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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.
ai careers quality and qa
Active Learning
A machine learning strategy where the model selects the examples it most needs humans to label, reducing the total labeling cost.
training methods ml fundamentals
Active Quality Monitoring
Continuously tracking quality metrics throughout production, rather than only checking at the end.
quality and qa
Adjudication
The process of resolving conflicting labels from multiple annotators into a single, final decision.
quality and qa
Adversarial Examples
Carefully crafted inputs designed to cause machine learning models to produce incorrect outputs, often through imperceptible modifications.
safety and alignment ml fundamentals
Adversarial Prompt
A prompt crafted to cause an AI model to produce unintended, harmful, or policy-violating outputs.
safety and alignment annotation
Ambiguity Resolution
The structured process of handling uncertain labeling cases through escalation rather than guessing.
quality and qa
Annotation
The process of adding structured labels, tags, or metadata to raw data so that machine learning models can learn from it.
annotation ai careers
Annotation Guidelines
The specification document that defines how human raters should evaluate or label AI outputs for a given training task.
annotation
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.
core concepts ml fundamentals

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.
safety and alignment ml fundamentals
Bounding Box Annotation
Drawing rectangular boxes around target objects in images.
annotation

C

Calibration
The process of aligning annotators on a shared interpretation of the guidelines before and during production work.
quality and qa
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.
training methods annotation
Class Imbalance
A dataset condition where some labels appear far more often than others.
data
Code Correctness Evaluation
Checking whether generated code actually satisfies the stated requirements and behaves as expected.
evaluation
Confidence Scoring
A rating an annotator provides to indicate how certain they are about their own labeling decision.
data quality and qa
Constitutional AI
An alignment technique developed by Anthropic in which an AI critiques and revises its own outputs against a set of written principles.
safety and alignment training methods
Content Moderation Labeling
Classifying content by policy category and severity to support moderation systems.
safety and alignment annotation

D

Data Augmentation
Techniques that artificially expand a training dataset by creating modified versions of existing examples to improve model robustness.
data ml fundamentals
Data Labeling
The process of adding structured metadata, categories, or ratings to raw data so that AI models can learn from it.
annotation ai careers
Data Validation
Checking labels and metadata against schema and quality rules before a dataset is exported.
data
Dataset Versioning
Tracking schema, label, and policy changes across successive releases of a dataset.
data
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.
training methods

E

Edge Case
A rare but valid sample that stresses the normal labeling rules and often exposes gaps in the guidelines.
quality and qa
Embedding
A numerical vector representation of text or other data in a high-dimensional space, where similar items are placed close together.
core concepts ml fundamentals
Error Analysis
Clustering failure patterns in labeled or model output data to identify their root causes.
data quality and qa

F

Fact-Checking for LLM Evaluation
Verifying whether a model's factual claims are actually supported by trusted context or reference sources.
core concepts evaluation
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.
training methods core concepts
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.
training methods

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.
core concepts
Gold Set
A verified benchmark set of pre-labeled items used to audit annotator quality against a known-correct answer.
quality and qa
Gold Standard
The most accurate, highly verified data used to train, test, and benchmark an AI model's performance.
annotation ml fundamentals
Ground Truth
The verified correct label or answer against which a machine learning model's predictions are measured during training and evaluation.
annotation ml fundamentals
Groundedness
Whether a model's output is actually supported by the context it was given, rather than invented.
core concepts evaluation

H

Hallucination (AI)
When an AI model generates text that is factually incorrect, fabricated, or inconsistent with reality, while presenting it with confidence.
safety and alignment core concepts
Hate Speech Taxonomy
A defined set of classes and scope rules for labeling abuse targeted at protected groups.
safety and alignment
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.
ai careers ml fundamentals

I

Instruction Following Evaluation
Checking whether a model's output satisfies the explicit constraints given in the prompt.
evaluation
Intent Classification
Labeling the underlying goal behind a user's text or voice request.
annotation
Inter-Annotator Agreement (IAA)
A measure of how consistently different human raters assign the same labels or ratings to the same examples.
annotation

J

Jailbreak Detection
Identifying prompts specifically crafted to bypass a model's safety constraints.
safety and alignment

L

Label Noise
Errors or inconsistencies in a dataset's annotations that reduce model training quality by corrupting the learning signal.
annotation ml fundamentals
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.
core concepts

M

Math Reasoning Evaluation
Checking both the intermediate logical steps and the final numeric answer of a model’s reasoning.
evaluation
Misinformation Labeling
Flagging claims that are unsupported, deceptive, or manipulated.
safety and alignment annotation
Model Alignment
The research field concerned with ensuring AI systems behave in accordance with human values, intentions, and ethical constraints.
safety and alignment
Multi-Turn Dialogue Annotation
Labeling conversational quality across turns, including coherence and policy compliance over a whole conversation.
evaluation
Multilingual Annotation
Applying consistent labeling standards for the same task across multiple languages.
annotation
Multimodal AI
Artificial intelligence systems capable of understanding, processing, and generating multiple types of data such as text, images, and audio.
core concepts data

N

Named Entity Recognition (NER)
Labeling spans of text as people, organizations, locations, or other defined entity types.
annotation
Natural Language Processing (NLP)
The field of AI focused on enabling computers to understand, interpret, and generate human language.
core concepts ml fundamentals
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.
ml fundamentals core concepts

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.
ml fundamentals

P

Pairwise Ranking
Comparing exactly two candidate outputs and choosing the better one.
training methods evaluation
PII Redaction
Finding and masking personally identifiable information within a dataset.
safety and alignment annotation
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.
data quality and qa
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.
annotation ai careers
Preference Ranking
Comparing two or more model outputs and selecting the better one according to a defined rubric.
training methods evaluation
Privacy-Preserving Annotation
Annotation practices designed to minimize exposure to sensitive data during labeling.
safety and alignment annotation
Prompt Engineering
The practice of designing, refining, and optimizing input text (prompts) to elicit the most accurate and useful responses from AI models.
core concepts ai careers annotation
Prompt Injection
An attack where malicious instructions embedded in user input or retrieved content override an AI system's intended behavior or safety constraints.
safety and alignment

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.
ai careers quality and qa

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.
training methods core concepts
Red Teaming (AI)
The practice of systematically probing an AI model to discover harmful, unsafe, or policy-violating outputs before deployment.
safety and alignment
Refusal Quality
Evaluating whether a model declines an unsafe request clearly, safely, and without being needlessly restrictive.
safety and alignment evaluation
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.
training methods ml fundamentals
Response Safety Grading
Scoring model outputs across defined safety risk dimensions.
safety and alignment evaluation
Reviewer Consistency
Whether QA reviewers apply the same standards uniformly across annotators and over time.
ai careers quality and qa
Reward Model
A model trained on human preference comparisons that predicts which AI outputs humans consider better.
training methods
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.
training methods
RLHF (Reinforcement Learning from Human Feedback)
A training method where human preference signals are used to fine-tune AI model behavior.
training methods core concepts
Root Cause Analysis
Identifying the underlying source of repeated quality failures, rather than treating each one individually.
data quality and qa
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.
annotation ai careers
Rubric-Based Evaluation
Scoring outputs across clear, predefined dimensions such as correctness, safety, and completeness.
core concepts evaluation

S

Safety Policy Enforcement
Labeling and evaluating content against a defined set of harm and misuse policy rules.
safety and alignment annotation
SFT (Supervised Fine-Tuning)
The first stage of instruction-tuning, where a base model is trained on human-written demonstrations of ideal responses.
training methods
Summarization Evaluation
Scoring a summary for faithfulness to the source, coverage of key points, and clarity.
evaluation
Sycophancy (AI)
An undesirable AI behavior where the model excessively agrees with the user's stated beliefs, opinions, or errors, even when factually incorrect.
safety and alignment annotation
Synthetic Data
Artificially generated data designed to supplement or replace real-world training data while preserving statistical properties.
data training methods
Synthetic Intelligence
Intelligence produced through deliberate engineering and computation rather than through biological evolution or development.
core concepts

T

Taxonomy and Label Schema
The defined set of classes and rules used to assign labels consistently across a dataset.
annotation core concepts
Temperature (Language Model)
A parameter that controls the randomness of a language model's output by scaling the probability distribution over possible next tokens.
ml fundamentals
Token
The basic unit of text that language models process, typically corresponding to a word, subword, or character.
core concepts ml fundamentals
Toxicity Annotation
Labeling harmful or abusive language patterns in text.
safety and alignment annotation
Transcription Quality
Measuring accuracy and formatting consistency in speech-to-text labels.
annotation
Transformer (Architecture)
A neural network architecture that processes sequences using attention mechanisms, enabling parallel training and long-range dependency modeling.
core concepts ml fundamentals

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.
training methods core concepts

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