lAItest / AI field guide · edition 2026-09-26
Know the language. Build with clarity.
Plain-English definitions for the concepts, patterns, protocols, and tools behind modern AI work.
414 defined terms · 16 topic areas · 50 essentials
Models, reasoning & training terms
36 matching terms.
- Inference-time compute Concept · Models, reasoning & training
Computation spent solving a request rather than training the model.
- LoRA Concept · Models, reasoning & training
Low-rank adaptation: learn low-rank parameter updates instead of updating all model weights.
- SFT Concept · Models, reasoning & training
Supervised fine-tuning: train on examples of desired inputs and outputs.
- Active parameters Concept · Models, reasoning & training
The subset of model parameters used for a given token or computation path.
- Attention Concept · Models, reasoning & training
A learned mechanism for combining information from different input positions or representations.
- Base model Concept · Models, reasoning & training
A pretrained model before a particular instruction or preference adaptation stage.
- Best-of-N Pattern · Models, reasoning & training
Generate multiple candidates and select one using a scoring method.
- Chain of thought Concept · Models, reasoning & training
Intermediate reasoning expressed in steps; visible explanations are not guaranteed faithful traces of internal computation.
- Constitutional AI Concept · Models, reasoning & training
An alignment approach using explicit principles to guide critique and AI-derived feedback.
- Dense model Concept · Models, reasoning & training
A model whose main parameters are generally used for each token, unlike sparse expert activation.
- Distillation Concept · Models, reasoning & training
Train a student model using supervision obtained from a teacher model or system.
- DPO Concept · Models, reasoning & training
Direct Preference Optimization: train on preference pairs without a conventional separate online RL optimization stage.
- Fine-tuning Concept · Models, reasoning & training
Adapting pretrained model weights with task, domain, or preference data; supervised fine-tuning and parameter-efficient methods are distinct approaches.
- GRPO Concept · Models, reasoning & training
Group Relative Policy Optimization: estimate relative advantages from groups of sampled responses for policy optimization.
- Instruction-tuned model Concept · Models, reasoning & training
A model trained on examples of responding to instructions.
- Logits Concept · Models, reasoning & training
Unnormalized model scores over candidate outputs, often transformed into probabilities.
- Mixture of experts Concept · Models, reasoning & training
A model architecture routing computation through a subset of expert components.
- Open weights Concept · Models, reasoning & training
Model weights are accessible under a license; training data and unrestricted usage rights are not implied.
- PEFT Concept · Models, reasoning & training
Parameter-efficient fine-tuning: adapt a model by training a limited subset or added parameters.
- Post-training Concept · Models, reasoning & training
Training after pretraining to improve instruction following, preferences, specialized behavior, or reasoning.
- PPO Concept · Models, reasoning & training
Proximal Policy Optimization: a policy-gradient reinforcement-learning method using constrained updates.
- Pretraining Concept · Models, reasoning & training
Broad training that establishes a model's initial representations and capabilities.
- QLoRA Concept · Models, reasoning & training
Parameter-efficient adaptation using low-rank updates with a quantized base model.
- Reward model Concept · Models, reasoning & training
A model that estimates preference or quality for training, evaluation, or candidate selection.
- RLAIF Concept · Models, reasoning & training
Reinforcement learning using feedback generated by AI systems.
- RLHF Concept · Models, reasoning & training
Reinforcement learning using reward signals derived from human feedback.
- RLVR Concept · Models, reasoning & training
Reinforcement learning with verifiable rewards, such as outcomes checked by tests or objective graders.
- Self-consistency Pattern · Models, reasoning & training
Aggregate results from multiple sampled reasoning attempts, often by answer agreement.
- SLM Concept · Models, reasoning & training
Small language model: a relative size label with no single universal parameter threshold.
- Synthetic data Concept · Models, reasoning & training
Generated examples used for training, evaluation, or augmentation.
- System 1 / System 2 Concept · Models, reasoning & training
Informal metaphors for fast direct responses and deliberative processing, not standard model architectures.
- Temperature Concept · Models, reasoning & training
A sampling parameter that reshapes relative token probabilities; its effect depends on the decoding setup.
- Tokenization Concept · Models, reasoning & training
Convert input into units from a model-specific vocabulary.
- Top-p Concept · Models, reasoning & training
Nucleus sampling: select from a probability-ranked token set meeting a cumulative probability threshold.
- Total parameters Concept · Models, reasoning & training
The full parameter count of a model, including components not active on every token.
- Transformer Concept · Models, reasoning & training
A neural architecture built around attention and learned transformations of token representations.
Browse by topic
- Agents & architecture 23 — Who decides, what executes, and where control lives.
- Goals, specs & plans 23 — Describe the outcome before delegating the implementation.
- Loops, critics & adversaries 33 — Understand how work is challenged, repaired, and stopped.
- Multi-agent coordination 21 — Delegation, ownership, context boundaries, and aggregation.
- Context & memory 29 — What the model sees now, and what persists for later.
- Tools & output contracts 20 — Model proposals become validated, authorized operations.
- Protocols & interoperability 19 — Name the boundary: tools, agents, editors, or interfaces.
- Coding-agent internals 25 — Instructions, skills, hooks, tools, and durable artifacts.
- Retrieval & knowledge 31 — Find evidence, rank it, and preserve source boundaries.
- Evals & observability 29 — Measure outcomes and inspect the execution path.
- Inference & performance 28 — Latency, throughput, compute, and memory are different constraints.
- Models, reasoning & training 36 — Separate weight changes from context and inference-time work.
- Security & reliability 27 — Make privileges explicit and side effects recoverable.
- Generative UI & voice 18 — The interaction layer has its own contracts and timing.
- Generative & physical AI 8 — Broader model families beyond text-based assistants.
- Tools & ecosystem 44 — Recognize the role before choosing the dependency.