Methodology

The results presented on this website are based upon Siteimprove's Accessibility Digital Certainty Index™ (DCI). The accessibility DCI is a metric developed by Siteimprove to indicate the level of a website’s accessibility.

Siteimprove’s automated accessibility checks are based on techniques used to evaluate conformance to the Web Content Accessibility Guidelines (WCAG) success criteria.

The DCI Accessibility Score is a quantitative ratio value based on a combination of automatically tested properties that indicates the level of accessibility barriers identified for a given website, and therefore, is not a conformance level score.

The Algorithm

To generate a balanced metric, and to control sensitivity, Siteimprove designed an algorithm that weights several qualities of the pages across a website. The result is a singular score between one and 100. The higher the score the fewer accessibility barriers are identified.

To aid the interpretation of the score, Siteimprove have identified the following categories:

Siteimprove’s automated accessibility checks are based on the Web Content Accessibility Guidelines. The algorithm makes a distinction between errors and warnings to distinguish between failing to meet WCAG success criteria and best practices:

• Errors: automatically determined failures to meet success criteria in WCAG.
• Warnings: automatically determined failures to meet best practices in WCAG.

In addition to these two categories, the algorithm distinguishes between checks from A, AA, and AAA conformance levels. (For more information please see article: Levels A, AA, AAA errors in Siteimprove Accessibility explained.)

With the categories and levels combined, Siteimprove weighs the issues that occur on the website and reflect these using points, which in turn generates the Accessibility score.

How are Issues being Weighed?

The majority of issues are being calculated site-wide, meaning that the whole site needs to be free of that particular issue in order to gain all of the points for it.

This table shows how the points are distributed:

Up to 30 points can be gained for resolving all issues on a per page basis with different points available depending on what level the page sites within the site structure.

• Pages at level 1 (i.e. your homepage) with multiple Level A/AA errors.
• Pages at level 2 with multiple Level A/AA errors.
• Pages at level 3+ below with multiple Level A/AA errors.

(To learn more about page levels, see article: How does Siteimprove define Page level?)

This table shows the weight of WCAG level issues per page level:

What does the Accessibility Score not include?

• Issues categorized as reviews: Potential failures to meet best practices or success criteria in the Web Content Accessibility Guidelines (WCAG), which can only be verified with a manual inspection.
• PDFs with accessibility issues do not impact the sites Accessibility score.

Website Selection

All sites included in this project were collected from publicly available databases.  

The overall accessibility score of each country is calculated by combining the overall accessibility scores of seven industries within the country:

1. Education
2. Financial Services
3. Government
4. Healthcare
5. Manufacturing
6. Retail
7. Tourism and Hospitality

For each industry, 100 websites (specific to the industry and based in that country) were randomly selected. The first 500 pages of each website were crawled.