Automatic Accessibility Validation and Monitoring of Public Administration Web Sites

Agenzia per l’Italia Digitale (Agid) and the Institute of Information Science and Technologies "Alessandro Faedo" of the National Research Council of Italy (CNR-ISTI) have signed an agreement for the development of a system aimed at automatically monitoring the accessibility of websites of the Italian Public Administrations. The collaboration aims to contribute to the implementation of measure 1.4.2 of the PNRR, focused on improving the accessibility of digital services provided to the public. The agreement supports the evolution of the MAUVE ++ platform in order to provide public administrations with a system free of charge aimed at automatically verifying the accessibility of their sites.

The importance of providing accessible Web applications for all, including people with cognitive or physical disabilities, has become increasingly recognised. This is confirmed by the indications provided by national and international legislations to support it. A major initiative to address such aspects is the EU Directive on the “Accessibility of the Websites and Mobile Applications of Public Sector Bodies” that came into force on 26/10/2016, also known as the Web Accessibility Directive (WAD), which establishes accessibility requirements for the websites and mobile applications of public sector bodies. One aspect that is particularly stimulated by this directive is monitoring, which should be done more systematically in terms of the number of Web pages involved, and with some level of frequency.

In parallel, the guidelines for accessibility of Web Sites, which are developed by W3C in the Web Accessibility Initiative, are continuously evolving considering the need for better addressing the various possible disabilities and the evolution of Web Technologies. The current version (2.1) is structured into principles, guidelines, success criteria, and techniques, which have increased with respect to the previous versions.

All such aspects imply that thorough accessibility validation requires considerable effort for the number of elements and aspects that have to be checked. Thus, the interest in automatic support for this activity is continuously increasing, and stimulates further research and development in this area because of its potential to support the collection and analyses of data on the effective application of the accessibility guidelines, detect non-compliance in a consistent manner, and provide relevant information on how to address possible problems. At the same time, it is important to be aware that not all accessibility issues can be automatically detected, some of them require manual checking from accessibility experts, and subjective feedback is still important to consider.

The CNR-ISTI laboratory that works in the project is the one on Human Interfaces in Information Systems (HIIS), which has among its founding working areas that of tools for supporting the evaluation of accessibility and usability, and in the course over the years it has developed numerous studies and systems in this area. The last one is MAUVE ++, which addresses three emerging important aspects: accessibility monitoring, tool transparency, and support for dynamic Web sites. The first means the ability to indicate a set of Web pages and periodically check the level of accessibility in order to inform relevant stakeholders about how it evolves. The second aims to address one important problem that users of automatic validators often encounter when using multiple tools: they may provide different results. Users of such tools are often disoriented by such differences, and find them somewhat unclear. Thus, it becomes important that the tools be transparent and indicate in detail what they are actually able to validate. The last aspect aims to address the increasing use of development frameworks that implement dynamic Web sites, such as Angular or Vue.js.

In June 2022, our MAUVE++ tool has carried out the accessibility validation of 10557 web sites of public organizations for a total of 1971514 pages, with average accessibility of 92% (Number of elements successfully evaluated out of the total number of elements for which the tool was able to make a successful or unsuccessful evaluation), and completeness of 90% (which means that 10% checks of the page elements should be completed manually). Most frequent failed criteria and techniques were (in order of frequency starting with the most frequent):

1.4.11 - 1.4.3,"G18" - Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text
1.4.11,"G195" - Using an author-supplied, highly visible focus indicator
1.4.4 - 1.4.5,"C12-13-14" - Using percent, em units or named font sizes
1.4.10,"SCR34" - Calculating size and position in a way that scales with text size
1.4.11 - 2.4.7,"F78" - Failure due to styling element outlines and borders in a way that removes or renders non- visible the visual focus indicator
1.3.1 - 1.4.5,"G140" - Separating information and structure from presentation to enable different presentations
2.4.4 - 1.1.1,"H30" - Providing link text that describes the purpose of a link for anchor elements
1.3.1,"H42" - Using h1-h6 to identify headings
1.4.13,"1.4.13-ST2" - CSS: Using hover and focus pseudo classes
4.1.1,"H93" - Ensuring that id attributes are unique on a webpage
1.3.5,"H98" - Identify the purpose of inputs using the autocomplete value
1.4.10,"C38" - Using CSS width, max-width and flexbox to fit labels and inputs

Another large scale evaluation is in progress its results will be made publicly available through a dashboard at Agid at the end of March 2023

More info on the MAUVE++ tool in the paper Usability and transparency in the design of a tool for automatic support for web accessibility validation on the Universal Access in the Information Society journal by N.Iannuzzi, M.Manca, F.Paternò, C.Santoro

Project Coordinator: Fabio Paternò, fabio.paterno at

MAUVE++ Accessibility Evaluation Summary of a Web Page