From evidence to action

The Search Discovery Stack

A twelve-layer operating model for following information from creation through customer or agent action.

Published 2026-07-22Last reviewed 2026-07-22Primary-source analysis
Layers 1–3

Create, publish and discover

Creation

A person or system produces a fact, claim, image, record, policy or description. Provenance and ownership begin here.

Publication

The material becomes available through a page, profile, feed, API, file or database. Visibility depends on access conditions.

Discovery

Crawlers, links, submissions, sitemaps and connected datasets expose the material to systems that may process it.

Layers 4–6

Index, recognize and retrieve

Indexing

A service processes material into a search index, vector store, knowledge base or other searchable representation.

Recognition

Names, identifiers, relationships and context are used to determine which real-world entity the material describes.

Retrieval

The system selects documents, passages, fields or records relevant to the request. Poor retrieval can exclude the best source before generation starts.

Layers 7–9

Generate, attribute and present

Generation

A model turns instructions and context into language, comparisons, recommendations or actions.

Attribution

The product may attach links or citations, but the citation may support only part of the generated statement.

Presentation

Interface rules determine order, prominence, number of choices, visual treatment and whether the user continues to a source.

Layers 10–12

Evaluate, select and act

Reliability

Freshness, source quality, retrieval quality and generation fidelity determine whether the answer is useful and accurate.

Selection

The user or agent chooses among the visible options. Omitted alternatives may never be considered.

Action

The journey produces a call, visit, booking, purchase, subscription, tool execution or no action at all.

Where the disciplines fit

The stack is larger than any one acronym

SEO is strongest in publication, crawling, indexing, relevance and presentation. REG concentrates on recognition and retrievable facts. AEO structures direct answers. GEO considers usefulness in generated responses. RAG is an architecture inside retrieval and generation. Reliability frameworks such as NIST span governance, measurement and risk across the entire system.

The stack makes those relationships visible without pretending that the boundaries are perfectly rigid.

Diagnostic worksheet

Questions for every layer

Source trail

Primary material behind this analysis

Related reading

Continue through the discovery stack

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