Self-service terminals is a term to cover all kinds of Devices in public spaces with which a visitor interacts. In this article, we also use the shorter term "kiosk", although that doesn't always cover it.
Accessibility of self-service terminals goes beyond accessible websites and apps. Those are used via a familiar computer, tablet or smartphone that is customized to personal needs via accessibility settings or assistive technologies. Self-service terminals, on the other hand, are a closed environment: the devices must offer various interaction methods. Moreover, the user has no prior knowledge of how they work.
We begin with some examples of self-service terminals and then provide recommendations for designers and developers of accessible self-service terminals: environmental factors, the accessibility of the device itself and providing a customizable user interface. We conclude with practical applications and refer to the European standard.
Even if you take all the tips in this article to heart, it is still important to provide an alternative. Make sure that people can always contact an employee who can help or take over the operation.
Examples of self-service terminals
There are many devices in public spaces that we use to perform a variety of tasks:
- look up information via an information kiosk in a museum or tourism center,
- consult passages or look up routes via the information kiosk in a train station or bus stop,
- withdraw money from an ATM,
- pay in a store using a payment terminal,
- register for the queue in a post office or town hall,
- sign up for a hospital appointment,
- use the self check-in in a hotel or at the airport,
- cast your vote on election day through a voting machine,
- buy a drink or coffee from a vending machine,
- buy a ticket from a parking meter or from a ticket vending machine at the train station,
- use the self-scanning checkout and fruit scales in the supermarket,
- pick up a parcel from an automatic parcel machine,
- place an order in a takeaway restaurant,
- return books at the library ...
These activities can only be accessible experiences when the devices are physically accessible and provide multiple operating methods.
- Is a blind or visually impaired person informed that a self-service terminal is present: is the device sufficiently visually prominent? Does a tactile guide line lead you to the device?
- Can everyone physically get to the device? Make sure the route from the entrance is free of obstacles and sufficiently wide. Provide sufficient space around the device to maneuver a wheelchair.
- Pay attention to lighting: if the device is outside, shield it from sunlight; if it is inside, provide appropriate lighting: sufficiently strong, well directed and not blinding.
- Provide the ability to sit while waiting your turn and while using the device.
A self-service terminal is an unfamiliar device to the user: they have no prior knowledge of what the device looks like, what functions it offers and how it works.
- The physical layout of the device must be very simple and predictable. It should also be immediately clear what you can do with the device.
- In the physical design of the device, you need to pay attention to the height of screen and controls, as well as suitability for driving under. Is the device usable by large, small and seated users?
- If physical actions are required (inserting a card, taking out a ticket ...) it can be done with 1 hand and requires minimal grip, strength and wrist rotation.
- A self-service terminal is only accessible if the device itself offers all sorts of different operating methods: if it has a screen, you will want to have that information read to blind people. Take this into account in the physical design of the device and build in a speaker and/or jack for headphones. If there isn't one, you can't develop a voice interface. Consider its physical location. Position the speaker for optimal intelligibility and discretion. Place the headphone jack in a logical location that you can easily identify.
- If the terminal has a motion detection function, then also keep in mind the unpredictable movement patterns of people with e.g. developmental coordination disorder.
- Provide disinfectant gel.
Most users are new and unfamiliar with the device and its operation.
- Keep the user interface simple and uncluttered. Provide no more buttons than necessary, make them large and label them clearly.
- Always make it clear how to go back or undo an action.
- Consider the multiple sense principle. Can someone who can't see or hear operate the device? The device itself must provide that. You cannot use the usual assistive technologies that a blind or deaf user is used to on their own device.
- If the device has physical buttons: are they clearly labeled in Braille and large contrast letters?
- If the device has a screen: choose a readable and high-contrast font and possibly offer a function to enlarge text. For blind people, you will need to provide an alternative. Speech output is the most obvious.
- If the device has a touch screen:
- Make the click areas sufficiently large and do not place them too close together.
- Calibrate well so that one does not have to press unnecessarily hard or does not accidentally activate something at the slightest touch,
- For blind people, provide an alternative such as physical buttons or a control concept as found in screen readers for smartphones and tablets with a touchscreen.
- If the device produces sound: provide the ability to adjust the volume.
- Most Web Content Accessibility Guidelines also apply here:
- provide ample time for all actions,
- avoid moving and flashing elements,
- caption videos
- Touch-screen voting machines and ATMs have provided an audio variant: if the user plugs in headphones, the screen shuts off for privacy and spoken instructions take over. Operation is via physical buttons that are also still present on the device.
- Also enable control of the device via an app. The user can then perform all actions on their familiar, accessible device. The app then instructs the device to print a ticket or open the right door of the parcel delivery machine, for example.
- Some banks allow you to withdraw cash from an ATM through the app. App and ATM exchange data via a QR code and the money comes out of the slot. If the bank's app is then easily accessible, this allows you to indirectly work independently with an inaccessible device.
- The JAWS screen reader is best known in a Windows environment. There is a variant to make information kiosks accessible. video
Because a self-service terminal is a closed environment, the Web Content Accessibility Guidelines are not sufficient. We therefore refer to the European standard EN 301549. Version 3.2.1 can be downloaded for free from ETSI's website. Be sure to read these chapters:
- Clause 5.1 Closed functionality because you cannot connect your own assistive technology to a self-service terminal. It describes what functionalities the device must provide.
- Clause 8.3 Stationary ICT provides information on hardware accessibility such as heights and underrideability.
- Clause 8.4 Mechanically operable parts has info on what a keyboard should look like, and how much strength may be needed to remove something from a machine....
- Clause 11 Software has a section on what is expected for "closed functionality" for almost every WCAG criterion.