Adaptive Switches and Switch Access in Accessibility Testing


When using a computer, most users use the standard keyboard and mouse interface. Similarly, when using a phone, they use their fingers to operate the touch screen. However, what if users cannot use computers and mobile devices in such a way? What if they suffer from some kind of temporary, permanent, or situational disability that prevents them from using a device in an ‘expected’ way?

Millions of people around the world with varying degrees of disability use assistive technologies. Unfortunately, few people know about the concept of assistive technology and how important it is to ensure equal access to technology for users with disabilities. With about 1.3 billion people, or 16% of the world's population, suffering from a severe disability, it is now more important than ever to focus on accessibility and assistive technology.

While there are various types of assistive technologies, like screen readers, magnifiers, and speech-to-text software, in this blog post we will be focusing on switches. We will explain what a switch is, describe the different types of switches, and provide examples of how they can be used in accessibility testing.

What is a switch?

A switch, or adaptive switch, is an assistive technology device that allows people with physical disabilities to activate assistive technology devices based on their needs, preferences, or dexterity. Hence, the name adaptive. How you use adaptive switches, the response of the switch, and the type of support provided are all factors to consider when choosing an adaptive switch. An adaptive switch has two states—on and off.

Who uses switches?

Hand pressing down on an adaptive switch

Switches are used by people with disabilities who cannot access a keyboard, touch screen, or any type of pointer control. They are suitable for people with physical, intellectual, or cognitive disabilities, as they provide an easy way to access and control electronic devices.

Different types of adaptive switches

Adaptive switches are input-output devices that come in all different shapes and sizes, and work differently. Often switches operate with a pushing motion, but there are also switches that require you to grasp, pull, puff, or even blink to activate. But the most common type of switch is the buddy button or the jelly bean switch. All switches perform the same action so the only variation is in the force needed or technique used to activate it. This is why different adaptive switches are used by people with different needs. Let’s look at some different types of adaptive switches and their use.

Sound switch

A sound-activated switch uses voice control or other identifiable sound—like an utterance or clap—to allow people with motor disabilities to operate the switch.

Body switch

A body switch allows people with limited movements to access gadgets with the slightest movement of their fingers or some other part of the body. A joystick is one example of a body switch that users can move in different directions to control a variety of devices, like phones, tablets, TVs or other gadgets that support Bluetooth.

Plate switch

Plate switches, which are shaped like plates, are used by people with motor disabilities, like injuries in the fingers, who cannot use small switches. They have a large surface, are lightweight and specially designed to respond to even the slightest touch. In order to use it, users need to run their hand (or foot) over the surface and press several times to activate it.

Saucer switch

A saucer switch is suitable for people with limited mobility. These switches are specifically designed for people who cannot control or maintain the hand or wrist movements required to operate traditional plate switches. The saucer switch is activated with a light touch. The pressure adjustable poppet switch allows users to adjust pressure based on ability and has a small LED light that glows when the switch is activated.

Pillow switch

The soft surface of the pillow switch provides physical feedback as well as an audible click when pressed. With its smooth and soft foam surface, this switch is suitable for head or cheek activation. Shoulders, arms and hands can also be used to trigger the switch. It easily attaches to a pillow or wheelchair cushion with a safety pin and Velcro.

Grasp switch

A grasp switch is a tube-shaped switch that users hold in the palm of their hands. It can be activated with a squeeze or a pinch. The user must be able to release the grip after approximately two seconds to prevent intermittent operation of the switch. It can be mounted on a range of surfaces.

How are adaptive switches beneficial?

Adaptive switches are designed to provide a good experience for people with reduced mobility or disabilities. As a result, they encourage inclusivity and ensure users have equal access to various electronic devices and are able to control them independently.

Adaptive switches significantly improve the quality of life by reducing the chance of injury to people (in terms of the use of various electrical devices), reducing the amount of time needed to perform simple tasks, as well as allowing people with disabilities to be more self-sufficient in general and independent in the use of devices.

Another advantage is that different switches are capable of activating speech generating devices. In today's world, voice commands help users in places where voice commands are required. For example, when using voice search or general control of devices such as electronic gadgets, wheelchairs, and televisions.

Switch access and mobile devices—What is switch access?

Switch access is a special way to operate a smartphone, tablet, computer, and a variety of other electronic devices by using one or more switches. It replaces the use of more complex interfaces that most people use every day, such as keyboards and touch screens.

Switch access allows users with physical or cognitive impairments to use their mobile devices without touching the screen. Namely, a helper feature called switch access is built into mobile operating systems. Switch access is an auxiliary function available on both iOS and Android operating systems. The switch access function on devices requires the use of any of the switch devices described above or the function inside the device can be configured as a switch.

Switch access scanning

Switches are most commonly used as an indirect access method called switch access scan. A switch access scanning system shows the user a set of parameters and automatically scans them cyclically, highlighting each one individually.

Unlike direct selection (such as touching the screen), the scanner can only make a selection when the scanning indicator of the electronic device is on the desired selection. The scan indicator moves over the items, highlighting each item on the screen, and then the user activates the switch to select the item. For example, if the user wants to write a message, the system will scan the keyboard key by key, one by one, and when the desired key is highlighted, the user must press the switch to insert the desired character. And so, the process of writing a message is repeated until complete.

The speed and pattern of the scan, as well as the way items are selected, is customized based on the ability of the user.

Scanning patterns

A scan pattern is how the items in a selection set are presented to the user. This clearly simplifies item selection, as the scan is systematic and predictable. Let's look at three basic scan patterns:

Circular scanning

In circular scanning, the individual elements are arranged in a circle (like the numbers on a clock face), and the scan indicator moves around and scans one element at a time. This type of scan pattern is the easiest to master from a cognitive point of view.

Line scanning

In line scanning, elements are usually laid out in a grid, and the scan indicator moves systematically over each element in each line. Such scanning is relatively simple and easy to learn, but it can sometimes be inefficient. For example, if there are many elements in the set, as in a grid of 10 elements per row, and the desired element is the 8th element in the fifth row, the scan indicator would have to look at 48 unwanted elements.

Group scanning

With this kind of scanning, the elements are grouped, for example, by rows/columns/other meaningful categories. The scan indicator first scans in groups and once the scanner selects the group that the desired item belongs to, the scan indicator will scan each item in the selected group.

Scanning control techniques

The selection of elements is carried out by activating the switch in three main ways:

Directional scanning

The indicator scans according to the specified pattern only when the user holds the switch. In this case, the selection of an element on the screen will be carried out only when the switch is released.

Automatic scanning

The indicator automatically scans the given template, and the element is selected when the user presses the switch.

Step by step scanning

The user controls each step of the scan indicator for a given pattern by pressing a switch.

Using switches during accessibility testing

Desktop computer, laptop, and different types of adaptive switches pictured on desk

The use of switches is important when performing accessibility testing, as it ensures that the various criteria described in WCAG are met. Since the switch works specifically by focusing on elements on the screen and their interaction, this affects several important scenarios during the testing process. Here are some WCAG 2.1 success criteria that can be met with switches:

1.3.1 Information and Relationships

When working with this recommendation, content styling should be considered in order to convey information and relationships in a way that will be logically presented to the user. Let's look at some examples.

For programmatic focus to be logical, you need to make sure that appropriate table markup is used, and row and column headings are marked up so as to establish information and relationships between cells.

Similarly, when grouping information you must provide grouping and group level labels to mark a group of form elements, such as radio buttons or checkboxes. In this case, the <fieldset> and <legend> tags can be used to achieve grouping, or you can use ARIA to achieve the same results when using custom form controls.

2.4.3 Focus Order

This recommendation assumes sequential navigation which means that interactive elements should receive focus in a predictable, natural reading order—in most cases, left-to-right and top-to-bottom sequence.

One way to avoid focus order issues is to make sure that elements appear on screen in the same order they appear in the document object model (on the web), or view hierarchy if using an iOS or Android device.

One example of correct focusing would be the following situation. When a button click brings up a modal dialog box, the focus should move to the open window and stay inside it until the user closes that window. One of the biggest problems in this situation occurs if the focus stays behind the dialog box instead of moving to the elements of the open modal.

3.2.1 On Focus

In the context of this recommendation, the purpose of the success criterion is that when any component receives focus, it does not initiate a context change. This ensures that no unwanted actions are triggered when focus is moved to the element.

One example would be when links don't open a new page or new window when focusing on them, the action should only be triggered when the link is clicked.

Another common example can be seen in the initiation of content during tab navigation. Let's say you have an online store web page open with a navigation bar on the left that shows 3 categories, for example, "men", "women" and "children". When the user's focus is on one of them, a new tab with products of that category opens automatically, even though the user did not select any of the categories by clicking on them.

Final thoughts

The use of adaptive switches in the testing process is important for compliance with accessibility standards, like WCAG, as it is an additional guarantee of equal access to technologies for people with disabilities. Under the condition of qualitative testing of accessibility, the overall quality of the user experience also increases.

Every day, more and more people resort to modern solutions and new equipment. For people with disabilities, adaptive equipment is one of the best options to help them adapt their lives to the modern world. Adaptive switches are a great option for people with limited motor skills or coordination to manage devices needed for daily use, allowing a person to take more control of their lives and have equal access to technology.

Want to check how accessible your software product or application is? Contact us to find out more about our accessibility testing services and how we can help you build software products that are inclusive, meet various accessibility standards, and are compatible with various assistive technologies—including adaptive switches.

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