Minimum Digital Accessibility Standards

The Minimum Digital Accessibility Standards (MDAS) form the technical implementation standards of Ohio State’s Digital Accessibility Policy. Maintained by the Digital Accessibility Center under the direction of the ADA Coordinator’s Office, the MDAS were originally adopted in 2004 as the Minimum Web Accessibility Standards then updated, expanded, and renamed in 2017. The goal of MDAS is to ensure that digital information and services provided by the university are functionally accessible to persons with disabilities.

According to Ohio State’s Digital Accessibility Policy, all digital information and services to be used by faculty, staff, program participants, the general public, or other university constituencies are required to be compliant with the non-discrimination provisions of the Americans with Disabilities Act (ADA), as amended, and Section 504 of the Rehabilitation Act. This document provides elaboration and testable standards to help OSU technologists and purchasing agents meet their policy obligations.

To be compliant with our Digital Accessibility Policy, a person with a disability must be afforded the opportunity to acquire the same information, engage in the same interactions, and enjoy the same services as a person without a disability in an equally effective and equally integrated manner, with substantially equivalent ease of use. A person with a disability must be able to obtain the information or service as fully, equally, and independently as a person without a disability.

To satisfy the requirement to comply with the ADA and meet the Minimum Digital Accessibility Standards, digital information and services should be designed to be functionally accessible, rather than merely technically accessible. While technical accessibility determines whether a resource is coded to an accepted accessibility standard, to be functionally accessible means that any person can use the resource effectively to perform an available task. Coding to an accepted standard is often a means of approaching functional accessibility, but achieving functional accessibility means that resources are easy to use and content is clear and unambiguous for all users, regardless of ability.

To be functionally accessible, digital information and services must consider use by people who may:

  • have severe or moderate visual impairment
  • be colorblind
  • be deaf or hard of hearing
  • have motor disabilities
  • have cognitive disabilities

Users with severe visual impairments typically use screen readers, programs that render text and image content as speech or braille output to assist with the navigation of web pages and other programs. Screen readers identify not only text, but also alternate text added to provide a description for images. They facilitate full interaction with web page content and allow users to skip between chunks of content by link, heading, form element, and content area, among other means. Invalid or lax coding practices, minimal logical structure and semantics, and inappropriate or missing textual descriptions for images or links make navigation and understanding of web content difficult or impossible for screen reader reliant users. Some uses of dynamic content or plug-ins can be inaccessible to screen readers as well.

The screen readers most commonly used at Ohio State are Freedom Scientific’s JAWS for Windows followed by NVDA from NV Access, though there is also significant use of VoiceOver, the screen reader on Apple Mac and iOS devices. Because of the variety of screen readers in use on campus, testing on more than one platform, including mobile, is strongly recommended. NVDA is a free screen reader for Windows which tends to be in the vanguard in its handling of modern web page/application implementations. The university recommends it for testing, along with VoiceOver on Mac and iOS.

Users with moderate to severe visual impairments (“low vision”) typically enlarge their on-screen fonts, either by using the browser’s zoom or text scaling facilities or by using screen magnification software. These users may also set their operating system to a “high-contrast” mode or use custom style sheets to increase the contrast between foreground text and background colors.

Users with color blindness have problems distinguishing between certain colors. Digital information and services must not use color as the sole means of conveying information to ensure that users who cannot perceive color differences are able to understand the content.

Users who are deaf or hard of hearing may rely on transcripts of audio content, captioned video, and alternatives to auditory cuing.

According to best practices and our Minimum Digital Accessibility Standards, all video content must have a synchronized text track (captions), providing transcription of spoken text, speaker identification, and text equivalents of non-verbal audio (a.k.a., sound effects), as appropriate. Audio podcasts and other spoken audio must be accompanied by a full text transcription. Web pages or applications that use audio cues also should provide a visual, preferably text-based, cue.

Users with various motor disabilities may have difficulty using a mouse or track pad as a pointing device, due to nerve conditions, disease, or injury. Limited motor acuity may affect response times and accuracy in selecting navigation or options within forms and other controls. Repetitive stress and other less severe motor disabilities may make over-reliance on the keyboard difficult – for example, excessive tabbing to move through controls. Users with limited upper-body mobility may use speech recognition for input or other input devices which mimic keyboard input, or they may rely solely on the keyboard for all input.

Developers should test to make sure all navigation, forms, and other control elements in web pages and application interfaces are accessible and operable via the keyboard alone, and ensure that if timed responses are necessary there is the ability to extend the time, and that that functionality is easy to understand and locate in the page or application. Also try to judge the impact on usability afforded by the quantity and complexity of input required for navigation, form, or other input. The university also recommends testing the usability of web forms and applications with speech recognition software, such as Dragon Naturally Speaking or Windows Speech Recognition.

Cognitive disability is the most broad and varied category of disability. Most users with disabilities registered through our Office of Student Life Disability Services have some form of cognitive disability. Thus, attention to usability problems that may be encountered by users with cognitive disabilities will have proportionally the greatest positive impact on consumers of digital information and services. Cognitive disabilities include conditions affecting reading and verbal comprehension, learning disabilities, attention and distractibility disorders, conditions affecting memory and processing of large amounts of information, and problems comprehending information presented mathematically or graphically.

Try to assess the general usability and comprehensibility – clarity in presentation and logical and spatial organization – of digital resources. Ensuring correct grammar and spelling and reducing verbal complexity will have a positive impact for users with certain cognitive disabilities, as well.

The Ohio State Minimum Digital Accessibility Standards directly adopt the following standards and guidelines, with clarifications and amendments as noted below.

Clarifications and Amendments

The following clarifications and amendments apply to the preceding standards within the scope of the MDAS:

  • WCAG 2.1
    • Success Criterion 1.2.5 Audio Description (Prerecorded) is not required for conformance.
      Note that Success Criterion 1.2.3 still applies, which requires a transcript for prerecorded media if an audio description track is not provided.
    • Success Criterion 1.4.11 Non-text Contrast applies to focus indicators used to satisfy Success Criterion 2.4.7 Focus Visible if the document overrides default browser styles.


  • September 1, 2021: WCAG version 2.1 adopted, clarifications and amendments section added. MDAS v1 retired.
  • June 22, 2020: WAI-ARIA Authoring Practices 1.1 adopted
  • May 5, 2017: Minimum Web Accessibility Standards renamed Minimum Digital Accessibility Standards with expanded scope and updated standards. WCAG 2.0 and WCAG2ICT adopted.
  • 2013: MWAS updated with new standards and recommendations
  • 2004: Minimum Web Accessibility Standards created

Previous versions of Ohio State’s technical standards for digital accessibility can be found below: