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This work aims to argue that it is possible to address discrimination issues that naturally arise in contemporary audio CAPTCHA challenges and potentially enhance the effectiveness of audio CAPTCHA systems by adapting the challenges to the user characteristics.

A prototype has been designed, called PrivCAPTCHA, to offer privacy-preserving, user-centric CAPTCHA challenges. Anonymous credential proofs are integrated into the Session Initiation Protocol (SIP) protocol and the approach is evaluated in a real-world Voice over Internet Protocol (VoIP) environment.

The results of this work indicate that it is possible to create VoIP CAPTCHA services offering privacy-preserving, user-centric challenges while maintaining sufficient efficiency.

The proposed approach was evaluated through an experimental implementation to demonstrate its feasibility. Additional features, such as appropriate user interfaces and efficiency optimisations, would be useful for a commercial product. Security measures to protect the system from attacks against the SIP protocol would be useful to counteract the effects of the introduced overhead. Future research could investigate the use of this approach on non-audio CAPTCHA services.

PrivCAPTCHA is expected to achieve fairer, non-discriminating CAPTCHA services while protecting the user’s privacy. Adoption success relies upon the general need for employment of privacy-preserving practices in electronic interactions.

This approach is expected to enhance the quality of life of users, who will now receive CAPTCHA challenges closer to their characteristics. This applies especially to users with disabilities. Additionally, as a privacy-preserving service, this approach is expected to increase trust during the use of services that use it.

To the best of authors’ knowledge, this is the first comprehensive proposal for privacy-preserving CAPTCHA challenge adaptation. The proposed system aims at providing an improved CAPTCHA service that is more appropriate for and trusted by human users.

This paper aims to describe the development of a new experimental CAPTCHA (completely automated public turing test to tell computers and humans apart), which is supposed to provide better protection against spam bots compared to the existing captcha solutions.

In the new CAPTCHA, the authors are using animated images of hand gestures to represent letters and numbers. A lot of people use sign language as their primary means of communication, but an automatic algorithm able to reliably recognize such gestures from videos without any additional data has yet to be developed.

The experiment showed that at first, it takes time for people who do not use sign languages in their everyday lives to adapt to the new CAPTCHA, but after several successful recognitions, they have no more trouble with it than with a typical captcha implementation.

The paper shows that people with little to no knowledge of sign languages can still recognize gestures on video relatively fast. Therefore, a gesture-based implementation can be used not only on websites aimed at sign language speakers but also as a general-purpose captcha service.

The purpose of this research is to identify and describe the impact of comment spam in library blogs. Three research questions guided the study: current level of commenting in library blogs; librarians' perception of comment spam; and techniques used to address the comment spam problem.

A quantitative approach is used to investigate research questions. Informal interviews were conducted with four academic and three public libraries with active blogs to develop a better understanding of the problem and then to develop an appropriate data collection instrument. Based on the feedback received from these blog administrators, a survey questionnaire was developed and then distributed online via direct e‐mailing and mailing lists. A total of 108 responses were received.

Regardless of the library type with which blogs were affiliated with and the size of the community they served, user participation in library blogs was very limited in terms of comments left. Over 80 percent of libraries reported receiving five or fewer comments in a given week. Comment spam was not perceived to be a major problem by blog administrators. Detection‐based techniques were the most commonly used approaches to combat comment spam in library blogs.

The research focuses on the comment spam problem in blogs affiliated with libraries where the library is responsible for content published on the blog. The comment spam problem is investigated from the library blog administrator's perspective.

Results of this study provide empirical evidence regarding level of commenting and the impact of comment spam in library blogs. The results and findings of the study can offer guidance to libraries that are reconsidering whether to allow commenting in their blogs and to those that are planning to establish a blog to reach out to their users, while keeping this online environment engaging and interactive.

The study provides empirical evidence that level of commenting is very limited, comment spam is not regarded as an important problem, and it does not interfere with the communication process in library blogs.

Image annotation plays an important role in image retrieval process, especially when it comes to content-based image retrieval. In order to compensate the intrinsic weakness of machines in performing cognitive task of (human-like) image annotation, leveraging humans’ knowledge and abilities in the form of crowdsourcing-based annotation have gained momentum. Among various approaches for this purpose, an innovative one is integrating the annotation process into the CAPTCHA workflow. In this paper, the current state of the research works in the field and experimental efficiency analysis of this approach are investigated.

At first, and with the aim of presenting a current state report of research studies in the field, a comprehensive literature review is provided. Then, several experiments and statistical analyses are conducted to investigate how CAPTCHA-based image annotation is reliable, accurate and efficient.

In addition to study of current trends and best practices for CAPTCHA-based image annotation, the experimental results demonstrated that despite some intrinsic limitations on leveraging the CAPTCHA as a crowdsourcing platform, when the challenge, i.e. annotation task, is selected and designed appropriately, the efficiency of CAPTCHA-based image annotation can outperform traditional approaches. Nonetheless, there are several design considerations that should be taken into account when the CAPTCHA is used as an image annotation platform.

To the best of the authors’ knowledge, this is the first study to analyze different aspects of the titular topic through exploration of the literature and experimental investigation. Therefore, it is anticipated that the outcomes of this study can draw a roadmap for not only CAPTCHA-based image annotation but also CAPTCHA-mediated crowdsourcing and even image annotation.

The purpose of this paper is to explain the changes in the Web Content Accessibility Guidelines (WCAG) 2.0 compared with WCAG 1.0 within the context of its historical development.

In order to compare WCAG 2.0 with WCAG 1.0 a diachronic analysis of the evolution of these standards is done. Known authors and publications in the field, the Web Accessibility Initiative (WAI) web pages, WebAIM and the blogosphere were also monitored for comments and third‐party analyses. The analysis of the main changes from WCAG 1.0 to WCAG 2.0 was based on personal experience with WAI guidelines, experimentation with some of the new guidelines, and a selection of best practice online services in the application of the WCAG, including WAI documentation.

WCAG 2.0 is more educational and is applied to more technologies than WCAG 1.0. The limitations of WCAG 1.0 are mostly due to its origin. In changing from one to the other, new priorities and new elements must be taken into account. The paper concludes that though these guidelines are a useful tool for governments, they are only the first step towards accessibility, which can only be achieved through user‐centred design.

This paper explains the significance and limitations of the WCAG and gives a short guide to adapting web sites to the new regulations.

The purpose of this paper is to explore the task design and assignment of full-text generation on mass Chinese historical archives (CHAs) by crowdsourcing, with special attention paid to how to best divide full-text generation tasks into smaller ones assigned to crowdsourced volunteers and to improve the digitization of mass CHAs and the data-oriented processing of the digital humanities.

This paper starts from the complexities of character recognition of mass CHAs, takes Sheng Xuanhuai archives crowdsourcing project of Shanghai Library as a case study, and makes use of the theories of archival science, including diplomatics of Chinese archival documents, and the historical approach of Chinese archival traditions as the theoretical basis and analysis methods. The results are generated through the comprehensive research.

This paper points out that volunteer tasks of full-text generation include transcription, punctuation, proofreading, metadata description, segmentation, and attribute annotation in digital humanities and provides a metadata element set for volunteers to use in creating or revising metadata descriptions and also provides an attribute tag set. The two sets can be used across the humanities to construct overall observations about texts and the archives of which they are a part. Along these lines, this paper presents significant insights for application in outlining the principles, methods, activities, and procedures of crowdsourced full-text generation for mass CHAs.

This study is the first to explore and identify the effective design and allocation of tasks for crowdsourced volunteers completing full-text generation on CHAs in digital humanities.

This paper aims to present a framework to analyse whether information published on social media is accessible for people with disabilities (PwD), namely, visual and hearing disabilities, with an application to a music festival.

The methodology used in this exploratory study consists of establishing a recommended framework to assess social media accessibility for PwD, especially for people with visual and hearing disabilities (PwVHD), and analyse, through an observation grid, if the information published on the official pages of the “Rock in Rio Lisboa” music festival on Facebook, Instagram, Twitter and YouTube is accessible for this target audience.

The results indicate that, although the Rock in Rio Lisboa music festival is promoted as a festival for all, posts on social media are not accessible for people with visual and/or hearing disabilities and do not meet most of the defined parameters established in the proposed assessment framework.

Social media accessibility has not been analysed in previous research in the tourism context. This paper aims to fill in the void by establishing criteria and parameters that can serve as a basis for a framework for accessibility assessment in social media for PwVHD.

Despite the widespread use of authentication schemes and the rapid emergence of novel authentication schemes, a general set of domain-specific guidelines has not yet been developed. This paper aims to present and explain a list of human-centered guidelines for developing usable authentication schemes.

The guidelines stem from research findings within the fields of psychology, human–computer interaction and information/computer science.

Instead of viewing users as the inevitable weak point in the authentication process, this study proposes that authentication interfaces be designed to take advantage of users’ natural abilities. This approach requires that one understands how interactions with authentication interfaces can be improved and what human capabilities can be exploited. A list of six guidelines that designers ought to consider when developing a new usable authentication scheme has been presented.

This consolidated list of usable authentication guidelines provides system developers with immediate access to common design issues impacting usability. These guidelines ought to assist designers in producing more secure products in fewer costly development cycles.

Cybersecurity research and development has mainly focused on technical solutions to increase security. However, the greatest weakness of many systems is the user. It is argued that authentication schemes with poor usability are inherently insecure, as users will inadvertently weaken the security in their efforts to use the system. The study proposes that designers need to consider the human factors that impact end-user behavior. Development from this perspective will address the greatest weakness in most security systems by increasing end-user compliance.

While technologies are often packaged as solutions to long-standing social ills, scholars of digital economies have raised the alarm that, far from liberatory, technologies often further entrench social inequities and in fact automate structures of oppression. This literature has been revelatory but tends to replicate a methodological nationalism that erases global racial hierarchies. We argue that digital economies rely on colonial pathways and in turn serve to replicate a racialized and neocolonial world order. To make this case, we draw on W.E.B. Du Bois' writings on capitalism's historical development through colonization and the global color line. Drawing specifically on The World and Africa as a global historical framework of racism, we develop heuristics that make visible how colonial logics operated historically and continue to this day, thus embedding digital economies in this longer history of capitalism, colonialism, and racism. Applying a Du Boisian framework to the production and propagation of digital technologies shows how the development of such technology not only relies on preexisting racial colonial production pathways and the denial of racially and colonially rooted exploitation but also replicates these global structures further.