Mapping the Gap
Mental model mismatch exercise
"I pulled the session logs from last week's kiosk observations. Out of fifteen riders, eleven tapped 'Zone Map' expecting to see ticket prices. The designers put pricing under 'Fares.' Eleven out of fifteen never found it."
"So riders think the zone map and the pricing are the same thing?"
Sable pulled out a blank page and drew two columns. On the left she wrote "Designer's Model." On the right, "Rider's Model." She hadn't even started filling them in and already the columns felt like they belonged to different systems entirely.
"What I keep seeing in the transcripts is riders saying 'I must have done something wrong.' They blame themselves. But if eleven out of fifteen make the same mistake, what does that tell us about who's actually wrong?"
"The system is wrong. The designers organized the kiosk the way they think about transit — zones, fares, schedules as separate categories. But riders just want to get somewhere. They're not thinking in categories at all."
She added a third column between the other two and labeled it "The Gap." Every item in this column would be a place where someone got stuck — a mismatch between what the designer built and what the rider expected.
"The designer's intended structure — the conceptual model — assumes riders think in categories. But their mental models are task-based: 'I need to get to the airport.' They don't care whether that's a zone question or a fare question."
"I just realized something. I've been riding the subway since I was twelve, and I always thought the Blue and Green lines ran parallel. They actually cross twice. My mental model of the whole network was wrong for over a decade."
"And during those years — did you ever get lost because of it?"
"Once, at the junction. I took the Green platform thinking it went north, but it curves east there. The map in my head and the map on the wall were showing me different cities."
Sable's diagram — designer's model vs. rider's model — is a way of making the gap between a conceptual model and a mental model visible. When the gap is wide, riders fail. When it's narrow, the system feels intuitive.
The principle that visible information is easier to use than information that must be recalled from memory. Designs that favor recognition present options, labels, and cues at the moment of decision — so users can see and choose rather than remember and retrieve.
- Recognition relies on seeing — a labeled button, a visible menu, an icon that matches a known action
- Recall relies on remembering — a keyboard shortcut, a blank search box, a code you were told once
- Reducing recall is one of the most reliable ways to lower cognitive load across any interface
In the studio: Rider 7's kiosk experience was pure recall — twelve unlabeled-looking buttons with no clear path to a single ticket. A redesign that showed "Buy a Single Ticket" as a visible option on the first screen would shift the interaction from recall to recognition.
The studio elevator had floor buttons arranged in two columns — but the left column controlled odd floors and the right column controlled even floors. Sable pressed the right button for floor 3, and the doors opened on floor 4.
The spatial arrangement of the buttons implied a mapping that didn't match reality — the same kind of mismatch Rafa described with the stovetop's four knobs in a row.
A delivery driver pulled up to a Meridian station parking area and looked for the loading zone. He drove past it twice — the sign said "Commercial Access" in small grey text on a grey wall. His mental model of a loading zone was a painted curb and a large yellow sign.
The driver's mental model was built from every other loading zone he'd ever used. When the Meridian station broke that pattern, his expectations made the real sign invisible.
Sable opened a file-sharing app on her phone expecting folder categories like her laptop. Instead the app showed every file sorted by date — most recent first. She scrolled past forty files looking for a project brief she'd saved two weeks ago.
The app designer's conceptual model organized files by recency. Sable's mental model organized them by project. The mismatch turned a simple task into a long scroll.