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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 systemzoomed 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.

TermWhat it isWhy it matters for testing
User story"As a [role], I want [action] so that [benefit]"Usually the unit you build and test against
Acceptance criteriaConditions that make a story "done"Your pass/fail conditions — the single most useful concept for rigorous testing
ScenarioShort narrative of a persona reaching a goal in contextFrames usability tests so conditions resemble reality
Test caseQA artefact: inputs, steps, expected resultsA false friend with "use case" — use case describes intent; test case verifies it
Happy path vs edge casesIdeal run vs boundary/failure conditionsOnly testing the happy path is the most common testing failure
Task success rate / error rate / time on taskQuantitative usability metricsTurns "it seemed fine" into a hard number
Task analysis (HTA)Breaking a task into sub-stepsWorks out what to test before deciding how
Job to be done (JTBD)The user's underlying motivationStops 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.


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