Usability in Context
Colette Nicolle
Loughborough University

As you can see, I'm based at the Ergonomics and Safety Research Institute at Loughborough University, so you can see my background is ergonomics and human factors and my particular interest today is to ensure that smart living products and services are usable and safe and they meet the needs of the users.

But we're also soon to become part of the new Loughborough Design School, really exciting stuff for us at Loughborough.  I'd like to point out that I'm also very committed to the principles of what we call "inclusive design".  Just to give you a definition of that, if you haven't been using that term, it's the “design of mainstream products and/or services that are accessible to and usable by as many people as reasonably possible without the need for special adaptation or specialised design.”

So what I hope to do in the short time that I have available here is highlight the importance of all of these concepts that I've just mentioned in our discussion today.

Now, here is a photo from one of our user trials looking into the usability of technologies in the home.  The older user is using his computer, his digital camera and digital radio, CD player, DVD player/recorder.  His quote there is, "everything is so fragmented that I just keep phuphing about".  He was having problems in the use of everyday things and these problems may be down to the individual interfaces to each product.  But the problems could also be due to not having a mental model of how all of these technologies fit together, whether physically or cognitively.

So when introducing new and unforeseen functionality to technologies in the home, if you think it's complicated for us, just think how it's going to be for an older person or disabled person who is already working to the limits of their ability or their patience.

So what do we mean by "usability"?  This is the definition in ISO 9241:  “The extent to which a system, product, or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.”   So let's talk about the users for a minute. Who are they?  They are likely to be older and disabled. Are they highly trained in the use of technologies?  Do they feel comfortable in using technologies or are they novices to technology?  We also need to think about other users of the systems: secondary and tertiary users of the systems, people like yourselves, involved in developing and implementing smart living systems and products. What about specified goals?  Are the users able to do what they want to do with the system?  Are they able to achieve their goals in everyday living?  They need to achieve their goals with effectiveness. Can they actually do what they want to do with the products or the systems?  Will they achieve those goals with efficiency?  How much effort do they have to put into using these products or technologies?  Satisfaction - how do they feel about it?  Do they feel good using the technology, what about the ease of use of the technology or systems?

I would like to go into a bit more detail about context of use.  We are all here because we want to help disabled and older people lead easier lives in their homes and the context in which the smart living products or systems are going to be used needs to be considered across a range of different aspects. We talked a bit about the users and the tasks they are performing, the equipment, the products they are going to be using, but think about the environment in which these products or systems are being used. The environment includes the physical attributes of the environment, the lighting, the layout of furniture in the home, for example. Also, the environment includes the organisational aspects of the environment, work practices or the practices in the home. I won't dwell on that at all. The social aspects are important. Are there going to be other people nearby who can support them in the use of technologies?  What are their attitudes towards using technologies?  So all these different facets of context will impact upon the product and the system’s usability, and they could have an even greater impact on an older or disabled person who may be struggling across a range of capabilities.

Here we have the range of the capabilities that people may use when interacting with products:  reach and stretch, locomotion, dexterity, vision, hearing, cognitive abilities. The vast majority of product interactions will make demands onthe visual and the dexterous capabilities of the user.

I am going to draw from a bit of science here. I won't go into much detail at all, and want to thank my colleague Eddie Elton on the research he has been doing as part of the i~design3 project. I thank him for the figures I am going to give you now, without going overboard on the science - I promise you.

We have been doing relevant research, I feel, as part of the i~design3 project, funded by the Engineering and Physical Sciences Research Council. We have been working with the Engineering Design Centre and the Department of Psychiatry at the University of Cambridge and also the Royal College of Art Helen Hamlyn Centre.

We measured visual acuity (or the ability to see fine detail) at a distance of 1 metre for 38 people with a mean age of 74 years of age. We have done these measurements under four different lighting conditions that typically represent everyday environments where product interaction frequently takes place. We had to buy a street lamp and put it into the lab to show how well a person is able to see text when trying to read the interface on a product outside at night under a street lamp. We also used lighting at 150 lux, typical of in-house lighting. Also lighting similar to an overcast day at 6,000 lux and 40,000 lux, similar to a daylight situation. Under each of those lighting levels we measured visual acuity using the LogMar acuity charts at 4 different contrast levels, similar to the distance you would interact with everyday products:  90%, 70%, 50% and 30% contrasts levels.

The results showed the smallest letter size that 50% of the participants could read.   You can see I have highlighted the in-house lighting and the daylight lighting, which showed that when the luminance increases, a person is able to read text that is slightly smaller.  In daylight, for example, at 90% contrast, a person is able to read a font size of 1.8mm, but with in-house lighting, a lower level of luminance, the characters needed to be 2.3mm for at least 50% of the participants to be able to read them. So people needed larger font size as the lighting decreased and this was true across all contrast levels.  This demonstrates the importance of good size and contrast of text in order to make the interface to smart living products as usable as possible.  So this is something to keep in mind when designing the interface to any of the products.

I am now going to move away from the science bit to your own living room where the products may be found. We said already your TV screen can do so much more.  The TV screen can be the users' interface for doing all sorts of things, for controlling your audio visual equipment or controlling room temperature, reminding us to take medication, when dinner is ready, information on when the next bus is going to arrive.  All of this information needs to be provided in a form appropriate to individual needs.

We have been talking about this for some years now. I want to take you back to some research projects that we worked on from 1992 at Loughborough University – the first two as part of the European Commission’s TIDE programme (Technology Initiatives for Disabled and Elderly people). TIDE ASHoRED project (Adaptable Smarter Homes for Residents who are Elderly and Disabled people).  In that project we defined the problems of daily living and user needs requirements of older and visually impaired people living in their own homes, and then users’ needs were addressed in smart home demonstrators in Germany, Finland and Spain.  One of the examples was a smart washing machine. I won't go into detail about the project but it was followed by another project called CASA (Concept of Automation and Services for people with Special needs). That project did not just look at stand-alone intelligent home technologies but also how to integrate the hardware with outside support services. The emphasis in that project was on monitoring the home, mainly for safety reasons like home security, alarm and monitoring services, and advisory services. In both of those projects back in the early to mid-90s, some of the findings were that, first of all, the systems were made up of a large number of elements. We know that.   Also that different systems require careful integration, but there has been little integration of different systems and performance of the whole automation system. Sound familiar? 

Then following on from that research, for the Department of Trade and Industry, in support of The Application Home Initiative, or TAHI, we did a review of smart home sites and divided the sites up into those sites focusing specifically on older and disabled people, and also sites not specifically focusing on older and disabled people but could provide benefits for these people if the technologies were designed and evaluated with their needs in mind. Some of the themes that came out of that review were, first of all, the inherent complexity of the housing sector and service provision - we know that - and the complexity of market forces in this sector – for example, housing associations and charities, mainstream office automation, social alarm providers, specialist environmental control manufacturers and service providers.

So we can see that in going back some years there are many systems around to address the needs of older people, but they are usually stand-alone systems. What we need is a consistent, seamless interface to fully integrate systems and also change in policy to bring it about. Guidelines are needed that will not restrict development of new technologies, will allow interfaces to be tailored to meet individual needs and will be adopted by all or most of the relevant buyers. 

Individual needs are very wide ranging and you have to remember there are many people with multiple disabilities so we can run through just a range of these. Impaired vision: they may have difficulty reading displays and labels on buttons and controls. They may have reduced motor control, find it difficult to select and press small keys. Loss of use of limb: they may only be able to operate the device with one or no hands. Difficulty to reach poorly positioned equipment. Impaired hearing: they may be unable to hear auditory sounds like warnings or confirmations. Reduction in short-term memory: they may have difficulty memorising commands and codes, and other cognitive problems may restrict their processing of information. They may have possible lack of confidence in using new technology. (Also I give my thanks to my colleague, Martin who is here somewhere , I pinched that slide from your lecture notes.)

I always like to go back to the 7 Principles of Universal Design to meet these wide ranging needs.  The 7 principles were developed at the Centre of Universal Design at North Carolina State University. Many of you may be familiar with them. Running through quickly, Equitable Use is a high level guideline. The design must be useful to any group of users. Using standard interface elements that are going to be compatible with accessibility aids if the user needs to use them.

Flexibility in use: the design must accommodate a wide range of individual preferences and abilities. For example, allowing users to choose between different modes, whether it be sound or visuals or text or graphics.  Simple and intuitive use: that's easy enough to understand. The design must be easy to understand and use regardless of users experience, knowledge, skills or concentration.

Perceivable information: the design must communicate necessary information effectively to the users regardless of ambient conditions or the user’s sensory abilities. Tolerance for error: the design must minimise hazards and adverse consequences of accidental or unintended actions. Low physical effort: the design must be usable efficiently, comfortably and with minimum fatigue. Finally, Size and space for approach and use: appropriate size and space must be provided for approach, reach, manipulation and use regard less of the user’s body size, posture or mobility.

I would like to break these down, start to get a little bit more specific, and then I will get more specific still.

We should be looking for guidelines which support and promote first of all suitability for the context of use, so ensuring the interfaces can be customised to individual requirements.  Does the system provide benefits compared to alternative ways of performing the same task? Secondly, ease of use: a level of complexity a younger person may take for granted may mean the system isn't going to be acceptable to an older person who has less experience in using technology. Simple functionality: you just might have to make a trade-off between more functions and a complex structure or interface and simpler systems with reduced functionality. Good feedback, so where possible, think of redundant feedback where a person can choose between auditory and tactile feedback to show status of the system. Safety in use: technology shouldn't be introducing higher levels of risk than if the technology were not present.

Reliable and fail-safe operation: if the system fails you should not be putting somebody in a position of danger due to the failure of the system or the failure of the environment. If there's a power cut you have to make sure you can open the door to get out. Discouraging passivity: is there a danger of providing too much support, therefore encouraging a person to become more passive in their home with over reliance on technology? 

Design aesthetics: attractive products. You want attractive products that don't stigmatise the user, products that everybody is going to want to use in the true spirit of inclusive design. Finally, ethical considerations has already been mentioned, of course a crucial area, not invading somebody's privacy without consent. I always think in some of the research we have done, there's also the danger of introducing a fantastic new system in somebody's home as a prototype, the funding of the project finishes and the system can't be supported. We have to think about these things before you test these systems in somebody's home.

Getting a little bit more specific now, and I think compared to the last slide this is the easy bit. Considering the interface to any individual products, you want to be consistent, you want to be integrated, but we need to consider the size and contrast of the font that I have mentioned earlier, the colour contrast, the style of font that is easy to read, the layout, appropriate spacing. It is all good interface design – it is nothing new. Clear labelling. Understandable symbols, familiar language, free from jargon. We have to think about all these things. In other words, keep it simple. Keep it as simple as possible.

I would like to quote here from Jeremy Myerson at the Royal College of Art Helen Hamlyn Centre. He was interviewed on the You and Yours radio programme on BBC 4, speaking about the Design Museum's “Ergonomics: Real Design” exhibition.  He said: "Economics determines the commercial value of design. Ergonomics determines the human value of design."  If we can do this right, there will be something in it for everyone. Not only do we need to consider the moral duty for everybody to consider this challenge, but it also is going to be a good objective for business. And as we have been saying all day we need to bear in mind that good design for older people and people with disabilities is good design for everyone.

So it is now time to work together on this coherent policy in the provision of smart living systems, and I think this seminar really kicks this off to a good start.