By M. Benassaya – User Experience & Accessibility Expert at SQUAD
With the evolution of the web and the central role that digital technology plays in our society, interfaces are becoming increasingly complex and rich, with a wide variety of interactions. Many everyday tasks, whether administrative or leisure-related, such as booking transport tickets, can be carried out online. These types of tasks may require a variety of high-level cognitive processes (searching for information, reading, understanding, comparing results, decision-making, entering information, etc.). A sighted person is aided by structure and visual cues to complete a booking task. These structural and formatting properties facilitate the implementation of a non-sequential navigation strategy. While current accessibility standards and assistive technologies tend to allow the visual structure of web pages to be reproduced for the user, this reproduction remains limited and highly dependent on the design of the web pages. Through an analysis of three online ticket booking sites that comply with accessibility standards, we seek to assess whether the absence of transcription of these elements hinders the understanding and navigation of blind people when performing a booking task.
1. ISSUES AND HYPOTHESES
Despite the undeniable technical and political contributions associated with the implementation of the Web Content Accessibility Guidelines 2.0 (WCAG 2.0) (W3C, 2013) in terms of web accessibility, their application on a website only guarantees what is known as normative accessibility and not effective accessibility (Giraud, 2014). Even if this normative approach theoretically allows for the successful completion of a navigation task, it does not guarantee efficiency and satisfaction in terms of usability (ISO, 1998). According to Power et al. (2012), only 50% of accessibility issues encountered by blind users when browsing the web can be resolved by the WCAG 2.0 recommendations. Performing a complex task with a visually rich and interactive interface, such as booking a transport ticket, therefore implies that accessibility standards reach their limits in terms of usability. This is due to the limited consideration of visual and structural cues (Issa et al., 2009) (spacing, layout of areas, typographical marks, visual salience, etc.) that support cognitive processing when performing the task and limit disorientation. For example, Plégat-Soutjis (2004) indicates that visual cues present within the structural and graphic organization are involved in the semantic understanding of a website. Similarly, Baccino and Drai-Zerbib (2015) argue that spatial coding, i.e., the processing of text with its spatial location, provides assistance in terms of memorizing and identifying important and relevant information while facilitating the implementation of content exploration strategies. On a website, structural and formatting elements contribute to the formation of perceptual groupings that guide the visual search for information through a scanning strategy (Léger et al., 2006). Consequently, their facilitating effects on the visual structuring of web pages in terms of information retrieval may be diminished or even lost for blind users. This exploratory study analyzes the effective accessibility of three flight booking websites considered to be accessible in terms of standards by simulating the interaction conditions of blind users in order to study the impact of the non-transcription of visual cues on the completion of a booking task.
2. METHOD AND MATERIALS
Currently, accessibility can be assessed using automated tools that check web pages for WCAG 2.0 compliance. However, these automated tools should not replace real human expertise (AccessiWeb, 2014) because their assessment of certain criteria remains limited (e.g., judging the adequacy of a textual alternative to an image) and, above all, they do not identify elements related to effective accessibility. Given our study objectives, we first verified the compliance of our corpus with level AA of WCAG 2.0 (W3C, 2013) and RGAA, the French general accessibility framework for government agencies (SGMAP, 2016). Once this prerequisite had been validated, we used the ergonomic inspection method, applying ergonomic criteria (Bastien et al., 1993) to analyze the effective accessibility of the booking process for blind users. This interface analysis method makes it possible to identify ergonomic flaws in an interface based on a list of defined heuristics. The choice of this method is justified by the combined application of accessibility standards and ergonomic heuristics.
After learning how to navigate using the keyboard and assistive tools, we used the JAWS screen reader and Firefox web browser, which are the screen reader and browser most commonly used on a daily basis by blind users (Atalan, 2015). The booking processes on the Air France website (http://www.airfrance.fr/) and the Voyages SNCF (http://www.voyages-sncf.com/) and Ouigo (http://www.ouigo.com/) websites are the subject of our study, in order to verify their normative accessibility, effective accessibility, and also the consistency of the booking processes so that our study subjects are similar in terms of subtasks.
3. RESULTS
3.1. Consistent user journeys and page structure
It appears that the steps in the booking process are consistent across all three sites, namely: 1) Search, 2) Search results, 3) Summary, 4) Selection of options/seats, 5) Contact details, 6) Payment. The organization of the user journey is also virtually identical across the sites, except for SNCF, which displays travel options on the search results page, while the other sites have a separate page for this, as indicated by the arrow in Figure 1. Users follow the same journey to achieve their goals.
The pages also have a similar structure depending on the different stages of the booking process. The search pages feature input fields structured on one or two lines. The results pages present the various travel options to the user in the form of lists, tabs allowing them to switch to the days before or after the travel dates, and a search summary area. The summary pages outline the trip in a list format and include an area with fare details. The options pages are also presented in the form of inserts with checkboxes, except for the Voyages SNCF site, which integrates these options into the results page, impacting its structure. The contact information pages distribute the input fields vertically. Finally, the payment pages are organized into two columns with a completion area and a summary area.
3.2. Accessible content
As the sites comply with WCAG 2.0 standards, the positive points are consistently found across the different pages. A previous study (Web AIM, 2013) showed that the main accessibility issues concerned ambiguous links and buttons, labels that were incorrectly associated with form fields, and the absence of alternative text for images or visual elements. However, demonstrating compliance with current standards, the three websites studied do not reveal these shortcomings. Links and buttons are very explicit about their destinations. Completing input fields is made easier by autocomplete, explicit labels are well associated, and thecombo box format also offers effective completion alternatives. In addition, the nature and status of the interactive elements are clearly specified, making them easy to use. The Ouigo website appears to be the easiest to use and goes somewhat beyond accessibility standards, for example, by allowing travel dates to be entered manually, without opening a dynamic calendar, but with a clearly specified completion format. However, these compliant elements do not guarantee their effective accessibility.
3.3. Non-accessible usability
Except on OUIGO, dynamic calendars for entering travel dates pose problems in terms of effective accessibility. On Voyages SNCF, the semantics of the calendar labels do not indicate that these are the travel dates to be entered (Figure 2). The only visual clue to understanding this implicit semantics is the calendar pictogram. The only way to fill in the fields is therefore to enter the dates manually, but since there is no guidance on the format, the risk of error is very high. The Air France calendar is accessible but complex to navigate using the keyboard. On the flight results page, the absence of sorting, filters, and skip links forces users to consult each piece of information because accessibility standards do not transcribe the different levels of reading. This page contains formatting elements (color of schedules, prices, etc.) that prioritize information according to its level of relevance. Without transcription of these visual properties, the information is at the same reading level and difficult to distinguish. With regard to error handling, the nature of the error is specified, but there is no automatic redirection to the fields containing errors, which suggests difficulties with self-correction. The two-column page structure, which includes booking summaries, creates redundancy that makes navigation and information consultation cumbersome. Thus, normative accessibility allows for consultation but does not facilitate the processing or manipulation of information, which effective accessibility would improve by transcribing visual cues.
4. DISCUSSION AND OUTLOOK
This exploratory study provided an initial assessment of the impact of accessibility standards in terms of their contribution to and limitations in the use of transport ticket booking interfaces. As part of a thesis on the accessibility of airline ticket booking interfaces, this study provides initial data to be verified/enriched through user testing. This work has enabled us to familiarize ourselves with how blind users navigate using assistive tools, but also to develop theoretical hypotheses for further exploration. We plan to observe blind people in situ as they perform the task of booking airline tickets across a larger sample of websites. The expected results of this research are intended not only to inform accessibility standards but also to advance best practices in design. Improving effective accessibility requires analyzing the needs of blind users, but also studying the visual cues that guide and facilitate user understanding during the booking process. Analysis of the physical layout of pages (Schmid, 2001), based on the textual architecture model (Virbel, 1989) and the language of page images (Luc, Mojahid, and Virbel, 2001) could enable the restoration of these cues so that blind users can visualize the structure of the pages and improve their understanding.
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