Towards Web Accessibility Guidelines for People with ...

Towards Web Accessibility Guidelines for People with Autism Spectrum Disorder

ABSTRACT In this paper, we describe a proposal set of web accessibility guidelines for people with Autism Spectrum Disorder (ASD) to help web developers to design accessible web interfaces for these users. The guidelines were extracted from a revision process of 17 works published between 2005 and 2015 including international recommendations, commercial or academic software and peer-reviewed papers. We identified 107 guidelines that were grouped in 10 categories through affinity diagram technique. Then, we systematized the guidelines in each group according to similarities and duplicated statements, generating a set of 28 guidelines. As a result, we evidenced best practices to design accessible web interfaces for people with ASD based on well succeeded solutions presented in works of different contexts. With those results, we aim to contribute to the state of the art of cognitive web accessibility. Therefore, we made the set of guidelines available in a repository on GitHub.

CCS Concepts • Human-centered computing ➝ Web-based interaction • Social and professional topics ➝ People with disabilities • Human-centered computing ➝ Accessibility design and evaluation methods.

Keywords Web Accessibility; Autism; Guidelines; Universal Design; Computer Systems for People with Autism.

1. INTRODUCTION Autism Spectrum Disorder (ASD) is a syndrome which affects three developmental abilities: social, communication and interest skills [1, 19, 21]. People with ASD often present difficulties such as interaction with another people, verbal and non-verbal expression, imagination and a restrict repertory of interests [1, 8]. As a spectrum, ASD has a myriad of characteristics and severity degrees related to the level of impairment of skills, from mild Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. SAC’16, April 4-8, 2016, Pisa, Italy. Copyright 2016 ACM 978-1-4503-3739-7/16/04…$15.00.

http://dx.doi.org/xx.xxxx/xxxxxxx.xxxxxxx

(high-functional autism) to severe. As soon as it’s diagnosed, ASD has effective treatments to minimize the impact of the impairment of skills and improve life quality of people with the syndrome and their families [1, 3, 19, 21]. In the past 20 years, computer technology has been used as a support tool for parents, therapists, educators and people with ASD [2, 3, 15, 23]. Previous works showed that people with ASD are interested in technology [23] and that is benefic to a) develop their abilities [14, 15, 17, 26]; b) facilitate their lives [5]; and c) be a helpful tool for pedagogical, therapeutic and everyday life activities [9, 10, 17], independent of age. Nowadays, devices exploring natural interactions and direct manipulation with touch screens such as tablets increase technology acceptance by these users [18, 22, 24, 26]. However, even having some successful solutions available for this audience, software developers still have a limited knowledge on how to develop native or web-based applications suitable for people with ASD. Other cognitive disabilities also are challenging for developers. This happens mainly because they still don’t know how technology is used in these users’ life [23]. When we analyze the web context, web developers and designers have a lack of experience working with accessibility [13] and, when they have it, it is usually only about people with visual disabilities. Another bias is that we have few Human-Computer Interaction (HCI) guidelines to help web developers design for people with ASD [15, 16]. Although specific literature provide some clues [4– 7, 11, 23, 27], the state of art regarding cognitive web accessibility is lower than expected [7]. HCI guidelines provide an understandable knowledge about needs and preferences of people with ASD and can help web developers understand how technology is used by these users [25], also allowing web access equity [7]. Thus, researches are needed to investigate which design features are critical to provide therapeutic and pedagogical effect for people with ASD in order to understand the potential impact of technology in their change of behavior [10, 29] and provide a formalization of this knowledge for web developers and designers. In this paper, we describe a proposal set of web accessibility guidelines for people with ASD to help web developers to design accessible web interfaces for these users. These guidelines systematize and formalize recommendations and best practices extracted from literature and reviewed software.

ASD and theoretical investigation about usability and accessibility issues not exclusive for people with ASD;  Target or audience: works involving or designed mainly for children with ASD or other developmental disorders. Phase 2 – Extraction

2. METHOD The process to identify, extract and systematize the guidelines presented in this works was conducted in three phases: Phase 1 – Studies selection We selected works about accessibility for people with ASD and other cognitive or neuronal disabilities published or developed between 2005 and 2015, analyzing international recommendations, mobile and desktop applications, universal design approaches for educational purposed and peer-reviewed papers published in conferences and journals (Table 1). It was considered the following criteria for selection:  



On this phase, we performed a triage to extract recommendations from selected works, where we identified 107 potential recommendations and best practices. Subsequently, we executed a process to group them using the affinity diagram technique, in order to arrange the extracted statements in logical sets according to the patterns we could identify in each statement. This process resulted in ten categories of guidelines (Figure 1). Finally, we did a second grouping process to combine analogue recommendations, refine the statements and systematize the final set of guidelines.

Country: the intention was to identify relevant recommendation from different cultural origins, in order to extract universal guidelines; Platform: most of works approaches touch-screen and mobile devices or web platform, however, we also Phase 3 – Consolidation considered works that present platform-agnostic The last phase involved a refinement process of each guideline recommendations; statement and the write of their detail description, including how Research/work purpose: for peer-reviewed papers, it to implement the guidelines and their respective importance. was considered software developed for people with Table 1: Overview of selected works

Classification

Author W3C [4]

International recommendation

Software for people with ASD

Peer-reviewed papers

Not related to technology, but involve universal design

Year

Country

Platform

Extracted recommendations

Target

2015

WebAIM [6]

2014

Abou-Zahra [11]

2012

Puzzle Piece [24]

2014

6 United States

United States

Web

Tablet (native application)

People with cognitive or neuronal disabilities

17

People with ASD

3

People with disabilities in language and communication skills

5

6

Proloquo2Go [22]

2014

Carrer et al.[3]

2009

Brazil

Desktop

People with ASD

2

Darejeh and Singh [5]

2013

Malaysia

Desktop

People with low digital literacy

7

Silva, Salgado and Raposo [26]

2013

Brazil

Muñoz et al.[18]

2013

Chile, Brazil

Sitdhisanguan et al. [27]

2012

India

Weiss et al. [30]

2011

Israel, Italy

Millen, Edlin-White and Cobb [15]

2010

England

Battochi et al.[2]

2009

Italy

Putnam and Chong [23]

2008

Friedman and Bryen [7]

Multitouch tabletop

10

Tablet (native application) Tangible User Interface Multitouch tabletop

4 4 People with ASD

4

Desktop (Virtual Reality)

3

Multitouch tabletop

3

United States

Unidentified

2

2007

United States

Web

People with cognitive or neuronal disabilities

20

Lau, Yuen and Lian [12]

2007

Hong Kong

Desktop

People with ASD

6

UDL Center [28]

2012

United States

N/A

Unidentified

5 Total

107

3. RESULTS 3.1 Overview of works Through a review of literature and available softwares, we selected 17 works according the criteria of Phase 1 presented in Section 2, divided into international recommendations (3), software for people with ASD (3), universal design guidelines for learning (1) and peer-reviewed papers (10). The selected works came from nine countries. Although contributions from United States correspond to 47% of works, it was still possible to bring cultural diversity from different countries. Regarding platform, this work is focused on web-based interfaces, but we selected works exploring distinct platforms and applications such as Virtual Reality, Multitouch Table and native (desktop or mobile) due to possibility to generalize recommendations and interaction patterns that can be platform-independent. Most of the works are related to technology specific for people with ASD, although all works from International Recommendations are not exclusively focused on ASD.

3.2 Category of Guidelines On Phase 2, after extracting the potential guidelines, we grouped all 107 recommendations and best practices using affinity diagram technique, where they were organized based on a similarity criterion. This process resulted in ten categories (Figure 1) carefully labeled to represent common elements in web interfaces.

preferences. However, one of the biggest challenges for people with ASD when using web are: a) to focus or comprehend lengthy sections of text [6]; and b) to understand visual/textual information due to inaccurate visual and textual communication [4, 5]. It is worth mentioning that Visual and textual vocabulary is recommended to be the first concern for developers and should be complemented with Redundant representation in order to increase the potential of being understood. As people with ASD, especially children, may be uncomfortable with certain distractive elements and also present some difficulties regarding focus and attention, Engagement guidelines are important to work memory, attention and reading skills on the web interface. Table 2: Distribution of extracted recommendations between categories and quantity of works referenced in each category Category

Extracted recommendations

Referenced works

Engagement

12

9

Affordance

8

6

Visual and textual vocabulary

26

9

Customization

14

10

Redundant representation

12

7

Multimedia

10

9

Feedback

8

8

System status

6

4

Navigability

7

4

Interaction with touch screens

4

4

Total

Figure 1: A visual schema of each guideline category considering common elements present in websites and web application from different domains. The categories are: (1) Engagement; (2) Affordance; (3) Visual and textual vocabulary; (4) Customization; (5) Redundant representation; (6) Multimedia; (7) Feedback; (8) System status; (9) Navigability; (10) Interaction with touch screens. On Table 2, it is presented a summary of recommendations extracted on the first triage, where is observed that the most critical interface design aspects are related to Visual and textual vocabulary, Customization, Engagement and Redundant Representation, according to the number of extracted recommendation and amount of works from where we extracted those recommendations. At first, we had a hypothesis that Customization guidelines would be critical due to the diversity of characteristic of people with ASD as customization allows them to be in control and to tailor the interface according their

107

The final step on Phase 2 was a second arrangement process to generate unique guidelines and reduce ambiguity and redundancy, since several recommendations in each category, from different authors, presented similar statements. As a result, we would formalize a set of 28 guidelines distributed in the ten categories, as presented on Figure 2. The guidelines from Visual and textual vocabulary, Customization and Engagement represent about 43% of all guidelines, reinforcing their importance when designing interfaces for people with ASD.

Figure 2 - Amount of unique guidelines generated for each category after systematization and summarization

3.3 Set of Guidelines The consolidated guidelines compound a set of 28 web accessibility recommendations to design and develop websites and web applications more suitable for people with ASD. As shown on Section 3.2, the guidelines are distributed in ten categories and each one has a strategic scope regarding interface and interaction aspects of a web interface. We describe in the following sections the scope of each category and the proposed guidelines along with the authors.

3.3.1 Engagement The guidelines of Engagement present recommendations regarding focus, attention and strategies to help the users to interact with the system (Table 3). These guidelines address interface design issues and intersect with recommendation on “Feedback” and “Visual and textual vocabulary”. Table 3: Set of proposal guidelines for Engagement Guideline 1.1. Avoid using elements that distract or interfere in focus and attention. In case you use it, provide options to suppress those elements on screen. 1.2. Design simple interfaces, with few elements and which present only the features and content need for the current task to be performed by the user 1.3. Use blank spaces between web page elements to separate different contents or focus the user attention on a specific content 1.4. Provide clear instructions and orientation about tasks to ease the user understanding of the content and the content language, in order to stimulate, motivate and engage the user

Author(s) [6, 11, 26, 28]

[5, 12, 18]

[6, 7]

[11, 23, 26]

3.3.2 Affordance Guidelines in this category address issues to design interface elements that clearly identify how they work without a deep investigation or a high cognitive effort (Table 4). Reducing cognitive workload is an important accessibility concern when designing interfaces for people with ASD. Consequently, interface designers and web developers should pay attention with the web page element that may not afford clearly if they are clickable, draggable, pushable, etc. Table 4: Set of proposal guidelines for Affordance Guideline 2.1. Similar elements and interaction must produce similar, consistent and predictable results 2.2. Use bigger icons, buttons and form controls that provide appropriate click/tap area and ensure that the elements look clickable 2.3. Provide immediate instructions and feedback over a interaction restriction with the system or a certain interface element

Author(s) [5, 6, 11] [5–7, 26]

[2]

3.3.3 Visual and textual vocabulary This category presents the most important recommendations, according to works we analyzed. They address the proper use of text and images considering particularities of people with ASD.

About 50% of the works present concerns about text structure, language, verbal and pictorial communication, reading flow and color contrast. In guideline 3.2 we consolidated contributions from four works [4–6, 11] and eight recommendations about the use of proper language. The guideline 3.4 summarizes five similar recommendations extracted from three works [12, 18, 30] related to real world representation of icons and interaction patterns. As people with ASD may face barriers to understand information and decode language, the guidelines of this category (Table 5) can improve the aspect of engage for communication [23] and work social and communication skills. Table 5: Guidelines for Visual and textual vocabulary Guideline

Author(s)

3.1. Colors shouldn’t be the only way to deliver content and the contrast between background and objects in foreground must be appropriate to distinguish items and distinct content or relate similar information 3.2. Use a simple visual and textual language, avoid jargons, spelling errors, metaphors, abbreviations and acronyms, using terms, expressions, names and symbols familiar to users’ context 3.3. Be succinct, avoid writing long paragraphs and use markups that facilitate the reading flow such as lists and heading titles 3.4. Icons, images and label of menus and actions should be compatible to real world, representing concrete actions and everyday life activities in order to be easily recognized

[6, 7, 20, 27]

[4–6, 11]

[6, 7]

[12, 18, 30]

3.3.4 Customization Guidelines from Customization category address recommendation to enable users to tailor interfaces according their needs (Table 6). It is the second most important category and allows users with ASD to adjust the interface more comfortably to them, considering that the syndrome presents a myriad of characteristics and it is often risky to identify patterns between people with ASD, such as colors preferences. Table 6: Set of proposal guidelines for Customization Guideline 4.1. Allow color, text size and font customization for interface elements 4.2. Provide options to customize information visualization with images, sound and text according to individual user’s preferences 4.3. Provide options to customize the amount of element in the interface, their arrangement and enable features personalization 4.4. Enable a reading or printing mode for activities involving reading and concentration

Author(s) [4–7, 22] [7, 15, 22, 23, 28]

[15, 22, 24, 26] [4, 7]

3.3.5 Redundant representation Redundant representation (Table 7) along with Multimedia refer to guidelines reinforcing that information should not be linked exclusively to a format (text, image or audio). Multiple representations (especially graphical) and support language disabilities work as a content supplement [20] and contribute with enrichment of user’s repertory [3, 26].

Table 7: Guidelines for Redundant representation Guideline

Author(s)

Table 10: Guidelines for System status

5.1. The website or web application must not rely only in text to present content. Provide alternative representations through image, audio or video and ensure that they will be close to the corresponding text 5.2. Symbols, pictograms and icons should present a textual equivalent near to facilitate symbol understanding and contribute to enrich user’s vocabulary 5.3. Provide audio instructions and subtitles for texts, but ensure that this is not the only alternate content representation

[3, 6, 7, 15, 28]

[7, 26, 28]

[7, 12]

Complementing guidelines from Redundant Representation, Multimedia’s guidelines detail the proper use of multimedia in web interfaces to work memory, attention, visual and textual understanding and sensorial integration of people with ASD (Table 8). Table 8: Guidelines for Multimedia Guideline

Author(s)

6.1. Provide information in multiple representation, such as text, video, audio and image for better content and vocabulary understand, also helping users focus on content 6.2. Allow images magnification for better visualization and ensure they continue to be understandable when enlarged 6.3. Avoid the use of disturbing and explosive sounds, like sirens or fireworks

Author(s) [6, 26] [6, 7] [27]

The guidelines of Navigability present recommendation on navigational structure between web pages. Large amounts of information and links contribute for a bad experience for people with ASD (Table 11). Therefore, the designer is recommended to provide to the interface: a) a simplified navigation; b) consistent location indicators; and c) sequential navigation, when applicable. Also, it’s important not to prevent users to be in control of the navigation flow. Table 11: Set of proposal guidelines for Navigability

[3, 5, 6, 11, 12, 22, 28]

[6] [27]

3.3.7 Feedback Providing feedback for actions performed in interfaces is a common usability recommendation independent of users’ characteristic. However, incomplete feedbacks or their absence are critical for people with ASD, particularly children due to their difficulties to pay attention, to deal with changes and to understand verbal instruction. Thus, feedbacks are important for people with ASD to guide them to perform tasks, understand the application behavior and predict the behavior of similar features or elements. The recommendations we extracted were very similar to each other, evidencing how this aspect is important and is consistently established in different works. As a result, we could summarize them into a single guideline (Table 9). Table 9: Guidelines for Feedback Guideline

Guideline 8.1. Present appropriate instructions to interact with interface elements, provide clear messages about errors and provide mechanisms to solve the errors 8.2. Allow critical actions to be reverted, cancelled, undone or confirmed 8.3. In interactive lessons and educational activities, it’s recommended allow up to five attempts before showing the correct answer

3.3.9 Navigability

3.3.6 Multimedia

7.1. Provide feedback confirm correct actions or alerting about potential mistakes and use audio, text and images to represent the message, avoiding icons with emotions or facial expressions

instructions and information related to changes in state of elements - Table 10).

Author(s) [2, 6, 7, 18, 24, 26, 27, 30]

3.3.8 System status The System status’ guidelines address recommendations about progress among tasks (clearly information about errors, help

Guideline 9.1. Provide a simplified and consistent navigation between pages, use location and progress indicators and present global navigation buttons (Exit, Back to home page, help) on every page 9.2. Avoid automatic page redirects or expiration time for tasks. The user is who should control navigation and time to perform a task

Author(s) [6, 7, 11, 12]

[6, 7]

3.3.10 Interaction with touch screen The last category presents a recommendation on the use of touch screen (Table 12). We consider this recommendation important since websites and web applications are increasingly being accessed through mobile devices with touch screens. Those devices present direct manipulation of interface elements, people with ASD tend to interact better to such devices [18, 26, 27] and their interface is considered to be more natural . Interfaces with direct manipulation require less physical efforts and present interaction patterns compatible with the real world. Table 12: Guidelines for Interaction with touch screen Guideline 10.1. Touch screen interactions should have the appropriate sensibility and prevent errors in selections and accidental touch in interface elements

Author(s) [2, 18, 22, 30]

3.4 Detailed guideline information The complete guidelines descriptions are available at the GitHub repository and website, in English and Brazilian Portuguese. An example of a detailed guideline is presented on Table 13. The extended description of each guideline is an additional resource we were concerned to provide to professionals who may not be proficient in web development and to other people who want to understand the rationale behind the guidelines.

Table 13: A detailed guideline description from category “Redundant representation”

Title

Description

ASD’s related characteristics

Why?

How?

Sources

5.1. The website or web application must not rely only in text to present content. Provide alternative representations through image, audio or video and ensure that they will be close to the corresponding text Websites and web applications must not rely only in text to provide instructions, commands or content, due to possible difficult people with ASD face with verbal communication abilities. Thus, it’s recommended provide content in multiple formats. Memory Attention Reading Verbal or linguistic understanding Visual understanding Sensorial integration Present content using multimedia (text, image and sound) reinforce the information idea, provide help in reading skills and may facilitate attention and memorizing for people with ASD. For children’s websites, redundant and alternative representations support literacy, may expand vocabulary and contribute with communication and collaboration skills. - Images such as illustration, diagrams and icons should be used to convey content and they should present a correspondent text as a (con)textual cue to help users understand content; - Ensure that multiple representation of the same information are near each other to reinforce comparison and association between the representations; - Use figures, icons and symbols near the corresponding text; - If the main content is visual or sound, provide a text alternative. [3, 6, 7, 15, 28]

4. CONCLUSIONS In this work, we investigate and systematize web accessibility recommendations and best practices to design web interfaces suitable for people with ASD. The guidelines are described to be intelligible for web developers, psychologists and pedagogues. As a differential from recommendations identified in selected works, we present an extended description to help implementing the guideline and understand the rationale of the proposed approach. Some guidelines may present technical details, however, our intention is that the guidelines can be applied by multidisciplinary teams and educational professionals involved with use of digital resources for people with ASD. Although the focus of the project is web interfaces, we carefully propose generalized descriptions for most guidelines in order to not link them with a specific platform. The idea is to enable their application to different interaction contexts.

The full set of guidelines is available at an open-source repository on GitHub 1 and at a website hosted in the same platform. Therefore, we hope this content may be complemented, distributed, derived and easily accessible to professionals and researches from different areas. Finally, the proposed guidelines should provide advances in the state of the art of cognitive web accessibility as: (1) support material to develop websites and web applications adapted to the needs of people with ASD, especially children; (2) a guidance documentation about best practices and potential challenges about interaction of people with ASD with interactive systems; (3) an open source repository of recommendations in constant update; (4) a complement to literature regarding the biases of web accessibility for people with cognitive or neuronal disabilities, adding techniques related to ASD.

4.1 Further Work The next step of this work involves the development of an educational web application using the guidelines to support the interaction design, followed by an experimental evaluation with children with ASD. The evaluation aims to observe how children react and interact with the application and collect a feedback to validate and improve the guidelines. Alongside, we intend to: (1) interview parents and teacher of children with ASD to understand their perspective about using technology as an educational and therapeutic resource in order to contemplate their viewpoint into the guidelines; (2) perform technical evaluation of the guidelines with web developers, accessibility experts and digital educational teachers involved with special education.

5. ACKNOWLEDGMENTS Our thanks to LAHMIEI researches, especially Prof. PhD. Celso Goyos for contributing with this work and providing the psychological subsidy.

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