Information architecture

Why it matters

People cannot use what they cannot find. Information architecture (IA) is the structure and labelling of content: what goes where, what it is called, and how sections relate. Good IA feels invisible; people click the right menu first time. Poor IA makes people guess, search, give up or call support. It also matters to developers, because the IA becomes routes, menus and page templates.

The core idea: organise by the user's mental model

Teams naturally organise content the way their company is organised ("Billing team pages", "Product team pages"). Users do not know or care about your org chart. They have a mental model: their own idea of what belongs together and what things are called. IA work is about discovering that model and building the structure around it.

IA has three parts:

• Organisation: how items are grouped (by task, topic, audience, time...).
• Labelling: the words used for groups and links.
• Navigation: how people move between them (menus, breadcrumbs, links, search).

Card sorting

A card sort is the classic way to learn users' mental models. You write each content item on a card and ask people to group them.

• Open card sort: participants make their own groups and name them. Use it early to discover how people think.
• Closed card sort: participants sort cards into categories you provide. Use it later to check whether your proposed structure works.

How to run an open card sort:

1. Choose 20 to 40 content items from your product idea. Write each on a card using plain words, not the category name you have in mind.
2. Recruit five or more participants (more improves confidence; 15 or so is common for a real study).
3. Ask each person to put the cards into groups that make sense to them and name each group. Tell them there are no wrong answers and they can make a "not sure" pile.
4. Ask them to think aloud. Note hesitations and cards they move several times.
5. Record every group and its cards.

Paper index cards are perfect. Free tiers of online card-sorting tools exist for remote sorts, but limits change, so check before you rely on one.

Worked example: a house-sharing app

Twelve cards included: Split a bill, Who owes what, Add a housemate, Chore rota, House rules, Bin day reminder, Payment history, Leave the house, Notification settings, Shared shopping list, Move-out checklist, Contact landlord.

Five participants produced groups. A simple table of how often two cards were grouped together (a similarity matrix) showed strong patterns:

Group names participants used most: "Money", "Jobs around the house" and "The house" (or "Our place"). The team had planned a menu called "Finance", "Tasks" and "Admin". The research suggested friendlier labels.

From card sort to sitemap

A sitemap is a diagram of the structure: the top-level sections, what sits under each, and how deep it goes.

Home
├── Money
│   ├── Split a bill
│   ├── Who owes what
│   └── Payment history
├── Jobs
│   ├── Chore rota
│   ├── Bin day reminders
│   └── Shopping list
├── Our house
│   ├── Housemates (add, leave)
│   ├── House rules
│   ├── Contact landlord
│   └── Move-out checklist
└── Settings
    └── Notifications

Good sitemap habits:

• Keep the top level small: about three to seven sections.
• Prefer a broad, shallow structure over a deep one; every extra level is another click and another guess.
• Use the labels participants used, not internal jargon.
• Put an item where most people expected it. If it is split evenly, consider a cross-link from the second place.

Common mistakes

• Organising by org chart. Users do not know your departments.
• Clever labels. "Hub", "Spaces" and "Explore" sound modern but say nothing. Plain words win.
• Cards that give away the answer. If three cards start with "Money:", people will group them by the word, not the meaning.
• Treating card sort results as final. A card sort shows tendencies. Check your sitemap with a tree test (people find items in a text-only version of the structure) before building.
• Too deep. Five levels of menus hides content.

Quick recap

• IA is organisation, labelling and navigation, built around users' mental models.
• Open card sorts discover groups and labels; closed card sorts check a proposed structure.
• Look for strong pairings and common group names, then draft a broad, shallow sitemap.
• Use users' words for labels, and test the structure before building it.

Try it

On the Do tab you will run an open card sort with paper cards and draft a sitemap for your project.