Every Page is Page One

Definition

An EPPO topic is a self-contained page that serves one specific purpose for a qualified reader and connects to other pages by links. The model concerns the design of the individual page and of the network of pages, rather than the hierarchy of a publication. It is a model of writing, not a markup standard, and can be implemented with any authoring or publishing technology.

Historical development

Baker developed the model in the context of online documentation and information foraging, the behavior of readers who search, scan and follow links until they find what they need. The book contrasted EPPO topics with fragments produced by modularizing book content and with collections of topics that rely on a table of contents for their meaning. Baker later extended the argument to structured writing in Structured Writing: Rhetoric and Process (XML Press, 2018).

Components

Baker names seven characteristics of an EPPO topic:

1. Self-contained. The topic can be understood without reading another page first.
2. Specific and limited purpose. The topic serves one purpose for its reader.
3. Conforms to a type. The topic follows the pattern of its kind of content, which makes it predictable for readers and writers.
4. Establishes its context. The topic states where it belongs — product, situation, audience — instead of relying on its position in a book.
5. Assumes the reader is qualified. The topic is written for the reader who can use it and links to prerequisites rather than repeating them.
6. Stays on one level. The topic does not mix overview and detail.
7. Links richly. The topic links to related topics along the relations a reader may follow.

Function and purpose

EPPO aligns documentation with the way information is found on the web. Pages that establish their own context and link along meaningful relations form a bottom-up information architecture: navigation emerges from the links between pages rather than from a single imposed hierarchy.

Applications

EPPO principles are applied in developer documentation, knowledge bases and product documentation published on the web. The EPPO Projects on this site apply them to fictional documentation for integrated machinery lines, where each page names its line, stations, lifecycle phase, audience and page type.

Limitations

EPPO topics do not replace documents that must be read as a whole, such as instructions for use that a product is supplied with or contractual documents. Rich linking requires maintenance, and the model gives no formal mechanism for enforcing its characteristics; enforcement depends on templates, structured authoring or editorial review.

Relation to other models

EPPO refines topic-based documentation by setting requirements for each topic’s independence and context. It shares the user focus of task-based documentation but is not limited to tasks. Semantic documentation and structured authoring can make EPPO characteristics machine-checkable, for example by requiring context metadata on every page.

Conclusion

Every Page is Page One redefines the topic as a reader’s entry point rather than a fragment of a book. Its characteristics provide criteria for evaluating whether a page can stand on its own.