What is Usability? A Characterization based on ISO 9241-11 and ISO/IEC 25010

According to Brooke* "Usability does not exist in any absolute sense; it can only be defined with reference to particular contexts." That is, one cannot speak of usability without specifying what that particular usability is characterized by. Driven by the feedback of a reviewer at an international conference, I explore in which way one can precisely specify the kind of usability they are investigating in a given setting. Finally, I come up with a formalism that defines usability as a quintuple comprising the elements level of usability metrics, product, users, goals and context of use. Providing concrete values for these elements then constitutes the investigated type of usability. The use of this formalism is demonstrated in two case studies. * J. Brooke. SUS: A "quick and dirty" usability scale. In P. W. Jordan, B. Thomas, B. A. Weerdmeester, and A. L. McClelland, editors, Usability Evaluation in Industry. Taylor and Francis, 1996.Comment: Technical Report; Department of Computer Science, Technische Universit\"at Chemnitz; also available from https://www.tu-chemnitz.de/informatik/service/ib/2015.php.e

EXPLORING THE STAGES OF INFORMATION SEEKING IN A CROSS-MODAL CONTEXT

Previous studies of users with visual impairments access to the web have focused on human-web interaction. This study explores the under investigated area of cross-modal collaborative information seeking (CCIS), that is, the challenges and opportunities that exist in supporting visually impaired (VI) users to take an effective part in collaborative web search tasks with sighted peers. We conducted an observational study to investigate the process with fourteen pairs of VI and sighted users in co-located and distributed settings. The study examined the effects of cross-modal collaborative interaction on the stages of the individual Information Seeking (IS) process. The findings showed that the different stages of the process were performed individually most of the time; however it was observed that some collaboration took place in the results exploration and management stages. The accessibility challenges faced by VI users affected their individual and collaborative interaction and also enforced certain points of collaboration. The paper concludes with some recommendations towards improving the accessibility of cross-modal collaborative search.Peer Reviewe

Using Digital Libraries Non-Visually: Understanding the Help-Seeking Situations of Blind Users

Introduction. This study explores blind users\u27 unique help-seeking situations in interacting with digital libraries. In particular, help-seeking situations were investigated at both the physical and cognitive levels. Method. Fifteen blind participants performed three search tasks, including known-item search, specific information search, and exploratory search, using the selected digital library. Pre-questionnaire, pre- and post-interviews, transaction logs and think-aloud protocols were used to collect data. Analysis. Open coding analysis was used to identify help-seeking situations the physical and cognitive levels. Results. The study identified seventeen help-seeking situations that blind users encountered while using digital libraries, including nine at the physical level and eight at the cognitive level. To be more specific, physical help-seeking situations were categorised into 1) difficulty accessing information, 2) difficulty identifying current status and path, and 3) difficulty evaluating information efficiently. Cognitive help-seeking situations were classified into 1) confusion about multiple programs and structures, 2) difficulty understanding information, 3) difficulty understanding or using digital library features, and 4) avoidance of specific formats or approaches. Conclusion. The identified help-seeking situations reveal a gap between current digital library design practices and special needs of blind users. Practical implications for the design of help features for more blind-friendly digital libraries are suggested based on the findings

Designing Search User Interfaces for Visually Impaired Searchers: A User-centred Approach

PhDThe Web has been a blessing for visually impaired users as with the help of assistive technologies such as screen readers, they can access previously inaccessible information independently. However, for screen reader users, web-based information seeking can still be challenging as web pages are mainly designed for visual interaction. This affects visually impaired users’ perception of theWeb as an information space as well as their experience of search interfaces. The aim of this thesis is therefore to consider visually impaired users’ information seeking behaviour, abilities and interactions via screen readers in the design of a search interface to support complex information seeking. We first conduct a review of how visually impaired users navigate the Web using screen readers. We highlight the strategies employed, the challenges encountered and the solutions to enhance web navigation through screen readers. We then investigate the information seeking behaviour of visually impaired users on the Web through an observational study and we compare this behaviour to that of sighted users to examine the impact of screen reader interaction on the information seeking process. To engage visually impaired users in the design process, we propose and evaluate a novel participatory approach based on a narrative scenario and a dialogue-led interaction to verify user requirements and to brainstorm design ideas. The development of the search interface is informed by the requirements gathered from the observational study and is supported through the inclusion of visually impaired users in the design process. We implement and evaluate the proposed search interface with novel features to support visually impaired users for complex information seeking. This thesis shows that considerations for information seeking behaviour and users’ abilities and mode of interaction contribute significantly to the design of search user interfaces to ensure that interface components are accessible as well as usable

What Is Known About the Impact of Impairments on Information Seeking and Searching?

Information seeking and access are essential for users in all walks of life, from addressing personal needs such as finding flights to locating information needed to complete work tasks. Over the past decade or so, the general needs of people with impairments have increasingly been recognized as something to be addressed, an issue embedded both in international treaties and in state legislation. The same tendency can be found in research, where a growing number of user studies including people with impairments have been conducted. The purpose of these studies is typically to uncover potential barriers for access to information, especially in the context of inaccessible search user interfaces. This literature review provides an overview of research on the information seeking and searching of users with impairments. The aim is to provide an overview to both researchers and practitioners who work with any of the user groups identified. Some diagnoses are relatively well represented in the literature (for instance, visual impairment), but there is very little work in other areas (for instance, autism) and in some cases no work at all (for instance, aphasia). Gaps are identified in the research, and suggestions are made regarding areas where further research is needed

Interactive audio-tactile maps for visually impaired people

International audienceVisually impaired people face important challenges related to orientation and mobility. Indeed, 56% of visually impaired people in France declared having problems concerning autonomous mobility. These problems often mean that visually impaired people travel less, which influences their personal and professional life and can lead to exclusion from society. Therefore this issue presents a social challenge as well as an important research area. Accessible geographic maps are helpful for acquiring knowledge about a city's or neighborhood's configuration, as well as selecting a route to reach a destination. Traditionally, raised-line paper maps with braille text have been used. These maps have proved to be efficient for the acquisition of spatial knowledge by visually impaired people. Yet, these maps possess significant limitations. For instance, due to the specificities of the tactile sense only a limited amount of information can be displayed on a single map, which dramatically increases the number of maps that are needed. For the same reason, it is difficult to represent specific information such as distances. Finally, braille labels are used for textual descriptions but only a small percentage of the visually impaired population reads braille. In France 15% of blind people are braille readers and only 10% can read and write. In the United States, fewer than 10% of the legally blind people are braille readers and only 10% of blind children actually learn braille. Recent technological advances have enabled the design of interactive maps with the aim to overcome these limitations. Indeed, interactive maps have the potential to provide a broad spectrum of the population with spatial knowledge, irrespective of age, impairment, skill level, or other factors. To this regard, they might be an efficient means for providing visually impaired people with access to geospatial information. In this paper we give an overview of our research on making geographic maps accessible to visually impaired people