H3 triangle. Three horizontal layers: The Conduct at apex, led by Heart; The Structure in the middle, led by Head; The Model at base, led by Hand

The triangle has three layers. At the base, The Model: the practitioner’s relationship to the work itself. Craft, execution, the direct contact between a designer and the thing being made. Hand carries the most weight here, because the Model is where you learn to make things well, with precision and intent.

In the middle, The Structure: the practitioner’s relationship to their career. The levels, the paths, the decisions about where to go and how to get there. Head carries the most weight here, because building a path means reading the field you work in: position, consequence, and trajectory. A designer who can read the field they are operating in and make considered choices about it has a developed Structure.

At the top, The Conduct: the practitioner’s relationship to other people: leadership, influence, building teams and culture. Heart carries the most weight here, because leading people starts with understanding them accurately: who they are, what they need, and what serving them well requires. Conduct is where a designer’s relationship to other people becomes the primary demand of the work.

A layer, then, is a relationship: to the work, to the path, to the people. Each becomes the main demand of the job at a different stage of a career, which is why the book also reads the layers as stages (1.7) and uses them as the columns of the Phase × Layer Map (2.4). Hand, Head, and Heart are not divided among the layers. All three run through every layer, and Part One, the Model, has a chapter on each. What changes from layer to layer is which one carries the most weight. Each H also keeps one meaning throughout: Hand is making the thing at the standard, Head is understanding the system around the work, and Heart is understanding the people the work is for, accurately enough to serve them (1.4). When the book applies an H to a leadership domain or a team value, it means the same capacity at a larger scale.

The ordering of Hand, Head, and Heart (and of Model, Structure, Conduct) follows the practitioner’s accountability: first to the work, then to the path, then to the people. That sequence describes how the layers typically develop. You build craft before you navigate a career. You navigate a career before you lead other people through theirs.

But development sequence is not operation sequence. At any given moment, all three layers are active. A senior designer presenting work operates Model (the craft on screen), Structure (navigating the room and the stakes), and Conduct (reading the people) simultaneously.

Which dimension is most developed in you right now? Which is most neglected? Which one is holding everything else back? That is the question H3 is built to answer.

The Trianglethree layers, and the mode that leads each