Previous research into inclusive design has yielded several sets of inclusive design rules and guidelines. One such set, Sangelkar’s set of inclusive design rules, is the focus of this research.
Preliminary research has shown that Sangelkar’s rules are problem dependent in their effectiveness, and have been shown to be effective in designing more inclusive architectural products [3]. Here, architectural products are defined as products and environments for which the space around the product is an important factor in using the product (e.g. buildings, parks). The primary objective of this work is to provide evidence that inclusive design rules are also effective in designing inclusive consumer products. This work analyzes sets of inclusive design rules; first by observation, followed by an in-depth case study testing each design rule on a product that was originally designed for users without disabilities. These case studies analyze how inclusive design rules affect products, and what modifications these inclusive design rules lead to. We then study potential users’ and experienced designers’ opinions regarding the inclusivity of these products in order to gain insight on the effectiveness of the related design rule. The design rules are further analyzed in a second validation study. This validation study tasks participants with redesigning typical products using the given design rules. We analyze how the participants apply the design rules, and what effects they have on product inclusivity.
The design rules being considered in this chapter are a combination of Sangelkar’s actionfunction-inspired inclusive design rules and Clarkson’s human capability design guidelines.
Development of Combined Rule Set
As mentioned in the closing remarks of Chapter 2, combining Clarkson’s guidelines with Sangelkar’s rules allows us to create a single rule set with the combined insights from human capability data and inclusive product pairs. Clarkson’s guidelines are focused on human capability and measurement data, and thus provide insight into user activities (in the actionfunction diagram format) that may limit users. Sangelkar’s inclusive design rules are derived from comparing inclusive versions of products to their typical counterparts, and thus provide insight on current solutions to more inclusive functions. Moving forwards, we analyze the effects and effectiveness of the rule set formed by combining Sangelkar’s inclusive design rules with Clarkson’s human
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capability design guidelines. We call these combined rules human capability-sensitive design rules, and the combined rule set is shown in Table 7.
Table 7. Combined Rule Sets (Human Capability-Sensitive Design Rules)
User Activity Product Function Recommended Change User Activity Change Dexterity
Carrying, Moving, And
Handling Objects Transfer Human Energy Functional Easier, lower force Carrying, moving and
handling objects Import Solid No change Same as Typical
Carrying, moving and
handling objects Position Hand Parametric Easier
Grasping Position Hand Parametric Easier
Grasping Secure Hand Functional Easier
Grasping Position Hand Morphological Easier
Manipulating Guide Solid Morphological Easier, one application of
force
Manipulating Actuate Signal Morphological Pushing with fingers
Manipulating Guide Solid Parametric Easier
Manipulating Position Hand Parametric Easier
Manipulating Couple Solid Parametric Easier
Pulling Guide Solid Parametric Easier
Pulling Guide Solid Morphological No activity
Pushing with hand Guide Solid Parametric Same as typical
Pushing with fingers Guide Solid Parametric Same as typical
Turning Guide Solid Morphological Pushing with hand
Turning Regulate Electrical
Energy Parametric Pushing with fingers
Reach And Stretch
Reaching Position Hand Morphological Reach with single arm
Reaching Position Hand Parametric Easier
Reaching Guide Solid Morphological Not exerting force with
arm outstretched Locomotion
Bending Interface With Product Morphological No bending over
Changing Basic Body
Position Support Human Functional Grasping with hand
Maintain Body Position Position Human Parametric Easier
Moving Around Import Human Parametric Easier
Moving Around Support Human Functional Add in seating
Moving Around Support Human Morphological Aesthetically better
Moving around Secure Human Functional Better
Pushing with lower
extremities Guide Solid Morphological Pushing with hand
Sitting Guide Human Functional Better, grasping with hand
Standing Guide Human Functional Better, grasping with hand
Transferring oneself Import Human Morphological Better
Transferring oneself Import Human Parametric Easier
Communication
Perceptual Functions Interface With Product Morphological Easier
Perceptual Functions Indicate Status Functional Easier
Perceptual Functions Indicate Status Morphological Communication - various Hearing
Hearing functions Indicate Status Parametric Easier
38 Table 7. Continued
User Activity Product Function Recommended Change User Activity Change Hearing
Hearing functions Indicate Status Morphological Easier
Hearing Functions Export Signal Parametric Adjust volume/frequency
Hearing Functions Adjust Signal Functional Adjustable Volume
Hearing Functions Export Signal Morphological Easier, Natural Voice
Hearing Functions Export Signal Morphological Communication - various
Vision
Communication - Written Indicate Status Parametric Easier
Communication written Indicate Status Morphological Communication Braille Communication
-Nonverbal Indicate Status Parametric Easier
Seeing functions Indicate Status Parametric Easier
Seeing Functions Indicate Status Morphological Easier, reduce glare
39 Case Study and Experimental Approach
In order to test the efficacy of these design rules, we test each rule on a case by case basis.
The goal of this study is to analyze the application of these design rules on consumer products.
These cases show in detail the process of applying inclusive design rules to products, and provide examples of what modifications these rules may suggest. For each design rule, we have chosen a relevant typical product and developed an actionfunction diagram. We have also provided information on what difficulties a lesser-abled user may have with the typical product, and what needs that such a user may require. As the purpose of this study is to test the applicability and efficacy of these design rules, we have chosen products for which we have no knowledge of a preexisting inclusive alternative. We have made this distinction so as to avoid basing our modifications and solutions on prior knowledge and instead focus on the changes suggested by the relevant design rules.
Case Studies
For each case in this study, we apply the relevant design rule to the typical product’s actionfunction diagram, therefore creating a modified actionfunction diagram that will lead to a more inclusive design. Utilizing this modified actionfunction diagram, we develop and sketch a physical representation of a possible solution. For the cases in which we are applying multiple similar design rules, we develop a physical representation for both solutions and compare the results. The section below details one example of a case study done on the typical light bulb. The remaining 33 cases can be found in Appendix D.