Reference
Glossary
Technical definitions of the terms we use when we talk about causal AI, agents and observability.
Causality
Causal AI
AI that works out what causes what, not only what tends to go together.
Methods that use or learn a causal model of a system to answer interventional and counterfactual questions, not only to predict from association.
Causal discovery
Finding the causal graph from the data.
Algorithms that search data for graph structure consistent with it, under assumptions such as causal sufficiency and faithfulness. Domain knowledge, such as the order of events in time, fixes what the data alone cannot settle.
Causal graph (DAG)
A map of what influences what.
A directed acyclic graph where nodes are variables and directed edges represent direct causal influence.
Causal inference
Working out what actually caused an outcome, not just what came with it.
Estimating causal effects from data under explicit assumptions, typically encoded in a causal graph or structural model.
Causation vs correlation
Two things happening together is not proof that one caused the other.
Correlation is statistical association. Causation means intervening on one variable changes the distribution of the other.
Collider
A shared result of two causes. Filtering on it can create false connections.
A variable with two incoming edges on a path. Conditioning on it opens the path and can induce spurious association.
Confounder
A hidden common cause that makes two things look connected.
A variable that causally affects both the treatment and the outcome, creating a non-causal association between them.
Counterfactual
What would have happened in this exact case if one thing had been different.
A query about a specific unit or event under a hypothetical intervention, holding its background conditions fixed.
Effect estimation
Measuring how strongly one thing affects another.
Quantifying the causal effect of a treatment on an outcome, for example as an average treatment effect, under the identification assumptions of the causal model.
Identifiability
Whether the data we have is enough to answer the causal question.
Whether a causal quantity can be uniquely computed from the observed data distribution under the stated assumptions.
Intervention
Deliberately changing one thing to see what happens.
Setting a variable to a fixed value, written do(X = x), which removes the influence of its usual causes.
Ladder of causation
Three levels of question: what happened together, what happens if we change something, and what would have happened otherwise.
Pearl's hierarchy of association, intervention and counterfactual queries. Each rung requires stronger assumptions than the one below.
Mediator
A step in between, through which one thing affects another.
A variable on a causal path X → M → Y that transmits part of X's effect on Y.
Observational vs interventional data
Data from watching the system vs data from changing it on purpose.
Observational data is collected without manipulation. Interventional data comes from controlled changes such as experiments or replays.
Refutation test
A check that tries to break a causal result.
A robustness test of an estimated effect, for example adding a placebo cause or a random common cause, to see whether the estimate changes when it should not.
Root cause
The main reason something went wrong.
Often implies a single cause. In agent systems outcomes usually have several contributing factors.
Spurious correlation
A link between two things that is not a cause.
An association that does not come from a causal path between the variables, for example one created by a confounder.
Structural causal model (SCM)
A model of how each part of a system is produced by its causes.
A set of structural equations, one per variable, defining it as a function of its direct causes and an independent noise term. Supports interventional and counterfactual queries.
Methods and tools
DAGMA
A discovery method that learns the graph by optimization.
A continuous-optimization approach to structure learning that enforces acyclicity with a log-determinant constraint.
DoWhy
An open-source toolkit for causal analysis.
An open-source Python library that structures a causal analysis as four steps: model, identify, estimate and refute. Auga's causal engine uses it for effect sizes.
EconML
An open-source toolkit for estimating how much a change affects an outcome, using machine learning.
An open-source Python library of estimators for heterogeneous treatment effects, such as double machine learning and causal forests. Auga's causal engine uses it for effect sizes.
FCI
A discovery method that allows for hidden common causes.
Fast Causal Inference: an extension of the PC algorithm that tolerates latent confounders and selection bias. It returns a partial ancestral graph rather than a DAG.
LiNGAM
A discovery method that uses the shape of the noise in the data to tell which way an arrow points.
Linear Non-Gaussian Acyclic Model: it assumes linear relations and non-Gaussian noise, which makes edge directions identifiable from observational data.
PC algorithm
A classic discovery method that finds a causal graph by testing which variables are independent of each other.
A constraint-based causal discovery algorithm. It removes edges using conditional independence tests, then orients the rest from collider structures and orientation rules. It assumes no unmeasured common causes.
PCMCI+
A discovery method for data that changes over time.
A causal discovery algorithm for time series. It combines a PC-style selection of conditions with momentary conditional independence tests, and also finds links within the same time step.
Transfer entropy
A measure of how much one time series helps predict another, beyond what the second one's own past already does.
An information-theoretic measure of directed information flow between time series. It shows predictive flow, not by itself a causal effect.
AI and agents
Agent
An AI system that takes steps on its own to reach a goal.
A system where an LLM selects actions, such as tool calls, in a loop, based on a goal, its context and the results of earlier actions.
Context
Everything the agent can see when it makes a decision.
The input to the model at a given step: instructions, conversation history, retrieved documents and tool results.
Groundedness
Whether an answer comes from the documents the AI was given.
The degree to which a model's output is supported by the retrieved context it was given, as opposed to being fabricated.
Guardrail
A rule that stops the agent from doing something it should not.
A check applied to inputs, outputs or actions that blocks, modifies or escalates them based on a policy.
Hallucination
When the AI states something that is not true or not supported.
Output not supported by the model's context or by fact.
Intent and outcome
What the agent was supposed to do, and what actually happened.
The task goal as specified to the agent, and the final observed result of execution.
LLM (large language model)
The AI model that reads and writes text.
A neural network trained to predict tokens, used as the reasoning and generation component of an agent.
LLM judge
An AI model that grades another AI's answers.
A model prompted to score outputs against a criterion, such as hallucination or groundedness. It is an evaluation method with its own error rate.
MCP (Model Context Protocol)
A standard way for AI agents to connect to tools and data.
An open protocol for connecting LLM applications to external tools and data sources. In Auga's architecture, MCP clients are external agents that use the API.
Multi-agent system
Several AI agents working together, each with its own role.
A system of agents that exchange messages or shared state to complete a task. Failures can propagate between agents.
Prompt and completion
What the model was asked, and what it answered.
The input given to a model and the output it returned for one call.
Retrieval (RAG)
Looking up documents and giving them to the agent before it answers.
Retrieval-augmented generation. Relevant content is fetched from an external source and inserted into the model's context.
Tool call
When the agent uses an outside tool, like a database lookup or an API.
A structured function invocation emitted by the model, executed by the runtime, with the result returned to the model's context.
Observability and evidence
Evaluation (eval)
Testing how well an AI system does its job.
Systematic measurement of model or agent output against criteria, datasets or reference answers.
Observability
Being able to see what happened inside a system.
The ability to understand a system's internal state from its external outputs, mainly telemetry.
Observation, inference, hypothesis
What we saw, what we concluded from it, and what we think might be true but have not tested.
Observation is recorded evidence. Inference is a conclusion derived from evidence under a model. Hypothesis is a candidate explanation awaiting testing.
OpenTelemetry (OTel)
An open standard for recording what software does.
A vendor-neutral standard and toolkit for generating and exporting traces, metrics and logs. Auga uses OpenTelemetry traces as input.
PII (personally identifiable information)
Information that can identify a person.
Data such as a name, an email address or an ID number that identifies a person directly or in combination with other data. Regulations such as the GDPR restrict how it may be processed.
Span
One step in that record.
A timed unit of work within a trace, with attributes, events and a parent relationship.
Telemetry
The data a system records about what it is doing.
Logs, metrics and traces emitted by a running system.
Trace
The full record of one run, step by step.
A tree of spans describing one end-to-end execution, such as a single agent task.
Auga terms
Causal engineReview needed
The part of Auga that finds the causal graph.
The service that reads the extracted variables from the database, runs discovery and estimation algorithms, and grades every edge before it is trusted.
Causal observability
Seeing not only what an AI agent did, but why.
Observability extended with causal modeling, so that traces can answer interventional and counterfactual questions, not only descriptive ones.
Extracted variableReview needed
A measurable value Auga pulls out of a trace, such as how long a step took.
A typed value derived from trace data under an allowlisted schema. It is used as a node in the causal graph.
Human readinessReview needed
What people on the receiving end of an automated system are owed: to reach a human, get an explanation, contest a decision and more.
The ten criteria Auga uses to tag laws by what they ask for people affected by automated decisions.
LensReview needed
A part of the Auga application built to answer one question, such as cost or the EU AI Act.
A view of the application organized around one question. The current lenses cover the EU AI Act, the Oversight Inbox, cost, operations and agent health.
Governance
Audit trail
A record that lets someone check afterwards what the system did and why.
Tamper-evident, time-ordered records of system actions and decisions, sufficient to reconstruct and review them.
EU AI Act
The European Union's law on AI. It sets rules according to how risky an AI system is.
Regulation (EU) 2024/1689. It sets obligations by risk category and applies in phases.
Explainability vs interpretability
Explaining a decision in terms people understand, vs understanding how a model works inside.
Explainability gives human-understandable reasons for specific outputs. Interpretability concerns the internal mechanisms of a model. Auga works mainly at the system level: explaining agent behavior from evidence, not model internals.
High-risk AI system
An AI system used where mistakes can seriously affect people, as defined in the EU AI Act.
A category under the EU AI Act subject to requirements on risk management, record-keeping, transparency and human oversight.
Human oversight
People being able to monitor, understand and step in.
Measures that let humans supervise an AI system, interpret its output and intervene or stop it, as required for high-risk systems.
Traceability
Being able to follow a decision back to where it came from.
The ability to link an output to its inputs, intermediate steps and responsible components.