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Inclusive Design Advisor: Understanding the Design Practice Before Developing Inclusivity Tools

Emilene Zitkus, Patrick Langdon, and P. John Clarkson

Journal of Usability Studies, Volume 8, Issue 4, August 2013, pp. 127 - 143

Article Contents


This paper forms part of an ongoing research project that has studied ways in which inclusive design could be accommodated into design processes in industrial contexts. Past research indicates that one way of addressing accessibility problems is by supplying designers with tools and methods (Beecher & Paquet, 2005; Maguire, 2001; Vanderheiden & Tobias, 2000). This would enable designers to evaluate the physical interactions that occur between users and new concept designs, as well as to understand their impact on users with limitations.

The next two sections analyze some of the accessibility evaluation tools and techniques that are currently available, and could be used by designers, and reviews common industrial design practices as they relates to these tools and techniques.

Accessibility Evaluation Techniques and Tools

The need to enable product design teams to understand end-user requirements has driven experts, for many years now, to develop an extensive range of techniques and tools. These techniques and tools vary in format and scope and include guidelines, user participation, and physical or digital simulation tools.


There is a range of checklists, standards, and guidelines suggested by many experts as a way to guide designers to address the needs of end-users (Nicolle & Abascal, 2001). For instance, the World Wide Web Consortium (W3C) has developed standards and guidelines for designing accessible websites (http://www.w3.org/TR/WCAG20/). Some guidelines are presented as lists of general user requirements that designers should cover in their new concept, whereas other guidelines are more specific in providing information about dimensions of a product or product features. For instance, the Access to ATM - UK Design Guidelines explores user’s anthropometric data and their relationship to product dimensions (guidelines are available at http://www.cae.org.uk/publications_list.html).

In some cases, guidelines are used very early in the design process to define the general user requirements that designers should consider when designing a new concept. In other cases, where the guidelines are more specific, designers can use guidelines as a checklist to evaluate their new design concepts. In the latter, the guidelines can provide information about physical characteristics that the new concept should include for users. For example, guidelines could include preferred user requirements for certain products or users, such as dimensions, materials, color, density, maximum noise produced, maximum force required, etc. The scope of guidelines varies from general requirements to specific information depending on the type of product under development. The guidelines’ data are normally presented in descriptive texts and tables.

User participation

User participation is included in usability tests, user observation, user co-designing, and, more recently, user theater. The impact of the results is directly related to the method used, the recruited sample of users, and the stage of the project where it is applied. If usability tests are applied during the design process and include some participants with disabilities, many issues that relate to inclusivity would be radically reduced, thus enabling more users to enjoy the benefits of inclusively designed products.

Direct user participation in the design process is a well known way to enable designers to understand users’ needs and desires (Allsop, Holt, Gallagher, Levesley, & Bhakta, 2010; Green & Jordan, 1999; Norman, 2002). This helps designers fulfil the needs of a broader range of the population, including elderly and disabled people. Users can participate in different phases of the design process:

Physical simulation tools

To help young, able-bodied people understand the limitations of physical impairments, designers developed an apparatus (approximately three decades ago) to simulate the loss of physical capability. These types of apparatus, or tools, have been used in lectures, workshops, and training sessions (Hitchcock & Taylor, 2003; Moore, 1985). Some recent versions of this tool include Third-Age Suit, Age Explorer, and Simulation Toolkit1. All of these tools have braces, pads, and other physical restrainers sewn into the suit. They also have fogged or yellow spectacles to limit the vision and, in some cases, earmuffs to decrease the wearer’s hearing capability. The Simulation Toolkit was created with adjustable features to enable the wearer to simulate gradual difficulties from different levels of impairments, a characteristic that is not present in the Age Explorer and the Third-Age Suit (Cardoso & Clarkson, 2007; Meyer-Hentschel, 2007).

Product designers can use these tools in a product’s conceptual phase to simulate an evaluation based on user disabilities. If the tool is used with similar products, the results help designers understand user problems and can design prototypes that alleviate those problems. If the tool is used during rapid prototypes trials, then the results might indicate the changes that should occur with the design under development. In both cases the outcomes rely upon the way the task is simulated and problems prioritized.

Digital simulation tools

Similarly to the physical simulation tools, there are digital simulation tools to evaluate a product’s design. There are a variety of digital human modelling (DHM) applications developed to simulate human interactions virtually (Duffy, 2009). These computer-based tools are integrated into CAD models that enable designers to assess design concepts during the conceptual phase.

Among the digital simulation tools available, the following tools include programming to highlight inclusive design approaches and are the most common in academia:

The simulation results depend on the anthropometric data set and the ergonomic methods used in the applications, as well as the task performance simulated by the designer. The task simulation is normally performed according to the designers’ assumptions, which might be defined by their knowledge of the product, the users, and the interaction the users will likely have with the product (Lämkull, Hanson, & Roland, 2009).

The Use of Accessibility Evaluation Techniques and Tools in Industry

Although the range of techniques and tools described in the previous section are currently available to evaluate accessibility in new product development, these tools and techniques have not been widely used by industry (Zitkus, Langdon, & Clarkson, 2011). According to past research, the industrial adoption of accessibility evaluation tools is strongly connected to their impact on the design process and the design activity. This means that such tools should be cost effective for the company and should be easily integrated to the time and budget allocated to the project (Vanderheiden & Tobias, 2000). Additionally the benefits of using these tools and techniques should be clear to the design team (Goodman-Deane, Langdon, & Clarkson, 2010). However, the following aspects of the accessibility evaluation techniques might affect acceptance in industrial contexts:

Despite the risk of incorrect assumptions, the digital simulation tools are the most integrated approach used by design teams among all the techniques and tools reviewed in this section. The integration of CAD software with accessibility tools facilitates quick feedback and stimulates design discussions during the design process (Loudon & Macdonald, 2009). Moreover, considering the industrial context, it is important to emphasize that the impact on the design process (time and budget) can be minimal when using CAD models. In our experience, the earlier a concept design meets the users’ requirements, the fewer the changes to the design process, and thus, those changes are likely to be implemented.

Figure 1 shows the accessibility evaluation techniques and tools in coordination with the design process.

Figure 1

Figure 1. The integration of accessibility evaluation techniques with the design process (also named concept development in the process adapted from Ulrich and Eppinger, 2008)

Apart from the guidelines, the other accessibility evaluation techniques and tools presented in Figure 1 are strongly based on task performance of a product. We recognize that there are design features in everyday products that by their user-demand exclude part of the population. For instance, some products have small buttons placed close together that make the buttons difficult to see and press for people with vision or dexterity problems. Other examples include products that are too heavy for elderly people to carry, products that use text fonts that are too small to read, or some products use foreground and background colors that are illegible for colorblind users. However, in spite of those major limitations, designers could still include small changes in their designs, such as having the option to change the font size or color or background color, to make a final product more accessible to a wider range of users—or consumers.

The approach of our research is to show that, in many cases, by making small changes in design features, designers end up with more inclusive products. Therefore, uncomplicated accessibility evaluation techniques and tools that overcome small problems could be integrated into the design activity. The subsequent sections present our investigation of how we demonstrated the inclusive design tool and then discussed the implications and challenges of using such a tool within industrial design practices.

1 All the three simulation apparatus are commercially available: http://www.age-simulation-suit.com, http://www.mhmc.de, and http://www.inclusivedesigntoolkit.com/betterdesign2/gloves/gloves.html.


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