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Assistive Technology Performance Expansion/Compression – Erik Kondo

Performance Expansion vs. Performance Compression

When people think about assistive technology (AT), they typically think about the benefit it provides. It has been well established that AT provides tremendous benefits to increase the performance of the people who use it. What is less considered is how AT can also hinder some people's performance.

The use of AT always comes with benefits and disadvantages. The tradeoff of these benefits/disadvantages depends on the individual factors of the person involved. Ideally, the AT will provide more advantages than disadvantages, but this situation is not always the case.

I find it conceptually useful to divide AT devices into two broad categories. These categories are Performance Expansion and Performance Compression. Where the categories of performance relate to the distribution of performance outcomes created by a group of demographically similar people using the device.

For example, a bicycle is an AT device. Now imagine a group of bicycle riders that are relatively similar in terms of age and general fitness level. If we were to create an objective bicycle test that measured the performance of each bicycle rider in specific metrics of sprint and distance speed, maneuverability skills, hill climbing capability, etc., there would be a wide distribution of the results from the highest performers to the lowest performers.

The bicycle is an example of AT that creates Performance Expansion. It has the ability to enable some people to greatly increase their performance. On the other hand, other people will have lower increases in performance which mirrors the natural varied distribution of human ability. It is a performance multiplier where the level of “multiplication” will vary according to the individual.

In contrast, an AT device that creates Performance Compression will result in a narrow distribution of performance outcomes among a similar group of people. In this case, the AT device has the effect of creating a ceiling on performance regardless of the individual's ability. For example, assume a group of people with spinal cord injury. If each person in this group is tested on their performance output using a standard power wheelchair, the distribution of results would not vary very much from person to person even though the physical capabilities of each person may vary widely.

A standard power wheelchair (or manual hospital wheelchair) will increase some people's performance and lower other people's performance (relative to some other mobility device). Thus, making the resulting performance distribution of the group narrow. Hence, creating Performance Compression.

When an AT device creates Performance Compression, it means that many of the users are held back (hindered) by the limitations of the device. For these people, the device creates absolute performance reduction rather than improvement.

Assistive Technology devices for the able-bodied population typically create Performance Expansion. In fact, it is the high performance of the well-known expert users that serves as an important driver of popular interest in the device.

The general population is inspired to follow the exploits of such leaders even if they do not have the personal ability to mimic their high level of performance. How many young women took up archery after watching the Hunger Games? Look what Tony Hawke did for skateboarding. In such a situation, the AT device undergoes a cycle of continuous improvement as the device is innovated to enhance an ever increasing level of performance from the top level users.

The evolving cycle driven by experts leads to improvements for all the users of the device. Performance Expansion is the result of a healthy cycle of AT device innovation and improvement.

Conversely, it is not uncommon for AT devices designed specifically for wheelchair users to exhibit Performance Compression. This happens because the AT device is intended for universal use by a wide variety of people with disabilities regardless of their inherent differences. In other words, the AT device that is designed to "work" for everyone also works well for nobody.

For example, wheelchair users are typically seen as a monolithic group where what works for one, will work for all, and what doesn't work for one, will not work for anyone else. The concept of wheelchair high performance is not considered. Therefore, AT devices for wheelchair users are catered to improvements of low end performance at the expense of high performance. There are few expert driven improvements. Generally speaking, AT devices for people with disabilities typically have a static and relatively low performance ceiling.

Notable exceptions to this situation are the Performance Expansions created by adaptive recreational devices for alpine skiing and mountain biking. This adaptive equipment follows the same cycle of improvement and innovation as able-bodied devices. The culture around this adaptive equipment is performance centric and it shows. Not only has the absolute performance ceiling increased, the breadth of people with disabilities involved in these recreations has expanded to include more than just top athletes.

Distinguishing between Performance Expansion and Performance Compression is a mechanism to increase discussion and understanding about the advantages and disadvantages of assistive technology devices.  It highlights the importance of enabling high level performance as an important output of adaptive AT, and the acknowledgement that AT users are a diverse group of people with inherent differences in needs, desires, and abilities.

Improving and developing assistive technology is more than just coming up with newfangled devices for people with disabilities. It requires having a deep understanding of all the outcomes, side effects, and unintended consequences that are created by the use of the devices.


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