Transformation Frameworks and Their Relevance in Universal Design
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Universal Access in the Information Society manuscript No. (will be inserted by the editor) Transformation frameworks and their relevance in universal design Silas S. Brown and Peter Robinson University of Cambridge Computer Laboratory 15 JJ Thomson Avenue, Cambridge CB3 0FD, UK e-mail: fSilas.Brown,[email protected] Received: date / Revised version: date Category: Long Paper – Some algorithms can be simplified if the data is first transformed into a convenient structure. Many algo- Key words notations, transformation, conversion, ed- rithms can be regarded as transformations in their ucation, tools, 4DML own right. Abstract Music, engineering, mathematics, and many – Transformation can be important when presenting other disciplines have established notations for writing data to the user and when accepting user input. their documents. Adjusting these notations can con- This last point, namely the importance of transfor- tribute to universal access by helping to address access mation in user interaction, is relevant to universal design difficulties such as disabilities, cultural backgrounds, or and will be elaborated here. restrictive hardware. Tools that support the program- ming of such transformations can also assist by allowing the creation of new notations on demand, which is an 1.1 Transformation in universal design under-explored option in the relief of educational diffi- culties. Universal design aims to develop “technologies which This paper reviews some programming tools that can are accessible and usable by all citizens. thus avoid- be used to effect such transformations. It also introduces ing the need for a posteriori adaptations or specialised a tool, called “4DML”, that allows the programmer to design” [37]. In his closing plenary address at ACM CHI create a “model” of the desired result, from which the 2001, Vanderheiden pointed out that this does not mean transformation is derived. designing one homogeneous user interface to fit every- body, since people have conflicting requirements and a “lowest-common denominator” interface would be lim- ited indeed: 1 Introduction “It can’t have a visual interface [because some people can’t see]; it can’t have an audio interface The transformation of data from one structure to an- [because some can’t hear];. you could design a other is a recurring theme in computer science and soft- brick...” ware engineering: Hence, a technology that fulfils (or partly fulfils) the – Compilers and other software development tools are aims of universal design is likely to include transforma- based on transforming the programmer’s input into tion functionality. This is not specialised design if it is an executable form (or, in the case of generative pro- customisable and extensible, and it is not a posteriori gramming, transforming it into lower-level code that adaptation if the transformation needs are foreseen a is to be compiled). priori in the original design. – Different programs (and in some cases items of hard- ware) use different data formats to represent the same thing, so conversion is often needed when ex- 1.2 Diversity and the need for general solutions changing data between them. For example, there are many converters between different document for- A popular misconception is that individual needs and re- mats, different sound and image file formats, musical quirements are nearly identical, and are adequately ad- score formats, etc. Object request brokers (ORBs) dressed by existing systems and hence there is no need and middleware frequently employ conversion. of further research. This section aims to show otherwise. 2 Silas S. Brown and Peter Robinson Individual needs and requirements are diverse and transcribe a piece of music from one notation into an- can be difficult to anticipate. A person’s ability to use other in order to make it accessible to a greater number data in printed form may be hampered by a print disabil- of musicians. Braille music also has numerous different ity, such as blindness, low vision, or dyslexia. It may also versions across the world. be hampered by educational and cultural differences. For Notations can be customised for different tasks, such example, the person may have learned a notation that as sequential reading, rapid overview, or detailed analy- is different from the one being used in the presentation. sis. Often it is desirable to omit or include certain details Motor disabilities may limit data entry and interactive depending on how the document will be used, because navigation with notations. people with print disabilities are frequently unable to skip over unwanted information at speed. Additionally, Diversity of print disabilities. The diversity of print educational establishments can customise notations for disabilities is frequently glossed over in the literature. pedagogical purposes. Many papers use the phrase “blind and visually im- Data entry is another task that can call for alter- paired” when discussing designs for blind people, imply- native notations, since optimising for input and editing ing that blind people and people with low vision have is different from optimising for reading. Even direct- similar interaction requirements; in fact, many with low manipulation interfaces sometimes use a hidden input vision use their residual sight as much as they can [25]. notation in their controls. For the sake of usability, there Other papers (e.g. Hermsdorf et al. [16]) assume that the is usually some compromise so that the input and out- needs of all partially-sighted people are much the same. put notations are conceptually similar, but this can be Jacko et al. [17, 18] show that this is not the case, and overshadowed by a disabled user’s accessibility needs (for suggest that individual users’ needs can be determined example, someone with extreme typing difficulties might by clinical assessment. Even this can be difficult in the prefer a terser input notation even if it means more train- case of some eye conditions, such as nystagmus, which ing). can vary over time and can produce different perceptual results for different people [39]. Some users need to be Multiple and unforeseen needs. Although it is common given control over the presentation themselves, as Gre- practice to focus on one need at a time, it is possible to gor and Newell explain for some cases of dyslexia [14]. envisage individuals who have a combination of several Many industry-standard applications already allow of the above-mentioned requirements, as well as addi- the customisation of fonts, sizes and colours, but it can tional ones that have not been anticipated by research. be difficult and is not always reliable. In the first author’s Hence, the need arises for general solutions, i.e., systems personal experience as a person with low vision, the cus- that truly include as many people as possible by being tomisation of applications frequently exposes bugs in the adaptable to new situations that were not explicitly con- display code; these can render the application unusable sidered at design time. and are rarely fixed in a timely manner. Further, few of these applications allow the layout of structured data to be changed to compensate for the reduced viewing area 2 Special-case transformation systems to text size ratio (see Section 2.2). Different layout algo- rithms can sometimes make the data easier to navigate This section discusses some illustrative examples of sys- around by people who have difficulty fixing their gaze, tems that use transformations to assist people with dis- and this requires additional customisation. abilities. The systems are “special case”, not because their primary purpose is to support disabled users, but Disabling circumstances. A document may have to be because the transformations they employ are limited to used in unusual circumstances that are effectively dis- one or two domains (such as Web pages, or mathematics) abling. This includes the use of restrictive hardware, and, although they might permit some customisation, such as small displays on mobile telephones, which they cannot easily be programmed to handle completely present a problem similar to that of large print on nor- new transformation tasks. This can be the case even in mal displays, as the ratio between the viewing area and systems that are examples of universal design. the text size is reduced, and therefore layout and naviga- tion need careful consideration. Adjusting the notation can help in this case also. 2.1 Assistive technologies for print disabilities Specialist notations. Educational background can con- In 1972, Rubinstein and Feldman proposed a Braille tribute to the requirement for an alternative presenta- terminal for blind computer operators [34]. Computer- tion. A good example of this is in music. Besides West- driven reading machines for the blind were also con- ern staff notation, musicians use various tablature and ceived at that time [2]. During the 1980s, when MS– instrument-specific notations, as well as sol-fa, Chinese DOS was the industry standard, many companies (such Jianpu notation, and others, and it is often possible to as Cobolt Systems, Dolphin Systems, Techno-Vision and Transformation frameworks and their relevance in universal design 3 PulseData) marketed “adaptive” or “assistive” technolo- 2.1.1 Application-level transformations Because of the gies for blind DOS users. These adaptations usually in- above-mentioned problems with assistive technologies, volved a combination of speech hardware and screen- Raman [32, 33], Zajicek et al. [46], and others adopted reading software. Screen magnifiers for partially-sighted the approach of implementing specialised applications people were also common, and some Braille displays were to cater for the needs of blind people, rather than try- available, although the latter were more expensive and ing to adapt industry-standard systems that were not required knowledge of Braille, which not all blind people originally designed for the purpose. Raman extended had [30]. the EMACS editor with a speech interface that is com- Pitt and Edwards [30] evaluated a screen reader and pletely different from its visual interface.