IIIF Viewer UX and Accessibility
Last updated
Last updated
In the context of GLAM (Galleries, Libraries, Archives, and Museums) websites, an item viewer is a key tool for providing access to digitized historical collections and archival materials. The accessibility and usability of an item viewer are crucial for ensuring inclusive access and enabling all users, including those with disabilities, to effectively interact with and utilize the valuable digital resources.
By conducting comprehensive usability and accessibility research on Mirador viewer, consulting industry partners such as Digirati and NYU Library's DLTS Team, and reviewing W3 Guidelines for "Making Content Usable for People with Cognitive and Learning Disabilities", CRKN has compiled general recommendations for ensuring good usability and accessibility of item viewers, outlined below. Expand each recommendation to view supporting information and implementation tips.
CRKN members include 85 institutions across Canada spanning world-class academic, public, and national libraries as well as research institutions. Our members support open access of Canadian heritage through our Canadiana Access Platform.
Two of our most important access collections are Canadiana which includes digitized historical publications, and Héritage, which features handwritten archival materials and is a collaboration between CRKN and Library and Archives Canada (LAC.)
As part of a mandate of adopting and contributing to open-source, community developed, software, CRKN is switching to the International Image Interoperability Framework (IIIF) as our central data model for our holdings. IIIF is a central to our plan of simplifying our infrastructure, leading to features for better supporting alternative access methods. The switch to a IIIF data model for our access objects allows CRKN to take advantage of existing software to replace in-house developed solutions.
As part of this transition, CRKN elected to replace their custom image viewing solution with an open-source community developed solution, Mirador Viewer.
To assess the accessibility and usability of the Mirador Viewer, an open-source community-developed document viewer, for Canadiana users with different accessibility needs, including those with cognitive and physical disabilities. The goal is to identify specific issues and gaps in the base Mirador code that need to be addressed to improve the accessibility and user experience for a diverse set of users.
The study aims to capture detailed feedback from an accessibility user panel, consisting of individuals with a range of disabilities, as well as a panel of existing Canadiana users, on their ability to perform key tasks in the Mirador Viewer. The findings will be used to inform specific actionable tasks and GitHub issues to be addressed by the Mirador development community, as well as configuration changes that CRKN can make to improve the accessibility and usability of the viewer. A set of generalized recommendations for digital object viewers will also be outlined, with collaboration with other GLAM community members, for the broader benefit of all GLAM institutions.
CRKN partnered with Access Changes Everything Inc. (ACE) to recruit a panel of test users with different accessibility needs, including persons with both cognitive and physical disabilities.
Next, we created a brief, simple survey that Canadiana users could complete in their first few minutes of accessing the site, that would garner CRKN basic information about who Canadiana researchers are and where their interests lie, as well as email addresses for follow-up studies.
The survey was launched in late November 2023 as a pop-up on the Canadiana site, using Survey Monkey. The survey was available in both English and French, and these translations were automatically presented on the English and French sides of the Canadiana site respectively.
The survey consisted of the following three questions:
Please tell us about yourself. I am a... (select all that apply)
Genealogical researcher
GLAM professional
Government employee
Legal researcher
Member of the general public
Post-secondary researcher
Student
Teacher
Other (please describe)
What field(s) of research are you most interested in? (select all that apply)
Computer science
Digital Humanities
Education
Environment/Climate
Gender Studies
Genealogy
Geography
Health
History
Indigenous Land Claims
Indigenous Studies
Information Science
Law
Linguistics
Literature
Political Science
Other (please specify)
Thank you for taking the survey! Are you interested in helping us improve Canadiana through focus groups and/or feature testing? Please input your email here. You can also reach out to us at info@crkn.ca
The survey had a consistently high response rate throughout the time it was open. The English translation of the survey received a gross total of 11,924 responses, and the French translation received a gross total of 1,306 responses.
Over a four hundred respondents elected to send us their contact information for UX testing.
The first step in our adoption of Mirador was to assess its current accessibility level.
To get a correct judgement of what work needed to be done to the Mirador base-code for improving accessibility, we set up an instance that was as close as possible to the Mirador 3 default settings for a single window. You can see the configuration options for the Mirador 3 viewer used in the test here.
On this version of our Mirador instance (see image below) we had the ACE accessibility user panel test the interface, and report back any issues they had while performing a robust set of tasks.
The panel of users who tested Mirador viewer included the following:
An auditor, who is fully blind, and used Windows 10 using JAWS 2024 Home Edition on EDGE browser.
An auditor, who is Deaf-Blind, and used iPad Pro 9th generation with iPadOS 17.2 with Focus 40 Blue 4th generation braille display and VoiceOver using Safari.
An auditor, almost fully blind, and used iPhone 14 Pro, using iOS 17.2 Safari browser and VoiceOver screen reader.
An auditor, who has ADHD, and used MacBook Air M2 (2022) using Safari version 16.5 with no other technology.
An auditor, who is fully blind, and used iPhone 14, OS 17.1.2, Safari and VoiceOver screen reader.
An auditor, who is Deaf-Blind, and used iPhone 13 Pro Max with iOS 17.2 using the Focus 14 Blue 4th generation and VoiceOver with Safari.
An auditor, who is almost fully blind, and used Windows 10 with Windows Narrator on EDGE.
An auditor, who has low vision, and used Apple Mac Mini (M1, 2020) running MacOS 13.4.1(c) using Safari, with 27” external monitor. Increased display contrast is on, and output is set at 1280 by 720 px. Increased zoom employed when needed.
An auditor, who is Deaf-Blind, and used Windows 11 laptop using JAWS 2020, and PacMate 20 braille display with Chrome.
An auditor, who is almost fully blind, and used Windows 10, using NVDA 2022.4 on Chrome browser Version 107.0.5304.110.
An auditor, who is Deaf-Blind, and used Windows 10 with JAWS 2019 and Focus 14 braille display with Chrome.
Raw feedback from each auditor was captured and grouped into clusters representing the specific area of the user interface it pertained to.
This was an activity which would aid us in developing specific actionable tasks to address accessibility concerns.
Based on the clusters created, twelve issues were opened in the Mirador GitHub Repository, as these issues would need to be resolved by base-code changed to Mirador.
#3877 - Icons for various functions not indicative of purpose of function
#3878 - Jarring content shift when toggling sidebar
#3879 - Mirador incompatible with JAWS 2019 (Needs Confirmation)
#3880 - Navigation between menus and tabs difficult for users with screen readers
#3881 - Screen readers do not indicate an image is displayed in OpenSeadragon canvas area
#3882 - Not enough screen reader feedback when selecting an image from sidebar lists
#3883 - Not enough screen reader feedback when toggling sidebar
#3884 - Screen readers do not announce the selection of images in the side menu
#3885 - Screen readers do not announce effects of zoom buttons
#3886 - Current image index and number of images is not clear for users with screen readers
Additionally, five observations were made relating to plugins or settings in Mirador, which could be changed directly by CRKN to provide a more accessible experience. Expand the sections below to see the supporting information for the corresponding observation.
Fixes were applied to address the five accessibility issues listed above, that could be remediated through Mirador configuration options and settings, as outlined below.
Users had significant difficulty using the download functionalities.
Searchable PDF versions of our items have been determined to be the best mode of access for people with assistive technology. (It is recommended that we prioritize OCR of all content in our access platforms.)
The PDF version of the item was changed from a pdf button at the bottom of the viewer to a ‘Download Searchable PDF (size)’ button directly after the title of the item. Additionally, for users with screen readers, the following text will be read aloud to them, after this button: ‘Downloading the searchable PDF is the recommended mode of access for people using assistive technologies.’
All reference to ‘images’ occurs after this point – it was not clear to the users that this was an image viewer, so effort was made to change labelling and group functions references images into the main viewer.
A new plugin was created to allow the user to download the current image as a jpeg, or searchable PDF. Upon clicking the respective files are downloaded.
Other resolution options were also added to this menu via the open source mirador downloads plugin.
Finally, the open-source PDIIIF plugin was added to the ‘...’ menu labelled as ‘Print Images to PDF.’ This was kept separate from the single image downloads since it can be used for the entire document. Effort was made to make it clear to the user that the resulting PDF will not be searchable. Locating this print option in the ‘...’ menu follows standard navigational practices for software.
The thumbnail list provided an uneven experience to users depending on their accessibility needs
It was found that the canvas list tab on the left-side of the default mirador layout was redundant and caused the users to have to tab through the canvas list before interacting with any following content.
The left-side menu was edited to only include information about the item – the canvas list was completely removed from the UI on the left-side.
Users can enable thumbnail list navigation through the ‘Window views and thumbnail display’ menu option. It is kept off by default to better support keyboard navigation.
The previous and next buttons are the preferred mechanism to use as primary navigation.
Users can enable thumbnail list navigation through the ‘Window views and thumbnail display’ menu option. It is kept off by default to better support keyboard navigation.
Removed canvas listing from the left side menu, which removes a lot of keyboard tabbing before being able to interact with the previous and next buttons.
The 'resource' label in the information side panel can be confusing for those with screen readers.
It was found that the info section labels made the viewing experience confusing. Labels were changed:
‘Current Item’ has become ‘Current Image’
‘Resource’ has become ‘Item Title’
These changes also further indicate the nature of the viewer as an image viewer showing the images related to a historical item.
Triggering zooming in the image display through the mouse wheel scrolling and finger scrolling led to frustration, as users needed to access page elements below the image display.
It was found that zooming on scrolling over the viewer was an accessibility concern, as well as a UX concern for accessing content below the viewer. Therefore, we disabled zoom on scroll for the viewer.
These changes resulted in the following design for a 'more accessible' version of Mirador. You can see the configuration options for the Mirador 3 viewer used in the test here.
To determine any general usability issues with the 'more accessible' design shown above, and to ensure that introducing this new viewer would be seen as a positive change by our existing users, CRKN held unmoderated usability sessions using Maze on the 'more accessible' design.
The usability tests included the following ten tasks, which were to be completed within a 30-minute session.
Navigate to the second image of the document.
Zoom into the second image and read a specific paragraph.
Locate a list of contributors or authors for the item.
View all the images at once in a gallery view.
Navigate to the 33rd image.
Search for the word ‘bee’ in the text and record the full sentence of the third search result.
Download the entire document in a single PDF.
Try printing only images 1, and 4 through 6 as a PDF.
Edit the brightness of the image.
Turn on the thumbnail list navigation feature.
For each of these tasks, Maze allowed us to configure the expected path a user should have taken to complete the task successfully. Maze tracked inputs and mouse movements, missed clicks, heatmaps, etc. Maze also kept recordings wherein we will ask the participant to talk aloud as they work on a task. For each task, Maze collected the following KPIs: success rate, time-on-task, and user error rate.
We had thirty-three participants in total who successfully completed the study.
The following System Usability Score (SUS) was calculated for the 'more accessible' version of Mirador: 70.25. A SUS score above a 68 would be considered above average and anything below 68 is below average. Therefore, the SUS score was found to be average for the mostly ‘vanilla’ Mirador viewer with the settings changes applied, with a confidence level of 2/3 according to Maze.io. A higher confidence level could be attained by receiving 100 or more responses.
Through analyzing the recordings of each test participant, taking note of what was said aloud as well as mouse movements, the following observations and suggested remediations were developed. A severity level was assigned to each pain-point based on the number of users who had difficulties completing the task, and the level of confusion indicated by each individual test user when completing the task.
Users had trouble locating the Gallery view (Severity 3)
The single and gallery views were retained, but the functionality to toggle between the views was added to the main toolbar menu, rather than hidden in a drop-down menu.
Users expressed the desire for a quick (and accessible) way to nav through images that is always visible (Severity 3)
A Mirador plugin was implemented to re-introduce a drop-down menu for quick image selection, additionally offering a search functionality to reduce the number of options displayed to the user for selection.
Added go to first and go to last buttons.
Users had difficulty noticing the next and previous buttons (Severity 2)
Used bolder and bigger next and previous buttons and grouped navigational buttons to the left-hand side of the toolbar for users to notice them more quickly.
Users often went to the 'current image download' menu first when asked to download manifest as PDF (Severity 2)
For users taking advantage of screen readers, keep the download searchable pdf and note about this being the best experience for screen readers visible. For all other users, hide this link to reduce the number of download icons on the page.
Tooltips do not render on tablet and mobile (Severity 2)
Modifications were made so that tooltip text is utilized less for explanatory information. Tooltips require hover functionality, and as many users access websites through tablets and mobile devices, where the hover function is not available, the benefit of tooltips is void. Efforts will be made to select clear icons or use text labels where needed.
Users are unsure if PDIIIF downloads completed (Severity 2)
The PDIIIF plugin was enhanced for better confirmation of download, as it was not clear that the file has been created for the user when the progress bar reached 100%.
Thumbnail display is not desired in comparison to Gallery, remove to reduce viewer complexity (Severity 1)
The thumbnail strip navigation will be removed to reduce the number of options displayed to the user, as the same functionality is obtained in the gallery view, which was a more desired feature to our end users than a thumbnail strip.
The info panel showed redundant information, but took up space, and added more links and buttons for the users to search through, when looking for a specific functionality. (Severity 1)
To save space on the screen the info sidebar was removed, in preference for this information showing below the viewer.
The changes outlined above resulted in the following design for the CRKN Mirador viewer. You can see the code for this Mirador viewer here. Code for plugins used by the viewer are accessible here.
For discovery of pain-points, it was found that the analysis of screen recordings and verbal output of test users was most useful. This was for multiple reasons. Test users often explored unrelated areas of the interface during a specific task, which would skew the recorded 'average time on task' KPI collected by Maze. Additionally, mouse movements were found to be very helpful in understanding where our users thought a specific functionality might be. By analyzing the recordings manually, we could develop a more accurate understanding of the experience of our users.
One enhancement that could be made to future studies is putting an emphasis on staying on-task during the usability test, to ensure automated heat maps and KPIs remain more useful for analysis.
This version of the CRKN Mirador viewer will be included in open beta testing of our new access platform as we head into Q4 of 2024. Further feedback will be gathered from end users and stakeholders via this open beta testing. CRKN will also work towards ensuring the full suite of recommendations outlined are implemented in our viewer.
GLAMs are known for their digital innovation, yet many, especially smaller institutions, face challenges in making their online services user friendly and accessible because of limited budgets, resources, and in-house expertise. Pooling our resources and expertise to enhance the accessibility and UX of IIIF software will make it easier for all users to explore our digital collections. Advocacy for accessibility and UX within the community is another important factor that will lead to the prioritization of much needed enhancements.
Through the Mirador Community Calls, CRKN presented the findings of our accessibility and usability tests to the Mirador Group. This group included people from Harvard, Stanford, NYU, Universität Leipzig and more. Since CRKN tested Mirador version 3, there was some discussion about how to confirm that the issues we opened would still be relevant in version 4, with NYU volunteering to verify the issues are still present in Mirador version 4.
The Mirador repository also included additional UX and Accessibility issues that were not created by CRKN as a result of this study. To address the issues created by CRKN as well as existing issues, an 'Accessibility + UX' project was created on GitHub.
CRKN and NYU are processing the related issues into actionable development tickets, and populating the project. Development time will be allotted to the issues within the project upon final release of Mirador version 4. CRKN has also received access to contribute to Mirador Base code on GitHub.