A little while ago, whilst studying for my post-grad, I came across the book “Assistive Technology: Principles and Applications for Communication” By Oliver Wendt. It’s quite a heavy going book, but Chapter 4, ‘Universal Principles and Guidelines’, struck a chord with me. At this time Assistive Technology (AT) wasn’t overly prevalent in the UK, with many Specialist Colleges or Schools not having dedicated roles to support this aspect of disability learning support. I was involved in delivering an early Jisc funded project ran by Beaumont College called DART (Disseminating Assistive Roles and Technology) which aimed at rectifying this situation through a series of deep-support interventions and workshop.

The idea of some common guidelines appealed to me as a method to provide a consistent language for what we were trying to achieve, to explain the world of AT .

However, the text is arduous and not an easy resource to share (the book costs £100! — luckily the Chapter I’m discussing here is available on Google Books to preview, should you wish) so I set about creating a simplified handout as an attempt to support the dissemination of AT.

The result is this PDF, which you can download here.


This blog post is intended to expand a little more on that handout, to explain some of the principles in detail.

I believe the whole purpose of Assistive Technology is to minimise effort; enabling someone to achieve a task, through the least effortful way possible — be it a reduction in cognitive or physical means. Sometimes, technology provides the method to make that task a little simpler, a little more efficient or effective, depending on the users needs and abilities. We live in a world where we all use hardware and software solutions to minimise effort (predictive text, washing machines etc.) and AT is a field that expands this concept further to the unique barriers that people with disabilities face.

Principle 1 — The Principle of Parsimony

“Parsimony: Adoption of the simplest assumption in the formulation of a theory or in the interpretation of data, especially in accordance with the rule of Ockham’s razor”

Or more eloquently…

“Everything should be made as simple as possible, but no simpler”

Unfortunately, Parsimony has a 2nd definition of ‘stingyness’, but that’s not what I’m advocating here.

Essentially this principle, is about being effective and efficient, both in approach to a solution and in the end-users use of any equipment. It’s very easy to create a complex solution that also creates barriers for users — especially those with learning difficulties. Learning how to design solutions and approaches simply is common theme throughout these principles.

One of the best solutions I’ve seen recently is from a local Headteacher who created a table of square cells in Word to enable a keyboard user to complete maths problems. Easily navigable, free, and simple to replicate (download my version of her simple Word template here) allowing the pupil to show her workings like every other child in the class.


Principle 2— The Principle of Minimal Learning

“Don’t make me think”

Whilst I was queuing to wash my hands at Leeds train station, there was a vast amount of signs instructing people how to use their new complex taps. Now, I’ve washed my hands many many times before, as have (I hope) my fellow passengers, yet somehow, someone had thought it necessary to install these bizarre taps, with identical looking bizarre soap dispensers. The result…

Water and soap everywhere, a long queue of frustrated commuters and likely, many unwashed hands (ugh). All down to poor design which required additional thinking.

I’ve recently enjoyed Black Box Thinking by Matthew Syed, in which he cites a case in the 1940s where B-17 bomber pilots were mistaking the flaps and landing gear controls as they were identical and similarly placed. The solution in future designs: “attaching a rubber wheel to the landing-gear switch and a small flap shape to the flaps control. The buttons now had an intuitive meaning” — A little bit of thought and good design reduces cognitive load.

Intuitive controls, reducing cognitive load

We need to take the same approach with AT. The people we work with are often physically tired, and thinking can be hard. By adding further load through poor design in any AT solutions, we creating unnecessary barriers to success.

One of the reasons I created ACCESS: YouTube was the mainstream YouTube site was a distracting mess (it’s not much better now). Users needed to think about where to type and what to click on. ACCESS: YouTube automatically puts the focus on the search box and has no irrelevant elements on the page, minimising cognitive load allowing users to crack on and watch their Littlemix videos.

Principle 3— The Principle of Minimal Energy

“The required physical effort must be lower than the motivation to complete a task”

This is the physical counterpart to the cognitive based Principle 2. Here is all about positioning and working with the Physio and OT is paramount.

I’ve come to realise that the implementation of AT is a 3 step process:

  • 1-Positioning
  • 2-Access
  • 3-Control

Quite simply, stop everything until the user is comfortable. After a recent Cerebral Palsy training session with a Physiotherapist, we’ve adopted a ‘calibration’ approach to interventions where positioning the user correctly, and ensuring their body is relaxed and controlled, enables them to have the greatest chance of success using their equipment.

If the seating is wrong, then focus on solving that first. Constantly trying to hold their body to control their AT is an unnecessary waste of energy and one that might be avoidable. We’re also usually desiring the user to access their AT for extended periods of time, so being comfortable is an absolute must.

Once positioning is correct and they are comfortable, then you can look at how they are going to actually access their tech. Constant experimentation over time is key, as whilst you may have success with a headswitch, or joystick, it might be less effortful to use a switch by the knee or an eyegaze solution.

Only once positioning and access is established (and regularly reflected upon, as bodies grow and change) then start to look at the control of their AT.

Principle 4— The Principle of Minimal Interference

“Users must be enabled to maintain focus on completing the task at hand”

Here is a reminder that the actual use of the solution can be distracting, removing focus for what is trying to be achieved. One of our clients gets a huge amount of pleasure from the tactile nature of a keyboard, and finds pressing all the keys quite enjoyable! As a result, he is constantly distracted whilst trying to type his school work, and so is unable to complete any. Our solution has been to use a touchscreen keyboard for him, ensuring his screen is angled to be comfortable for long periods of typing.

This approach is also incorporated in the design of ACCESS: YouTube, where there are no visual or audio distractions (including no adverts!).

One of our most bought pieces of kit, came from observing a Tobii Dynavox assessment where the consultant used a wireless keyboard and trackpad to control the device away from the user.

We now include these keyboards with every school PC we setup to ensure that any intervention from the teaching assistant doesn’t require the device to be moved, or the client needing to be leant over, minimising any distraction.

We set up a huge amount of PCs, and it’s common to see them filled with bloatware, distracting pop-ups and adverts when they arrive from the supplier. Norton telling you constantly it’s expired, or some other nonsense app alerting you, is horrifically distracting and prevents users from concentrating on their work. For this reason, we immediately wipe every PC , turn off all notifications and install an ad-blocker to ensure a consistent distraction-free experience. We also ensure there are no passwords to login to the device (unless requested and manageable by the user), so there are no unnecessary barriers to using their equipment.

Principle 5— The Principle of Best Fit

“Technology should be compatible with all aspects of the user’s life”
Solutions should fit the personality of the individual…!

Currently we work with ~30 clients. That’s 30 homes, 60 parents, 40 siblings, 30 schools, 30 teachers, 30 teaching assistants, and over 100 NHS and Independent professionals including Physios, Occupational Therapists and Speech and Language Therapists. That’s a lot of people to consider when implementing a solution.

As with making the use of the equipment low-effort for the end user, we try to make it as little effort as possible to maintain and support for everyone else involved.

Little things we’ve done to achieve this:

  • Wheelchair-mounted wireless-joysticks are all charged directly from the chair, so carers don’t to remember to charge them
  • All our PCs come with TeamViewer installed allowing quick and easy remote access to fix minor issues
  • Cable ties everywhere to make sure everything is super neat at home and school
  • Giving users choice of colours or case where possible
  • Leaving PCs unlocked for personalisation

We need to remember that this equipment is going into a family home, so checking with the family about size and style of any furniture required, placement of equipment and preferred solutions (are they an Apple or Android family?!) is necessary to ensure consistent use.

Principle 6— The Principle of Practicality and Use

“Never forget why you started”

For a geek like me, this is an exciting job. It’s easy to run away with the fun problem-solving and solution-designing aspect of implementing technological solutions. However, we need to bear in mind there was an original reason for this problem.

We also have to bear in mind the ongoing costs, maintenance and transport considerations. Too many AT solutions are sitting in cupboards for being difficult to use, have bits missing – let’s not contribute to that further.

Principle 7— The Principle of Evidence Based Practice

“Stand on the shoulders of giants”

All practitioners should be doing this as a matter of course anyway, but it’s sensible to include this as part of the language used when implementing AT. Working together as a Multi-Disciplinary Team is essential, with all stakeholders. A lot of experimentation, failure and reflection is necessary to discover the best solution for a user. At Access: technology north, we insist on a minimum of termly interventions to review progress and development for our clients, as their needs, abilities and circumstances constantly evolve. Technology is such a fast-paced entity that constant CPD is also necessary to stay on-top of the every changing developments in hardware, software and approaches.

Access Technology North is an Independent Assistive Technology Consultancy based in the north of England. Our mission is enable greater independence for disabled children through the use of technology. Visit us at accesstechology.co.uk