Love a good model...

In this age of user-centred design, we are encouraged to consider the 'fit' of products, (and I say products from a marketing perspective - meaning anything, tangible or intangible, that meets a need).  Not only, Does it work? but -  Can I use it? and -  Does it solve my problem?  Your product may scratch very well, but does it scratch where there is an itch?  For me, one of the interesting tools presented during our Lifetec visit was the HAAT model (Cook & Hussey, 2002).  Given that most designers of AT are unlikely to require the products themselves, models such as these are particularly important as they guide designers to an understanding of their users requirements and the barriers to independence.

Figure 1. Human Activity Assistive Technology Model 

The CAT model further develops the HAAT model, to organise end-user information, Figure 2, and design specifications, Figure3.

Figure 2 CAT Model -  End-user information

Figure 3 CAT Model - Design Specifications

 Figure 1. Cook, A. M., and S. M. Hussey. 2002. Assistive Technologies: Principle and Practice, 521. 2nd ed. St. Louis: Mosby).
Figure 2 & 3 Hersh MA. 2011. The Design and Evaluation of Assistive Technology Products and Devices Part 1: Design. In: JH Stone, M Blouin, editors. International Encyclopedia of Rehabilitation. Available online: http://cirrie.buffalo.edu/encyclopedia/en/article/309/