Improve Communication With Trees, maps, and theorems by Jean-luc Doumont

Trees, models, and theorems.
Cover of “Trees, maps, and theorems” demonstrates the book’s principles. (Used by permission.)

Update: In April 2013, Dr. Jean-luc Doumont is on a speaking tour across California, with a detour to Atlanta. He has free events at many California colleges and will speak at the Society for Technical Communication Annual Conference in Atlanta. See his schedule at the Principiae website.

Highly powered writers I respect have recommended the book Trees, maps, and theorems by Dr. Jean-luc Doumont as a set of coherent recommendations for improving communications, and I am happy to report I can now concur.

As a science/technical writer, I often hope to write the book, the document, the instructions that rescue someone in particular need. Similarly, I often hope that some book or document will save me, have the juju I need to solve a particular writing or presentation problem.

Reading Trees, maps, and theorems, I discovered the book is powerful and does wear a sort of costume: It defines a simple and clear set of communication rules and also puts them into practice while describing how to apply them in a variety of settings. This creates the “costume”: a distinct, consistent and pleasing look and language to every page of the book. That leaves some of us communication professionals muttering about “heroic feats” The book looks like an incredible accomplishment to some who view it, plus it reads well, a task I know can approach the impossible. It leads one to wonder about Doumont in spandex and cape. . .

Trees, maps, and theorems is an admirable model of its own principles, which are captured in three rules that anyone can learn. These rules create a unified approach to all types of communication: oral, written, or graphic.

Doumont’s Three Rules of Communication

  1. Adapt to your audience
    Address them in the manner that best allows them to get your message
  2. Maximize the signal-to-noise ratio
    Reduce distractions of all types; “noise” is anything that interferes with your message (your “signal”)
  3. Use effective redundancy
    Deliver information multiple times, through multiple methods

Examples of Rules

Rule 1: Speaking to children vs. adults; speaking to experts vs. the general public; writing to your boss vs. your favorite co-worker.

Rule 2: Noise includes: saying “um…,” unclear organization, poor sentence structure, unnecessary decorations, choosing the wrong graph type for the data.

Rule 3: Present the agenda throughout a talk; use captions to deliver a true message, not just name the figure; headings, slides, and verbal delivery are mutually reinforcing.

Another important precept from Doumont is to always figure out your purpose — How do you want the audience changed by your message? Without a purpose, there is no point in communicating, so you can just watch re-runs of Buffy the Vampire Slayer.

The book is an admirable example of these principles, with clean, open page layout, two colors, and for each communication medium discussed, applications of the three rules: dependable, consistent practice of Doumont’s own advice. It is full of excellent examples, meaning it can quickly clarify a question of “How can I improve my presentation” (or report or poster or…).

For lay readers, the book’s easy-to-read, consistent instructions and examples provide protection from the darkness of “noisy, inky” reports, presentations, and documents. Doumont’s examples demonstrate how to create high-performing texts and graphics. Doumont’s concepts may not be groundbreaking to many trained communicators, but he does take the ideas further, and is more thorough in their execution than many other educators or proponents.

The book is presented in sections covering fundamentals, written, oral, and graphical communication, and then a section of applying, in different formats, all that has been learned.

Page describing data and graphs.
Graph discussion includes labels, types of graphs, data representation, page layout, and more. (Used by permission.)

Each topic receives its own two-page spread, with the main discussion and examples on the right page while counter-examples and Q&A fall on the left page. This meant I often turned the page and read the “details” on the left page before starting the introductory and main discussion on the outside of the right page. I did read at least one spread in the correct order before the end, but our left-to-right reading direction is so ingrained, I question going against it.

Although Doumont acknowledges others’ work and includes a list of sources and references, there are no citations or web addresses in the body of the text. This follows rule #2 to reduce distractions. Even though I enjoyed reading (and possibly read more effectively) without the boing! of a web address or citation in the text, I missed having more information about related material.

Doumont earned a PhD in applied physics from Stanford. He took technical writing classes and public speaking classes, which eventually he taught. He spent several years moonlighting as a communication design freelancer. This work helped to convince him that he could enjoy the mission for which he was called: saving us all from bad communication! (No spandex required.)

Trees, maps, and theorems is 178 pages and available from You can download sample pages at and learn more about Doumont’s thoughts and rules, or inquire about his attitude toward spandex on his blog at

This post was originally published in August 2012 at It is updated here.

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Kay works with engineers, scientists, and programmers as a writer and editor, which she prefers over working with muggles. When sufficiently caffeinated, she geeks out over words, communication, biology, needlework, and recreational sports. And, of course, chocolate. Her children _may_ have been exposed to D&D at a too-young age, but they continue to play happily to this day.