Technical documentation models

Topic-based documentation

Also known as: Topic-based authoring · Topic-based writing · Modular documentation

Topic-based documentation is a model of technical documentation in which content is written, managed and published as discrete units called topics, each covering one subject and serving one purpose. Topics are assembled into deliverables — manuals, help systems, portals — by maps or navigation structures rather than by the linear flow of a book. The model underlies most current help authoring, component content management and structured publishing systems.

By knowledge.aitechdoc.world · Last reviewed October 1, 2026

Definition

In topic-based documentation, the topic is the basic unit of authoring, reuse and retrieval. A topic answers one question or supports one purpose and can be read without the text that precedes it in any particular deliverable. Topics are combined into publications by a separate structure — a map, table of contents or navigation model — so that the same topic can appear in several publications.

Historical development

The model draws on several strands. Information Mapping, developed by Robert E. Horn from the late 1960s, divided information into small, labeled blocks classified by type. Online help systems of the 1980s and 1990s required content in units that could be displayed independently of a printed sequence. At IBM, these practices were formalized in an XML architecture for typed topics that became the Darwin Information Typing Architecture (DITA), contributed to OASIS in 2004 and approved as a standard in 2005.

Components

Topics. Units with a title, a short description and a body, each limited to one subject.
Information types. Classes of topic with a characteristic structure; DITA distinguishes concept, task and reference topics, with further types such as troubleshooting.
Maps. Structures that select, order and nest topics for a deliverable and carry relationships between them.
Metadata. Properties that identify audience, product, version and other conditions for filtering and retrieval.
Linking. Related-topic links and relationship tables that connect topics outside the hierarchy of a single map.

Function and purpose

Topic-based documentation supports reuse of content across deliverables, parallel authoring by several writers, targeted updates of single units and delivery of individual topics through search and context-sensitive help. It also prepares content for machine processing, because units with a defined type and metadata can be selected and assembled automatically.

Applications

The model is used in software help systems, product documentation for machinery and devices, developer portals and knowledge bases. Delivery standards such as iiRDS describe topics together with metadata, so that content delivery systems can present the right topic for a product, a lifecycle phase or a task.

Limitations

Topics written in isolation can lose the connections that a reader needs. Collections of small units without adequate context, navigation or linking are sometimes described as fragmented. Topic size is not defined by the model; very small topics increase management effort, while very large ones reduce the benefits of reuse.

Relation to other models

Topic-based documentation provides the unit; other models specify what the unit should contain. Task-based documentation determines which topics are needed, Every Page is Page One sets requirements for how each topic stands on its own, and structured authoring enforces the structure of each information type.

Conclusion

Topic-based documentation replaced the book as the primary unit of technical content. Its value depends on clear information types, maps and links that restore the context removed by modularization.

Cite this article

knowledge.aitechdoc.world. “Topic-based documentation.” Encyclopedia, AI TechDoc Blog. Last reviewed October 1, 2026. https://knowledge.aitechdoc.world/encyclopedia/technical-documentation-models/topic-based-documentation

Context cards

Glossary terms

Topic (technical communication): In technical communication, a topic is a self-contained unit of content that covers a single subject and serves a single purpose, written so that it makes sense without the content that precedes or follows it. Topics are the units that authors write, review, approve, translate, reuse, and assemble into deliverables such as manuals, help systems, and content delivery portals. The general concept is not fixed by a single standard: structured formats such as DITA and iiRDS each define their own topic constructs, and in-house information models define topic types of their own. What the implementations share is the pairing of one title with one subject and one communicative purpose.
DITA (Darwin Information Typing Architecture): DITA (Darwin Information Typing Architecture) is an OASIS XML standard for creating, managing and publishing topic-based content. Content is authored as typed topics, organized and reused through maps, and extended through specialization. DITA 1.3 is the version approved by OASIS in December 2015.
DITA topic: In DITA, a topic is a unit of information with a title and content that is short enough to be specific to a single subject and can be understood on its own. The generic topic type, <topic>, is the base from which all other DITA topic types are specialized.
DITA concept: In DITA, a concept is a topic type for conceptual information: it answers “what is” questions and gives the background a reader needs to understand a product, process or idea. Its body element is <conbody>.
DITA task: In DITA, a task is a topic type for procedural information: it describes how to accomplish a goal, usually as a sequence of steps. Its body element <taskbody> contains sections such as prerequisites, context, steps, result and follow-up, and each step contains exactly one command.
DITA reference: In DITA, a reference is a topic type for information that readers look up rather than read from start to finish, such as specifications, parameters or command syntax. Its body element <refbody> is organized in sections, tables and property lists.
DITA troubleshooting topic: In DITA 1.3, a troubleshooting topic is a topic type for problem-solving information: it describes a condition (the symptom a reader observes), one or more possible causes and, for each cause, a remedy. Its body element is <troublebody>.
DITA information typing: In DITA, information typing is the practice of writing each topic as one type of information — such as a concept, a task or a reference — with a content model designed for that type. The information type determines which elements a topic may contain and in what order.
DITA map: In DITA, a map is a document that organizes topics and other resources into a structured collection — typically a deliverable such as a manual or help system. It defines the hierarchy and sequence of topics, their relationships and key definitions, and can contain other maps.
DITA relationship table: In DITA, a relationship table (<reltable>) is a map element that defines links between topics in the form of a table: topics in different cells of the same row are related, and processors generate links between them in the output.
Metadata: In information management, metadata is data that describes other data or resources, such as their meaning, origin, format, units, owner, time stamp, version or classification, so that they can be found, understood, managed and used correctly.
iiRDS Topic: In iiRDS (intelligent information Request and Delivery Standard), a Topic is an information unit that deals with a single subject and can be understood on its own — for example one task, one concept or one reference table.