2. UX Task Terminology: Use Cases, Flows, Journeys, and Architecture
Purpose of These Notes
Once you know who you're designing for (Topic 1), you need a shared vocabulary for how they move through your product. These notes explain:
- the difference between use cases, user flows, task flows, and journey maps
- where information architecture fits relative to those flows
- the testing vocabulary (user stories, acceptance criteria, test cases) that turns a flow into something verifiable
You'll use this vocabulary constantly across the rest of the unit — Topic 3 builds your information architecture, and Topic 7 tests the flows you map here.
Most of these terms line up on one axis — zoomed in on the system → zoomed out on the whole experience. Information architecture is the exception: it sits on a different axis entirely (structure, not path). Getting that straight is the whole game.
[!warning] Synonyms masquerading as distinct terms User flow, user flow diagram, and UX flows are essentially the same concept at slightly different framings. Don't teach them as three separate things — teach one concept and note the naming variants. Same trap applies to UX journey, which has no canonical definition.
▶ Watch (overview): What is UX, anyway? — ft. Dr. Jakob Nielsen (NN/g)
Grouped by Altitude
System-spec level
Use case
From software engineering (originally UML / Ivar Jacobson), not design. A structured specification of how an actor (a user, or another system) interacts with your system to achieve a single goal.
Parts of a proper use case:
- Actor — who or what initiates it
- Preconditions — what must be true before it starts
- Main success scenario — numbered steps of the ideal path
- Alternate flows — what happens when things branch or fail
- Postconditions — what's true once it's done
System-centric. Answers "what must the system do so the user can accomplish X?" Covers all paths including failures — which is what makes it useful for building and testing.
▶ Watch: Understanding Use-Cases & User Stories (Geekific) — also nails the use-case vs user-story distinction below.
Interface-path level
User flow
A design artefact showing the concrete path a user takes through your interface to complete a task — screen by screen, click by click — with decision points where the path branches.
Note the diamonds — the branches are what make this a user flow rather than a task flow.
▶ Watch: How to Make a UX User Flow — with an example, 5 min
User flow diagram
The visual artefact of a user flow (the thing rendered above). In practice "user flow" already usually is a diagram, so this term just makes the deliverable explicit — the distinction is thin. Conventions borrowed from flowcharts:
- Rounded / stadium shapes — start and end points
- Rectangles — screens or states
- Diamonds — decision points / branches
- Arrows — direction of travel
Task flow
A single, linear path for one scenario — no branching, one user, one way through. Contrast the diagram below with the branching user flow above.
For testing, your task flows are effectively your test scripts.
UX flows
A loose, non-canonical umbrella term. Usually just means "user flows," sometimes used to bundle user flows + task flows + wireflows together. Treat with suspicion — if a colleague hands you a "UX flow," ask what they actually mean. The ambiguity is in the field, not in your understanding.
Experience level
User journey
Usually a user journey map. Captures the user's whole experience of achieving a goal across time and touchpoints, and adds a layer the flows don't: the user's thoughts, emotions, and pain points at each stage, plus opportunities to improve. Focused on product usage.
The emotion line is the defining feature — here it's the 1–5 satisfaction score per step:
The dips (account creation, waiting) are exactly the pain points a journey map exists to surface.
Customer journey
Broader than a user journey, and from a different tradition (marketing / customer experience). Covers the entire commercial relationship: awareness → consideration → purchase → onboarding → usage → retention → advocacy — including non-product touchpoints like ads, sales calls, billing, and marketing emails.
[!info] User vs Customer — the distinction that matters A user operates the product. A customer is in the commercial relationship. They're often not the same person — think a child using an app a parent paid for, or a B2B tool bought by a manager but used by staff. Roughly: user journey ⊂ customer journey.
▶ Watch: Customer Journey Mapping 101 (NN/g) — the 5 components of a journey map.
UX journey
No canonical definition. Most people use it as a synonym for "user journey"; some mean specifically the experience inside the product. Like "UX flows" — ask before assuming.
The Orthogonal One
Information architecture (IA)
Not a path at all — the structure the paths move through. IA is the organisation, labelling, and navigation of content so users can find things and complete tasks. Its components:
- Organisation schemes — how content is grouped
- Labelling systems — what things are called
- Navigation systems — how users move around
- Search systems — how users query
Deliverables: sitemaps, taxonomies, content inventories, card-sort results, navigation schemes. A sitemap is the classic IA artefact:
The key mental model: flows are routes; IA is the map they're drawn on. You can have a flawless user flow and users still fail, because the IA buried the entry point three menus deep. Bad IA breaks good flows.
▶ Watch: What Is Information Architecture? — UX Design Guide (CareerFoundry)
How They Nest
▶ Watch (how the layers connect): Create User Flow Diagrams From Customer Journey Maps (Headway) — shows the hand-off from journey map down to flow.
Terms for Testing "A Task the User Is Trying to Do"
The terms above describe the landscape. These verify it works.
| Term | What it is | Why it matters for testing |
|---|---|---|
| User story | "As a [role], I want [action] so that [benefit]" | Usually the unit you build and test against |
| Acceptance criteria | Conditions that make a story "done" | Your pass/fail conditions — the single most useful concept for rigorous testing |
| Scenario | Short narrative of a persona reaching a goal in context | Frames usability tests so conditions resemble reality |
| Test case | QA artefact: inputs, steps, expected results | A false friend with "use case" — use case describes intent; test case verifies it |
| Happy path vs edge cases | Ideal run vs boundary/failure conditions | Only testing the happy path is the most common testing failure |
| Task success rate / error rate / time on task | Quantitative usability metrics | Turns "it seemed fine" into a hard number |
| Task analysis (HTA) | Breaking a task into sub-steps | Works out what to test before deciding how |
| Job to be done (JTBD) | The user's underlying motivation | Stops you testing whether a feature works while missing whether it solves the real problem |
Testing IA specifically
Because IA is structural, it needs its own methods that the flow-based ones don't cover:
- Card sorting — users group and label content; reveals how they expect things organised
- Tree testing — users find items in your navigation structure with no visual design; isolates whether the IA itself works
- First-click testing — where users click first to start a task (strong predictor of task success)
The Chain That Matters Most
Write the acceptance criteria well and testing becomes checking each criterion rather than clicking around hoping.
Further Watching — All Links
- What is UX, anyway? — ft. Dr. Jakob Nielsen (NN/g)
- Understanding Use-Cases & User Stories (Geekific)
- How to Make a UX User Flow — with an example, 5 min
- Create User Flow Diagrams From Customer Journey Maps (Headway)
- Customer Journey Mapping 101 (NN/g)
- What Is Information Architecture? — UX Design Guide (CareerFoundry)
Next Steps
You now have a shared vocabulary for tasks, flows, and journeys. In the next topic, Information Architecture & Wireframing, you'll put IA into practice by structuring content and sketching layouts.
End of Topic 2: UX Task Terminology