AoAD2 Practice: Ubiquitous Language

This is an excerpt from The Art of Agile Development, Second Edition. Visit the Second Edition home page for additional excerpts and more!

This excerpt is copyright 2007, 2021 by James Shore and Shane Warden. Although you are welcome to share this link, do not distribute or republish the content without James Shore’s express written permission.

Ubiquitous Language

Audience
Programmers

Our whole team understands one another.

Try describing the business logic in your current system to a domain expert. Can you explain it in terms they understand? Can you avoid programming jargon, such as the names of design patterns, frameworks, or coding styles? Is your domain expert able to identify potential problems in your business logic?

If not, you need a ubiquitous language. It’s a way of unifying the terms your team uses in conversation and code so that everybody can collaborate effectively.

The Domain Expertise Conundrum

One of the challenges of professional software development is that programmers usually aren’t experts in the software’s problem domain. For example, I’ve helped write software that controls factory robots; directs complex financial transactions; analyzes data from scientific instruments; and performs actuarial calculations. When I started working with those teams, I knew nothing about those things.

It’s a conundrum. The people who understand the problem domain—the domain experts—are rarely qualified to write software. The people who are qualified to write software—the programmers—don’t always understand the problem domain.

The challenge is communicating clearly and accurately.

Overcoming this challenge is, fundamentally, an issue of communication. Domain experts communicate their expertise to programmers, who in turn encode that knowledge in software. The challenge is communicating that information clearly and accurately.

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In this Section

  1. Ubiquitous Language
    1. The Domain Expertise Conundrum
    2. Speak the Same Language
    3. How to Create a Ubiquitous Language
    4. Questions
    5. Prerequisites
    6. Indicators
    7. Alternatives and Experiments
    8. Further Reading

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