophancy (AI)
- An undesirable AI behavior where the model excessively agrees with the user's stated beliefs, opinions, or errors, even when factually incorrect.
- Synthetic Data
- Artificially generated data designed to supplement or replace real-world training data while preserving statistical properties.
- Synthetic Intelligence
- Intelligence produced through deliberate engineering and computation rather than through biological evolution or development.
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T
- Taxonomy and Label Schema
- The defined set of classes and rules used to assign labels consistently across a dataset.
- Temperature (Language Model)
- A parameter that controls the randomness of a language model's output by scaling the probability distribution over possible next tokens.
- Token
- The basic unit of text that language models process, typically corresponding to a word, subword, or character.
- Toxicity Annotation
- Labeling harmful or abusive language patterns in text.
- Transcription Quality
- Measuring accuracy and formatting consistency in speech-to-text labels.
- Transformer (Architecture)
- A neural network architecture that processes sequences using attention mechanisms, enabling parallel training and long-range dependency modeling.
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Z
- Zero-Shot Learning
- A model's ability to perform a task it was not explicitly trained on, using only its pre-trained general knowledge and the task description.
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