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PTN·03·004

The Wizard

Steps as mercy documented

A wizard is one task wearing several screens. It buys a smaller decision at each moment and pays for it in page loads, and whether that trade is mercy or obstruction depends almost entirely on who is on the other side. For someone doing this once — registering a company, claiming a benefit, opening an account — the long single page is a wall, and the wizard is the thing that makes the task appear finishable. For someone doing it weekly, the same wizard is eleven interruptions where there could have been one.

The strongest version of the pattern is GOV.UK's, and its strength is that it is stated as a rule rather than a layout: one thing per page. Ask a single question, validate it there, move on. The rule survives contact with the awkward cases — it forces the designer to decide what a "thing" is, and that decision is usually where the difficulty of the task was hiding.

The pattern's characteristic failure is not division but concealment. A wizard that does not show how many steps remain has not made the task shorter; it has made its length unknowable, which is worse than a tall page. The honest wizard tells you where you are, lets you go back without losing anything, and — because a long task will be interrupted by a phone call — lets you come back tomorrow and find it where you left it.

one page length visible, progress not one thing per page step 2 of 4 — and back does not lose it fewer decisions per screen, paid for in page loads — mercy for the once, tax for the weekly
FIG 03·004 — the same task, cut two ways.
AnatomyA single task cut into ordered steps, one screen each · a visible position in the sequence · forward and back that both preserve what has been entered · validation at the step, not at the end · a final review before the irreversible act · and — the part most often missing — a resumable state, because a long task will be interrupted.

Use when

  • The task is genuinely long and genuinely ordered — later answers depend on earlier ones
  • The alternative is one page so tall that a person cannot see whether they are close to finishing
  • Each step can validate itself, so an error is caught next to the field that caused it
  • The task is unfamiliar and infrequent: applying for something, not filing something weekly

Avoid when

  • The user is an expert repeating the task — a wizard turns a two-minute form into eleven page loads
  • The steps are not really ordered, and the sequence is the designer's filing system rather than the task's shape
  • Steps cannot be revisited without loss, which converts a mercy into a trap
  • The wizard exists to hide the length of the task rather than to divide it — the total must stay visible
States & accessEach step is a page, or is announced as one: focus moves to the new step's heading, and the step count is in the accessible name rather than only in a progress graphic. Back must be the browser's back as well as the interface's. The ARIA Authoring Practices publish no wizard pattern — this is a composition of headings, forms and landmarks, which is a feature: it means the accessible version is the ordinary one.
HistoryNamed for the installer wizards of early-1990s desktop software (Microsoft's Publisher and Setup wizards popularised the term), and rehabilitated for the web by public services, where the tasks are long, the users are one-time, and the failure is expensive.
SpecimensGOV.UK service journeys · tax filing · bank onboarding · passport and visa applications · multi-step checkout.
Principle at stakeHick–Hyman and progressive disclosure — fewer decisions per screen — held against the cost of the page loads that buys.
SourcesGOV.UK Service Manual, one thing per page, and the GOV.UK Design System question-page pattern, both published with the research behind them; Microsoft's wizard guidance in the Windows interface guidelines for the origin of the term.
See alsoFloor 4 will judge these as flows — by their worst step, which for most wizards is the one asking for an address.

Why documented: GOV.UK publishes <i>one thing per page</i> as a pattern together with the user research and iteration behind it, on a service used by an entire population. That is a named, findable primary source, which is the bar this building sets.