( Process )
Seven layers, and the bottleneck is almost never the last one
Seven layers in three zones, and they are not phases. Each rests on the ones below it, so a weak layer never stays where it is: it travels upward and arrives as a complaint about the screen. The frame is for diagnosis. Enter anywhere, then check what is underneath.
A weakness anywhere in the section arrives at the top of it. That is why the surface is where the complaint lands and almost never where the fault is.
( Problem space )
What is true. Gathered, not decided, and wrong only in the sense of being incomplete.
01
Observed behaviour
What do people actually do, as opposed to what they say?
Field work, and the discipline to rate a finding by how much I actually saw rather than by how well it lands in a deck. The spreadsheet somebody keeps beside the software is always here somewhere, and it is the most honest document in the building.
Artefact: Findings, each carrying its own confidence rating
02
Domain
What world is this, and what do the words in it mean?
The vocabulary, and the places it disagrees with itself. Two teams using one word for two things is the most expensive bug on a project and the last one anybody thinks to look for.
Artefact: A glossary with the conflicts marked, not resolved
03
User needs
Which of those behaviours point at something worth fixing?
Not every friction is an opportunity and not every complaint is a need. This layer is mostly about throwing things away, and being able to say why.
Artefact: A prioritised set of opportunities
( Solution space )
What we choose. Every layer here is a decision somebody made, which means every one of them can be wrong.
04
Product strategy
Which needs do we take, and what are we betting?
The join between what people want and what the business gets. A bet has a stated assumption and a cheap way to test it, or it is not a bet, it is a plan.
Artefact: Named bets, each with its riskiest assumption
05
Conceptual model
What objects exist, what states do they have, what are they called?
Decided before any screen exists and independent of every one of them. The most load-bearing layer here and the most often skipped, because it is the only one that produces nothing anybody can look at.
Artefact: Objects, relationships, states, and one agreed name each
06
Interaction flow
What are the places, and how do people move between them?
Structure without visual form. Places, affordances, edge cases, and the unglamorous failure paths that decide whether a tool survives its second week.
Artefact: Flow maps including every path that fails
07
Surface
Does what you can see agree with everything underneath?
The layer everyone means when they say design. It is last not because it matters least, but because almost every surface problem I have been called in to fix turned out to be a symptom of one of the six above.
Artefact: The thing you can actually click
The seven layers, their order and the zones are mine. The shape of the idea, design as layers that depend on the ones beneath them, is Jesse James Garrett's, from The Elements of User Experience, 2000.
( Next )
Show me the screen everyone is blaming
Almost every surface I have been called in to fix turned out to be a symptom of something three layers under it. Finding which one is the first thing I do.