Unit 3 · Lesson 11 of 20
Design the full state sequence
Specify what patients and staff see as check-in moves from entry to receipt or delay.
01 / Learn
Learn the method
Fictional case
The team has chosen a receipt-backed kiosk message and needs to specify its behavior across the whole task.
Terms for this lesson
- State
- The condition the interaction or service has reached.
- Transition
- An event that moves the service between states.
- Source of truth
- The record or event that supports a displayed claim.
A state describes the service at one moment. A transition is the event that moves it to another state. For check-in, the sequence begins ready for entry, moves through code entered and sending, then reaches receipt confirmed or a delayed response. A separate reset returns the shared kiosk to its starting view.
For each state, write the event that created it, what the kiosk can truthfully display, what Mira can do, and what staff can see. The service receipt is the source for a confirmed arrival. A sending state communicates progress during a wait. A delayed state offers a safe route for status checking and help.
States also cover correction. An unmatched code can return Mira to entry with her useful input preserved. An appointment mismatch can show the detail that needs review and a reception route. After completion, the kiosk clears personal information for the next person. Each branch supports the same overall goal.
A state table makes implementation and testing precise. Designers, engineers, and reception staff can compare the words on screen with the events in the appointment service. Test the messages with patients who arrive under realistic time pressure.
Use the method
- List the states from entry through receipt, delay, correction, and reset.
- Give each transition a trigger and each message a source of truth.
- Specify the patient's action and staff route in every consequential state.
A complete interaction includes transitions, recovery, and a privacy reset alongside the success screen.
- Nielsen Norman Group: 10 Usability Heuristics for User Interface Design ↗System status, error prevention, and recovery as checks rather than recipes.
- Nielsen Norman Group: Error-Message Guidelines ↗Make failure visible, understandable, and recoverable.
- GOV.UK Service Manual: Writing for user interfaces ↗Put the important action and state in plain, concise language.
02 / See the reasoning
Worked example
The team lists the trigger 'service receipt received.' The kiosk then shows 'The clinic has received your check-in' and a waiting instruction. The staff queue may still refresh later, so reception uses the receipt lookup when Mira asks. The team also specifies a delayed state with a status-check route. Engineering can now connect each message to a defined event.
Try a decision →03 / Decide
Guided decision
The appointment service has accepted the request, and reception's queue still shows an older view. Which kiosk state matches the known event?
Feedback on your choice
What could change the answer: A clinic policy that defines staff queue visibility as the formal check-in point would call for a distinct intermediate receipt state.
Use this feedback to examine your choice and written reasoning.
Build your case file →04 / Build the case
Your case file
Fictional case update
A request takes longer than the usual sending interval, and the kiosk retains Mira's entered code.
Evidence and constraints
- Fictional service detail: a receipt identifies an accepted arrival request.
- Fictional system detail: the kiosk retains an entered code during a temporary request delay.
- Fictional operations detail: reception can query a receipt directly; its queue refreshes separately.
Add a delayed state and a recovery branch to the state table. Write the message, available action, and staff lookup behavior.
Create: A state table for ready, entered, sending, received, delayed, correction, and reset.
Every displayed claim has a trigger, a source of truth, an available action, and a next state.
- The receipt event controls the received message.
- The delayed path preserves a useful route to resolution.
- The shared screen returns to a privacy-safe starting state.
The state table defines the behavior a prototype must represent.
Lesson complete
You added to your case file.
You studied the method, practiced a decision, and added an artifact to your case file. Carry that reasoning into the next lesson.
05 / Keep working