By the end of this lesson you can
- Explain what information architecture is and why it matters.
- Compare common organisation schemes such as alphabetical, task-based and audience-based.
- Choose an organisation scheme based on how users think, not how the organisation is structured.
The idea
Information architecture (IA) is the structure of a product: how content and features are organised, labelled and connected so people can find what they need and understand where they are.
Organisation schemes
There are only a few basic ways to group things:
- Exact schemes: alphabetical, chronological, geographical. Useful when people know exactly what they are looking for (a name, a date, a place).
- Topic: grouping by subject, such as "Mortgages" and "Savings".
- Task: grouping by what people want to do, such as "Pay a bill" and "Report a problem".
- Audience: grouping by who people are, such as "Students" and "Staff". Useful only when audiences need clearly different content and people know which group they belong to.
Most products mix schemes: a top level by task, then alphabetical lists inside.
Users' mental models, not the org chart
The most common IA failure is mirroring the organisation's internal structure. Visitors to a council website do not know which department handles parking permits; they just want a parking permit. Good IA follows users' mental models: the way they already think about the subject.
Why it matters in real projects
If people cannot find something, it may as well not exist. Poor IA increases support calls, makes features look missing and erodes trust. Because IA sits underneath every screen, mistakes are expensive to fix later. Getting the structure right early makes navigation, search and content design much easier.
A realistic example
A university website is organised by faculty and department. Prospective students looking for "accommodation" find it under "Estates and Facilities", a department name nobody outside the university recognises.
The team reorganises the top level by task for its main audience: "Study with us", "Fees and funding", "Accommodation", "Student life". Department pages still exist, but they are no longer the way in. Search logs show "accommodation" searches fall by half, because people now find it in the navigation.
Step by step
List the content
Collect the main content and features the product needs to hold.
Learn how users think
Look at search logs, support questions and research to find users' words and groupings.
Try two or three schemes
Sketch the same content organised by topic, task and audience.
Check against real tasks
For five common tasks, ask where a user would look in each version.
Pick and refine
Choose the scheme that serves the most common tasks, then test it (see card sorting and tree testing).
Common mistakes
Mistake Copying the organisation chart.
Instead Organise around user tasks and language.
Mistake Audience-based navigation where audiences overlap.
Instead Only split by audience if people can confidently pick one group.
Mistake Designing IA alone at a desk.
Instead Use research and testing to check structure with real users.
Check your understanding
Choose an answer, then check it. There is an explanation either way.
Practice exercise
Exercise · about 40 min
Three schemes, one site
Take a local library's website content (events, borrowing, digital resources, opening times, membership, venues for hire) and organise it three ways.
Steps
- List at least 20 content items.
- Organise them by topic, by task and by audience.
- Test each version against five common tasks.
- Choose one and explain why.
Deliverable
Three draft structures and a short rationale.
Self-assessment
Tick each item when it is true of your exercise. Be honest; this is for you.
4 items
Summary
- IA is the structure that helps people find and understand content.
- Common schemes are exact, topic, task and audience.
- Follow users' mental models, not internal structures.
- Test structures against real tasks.
Further reading
Third-party sources, chosen for reliability. They open in a new tab.
- The difference between information architecture and navigation (opens in a new tab)Nielsen Norman Group
- Mental models (opens in a new tab)Nielsen Norman Group
Your notes
Marking complete updates your course and roadmap progress.