WCAG-EM — Website Accessibility Conformance Evaluation Methodology

In this tutorial, you will learn about WCAG. We cover key concepts, practical examples, and best practices to help you master this topic.

WCAG-EM is the W3C's structured methodology for evaluating website conformance to WCAG, providing a five-step Process from scope definition to reporting that ensures thorough, reproducible, and documented Accessibility evaluations.

What You'll Learn

You will learn the WCAG-EM evaluation methodology, its five steps, how to apply it to your website, and how to produce a WCAG-EM report.

Why It Matters

WCAG-EM is the W3C-recommended method for evaluating conformance. Using it ensures your evaluation is thorough, reproducible, and credible. Courts and procurement officers recognize WCAG-EM.

Real-World Use

DodaTech uses WCAG-EM for annual accessibility audits. Each product undergoes a full WCAG-EM evaluation with documented results that support the conformance claim.

flowchart LR
  A[Step 1: Scope] --> B[Step 2: Sample]
  B --> C[Step 3: Evaluate]
  C --> D[Step 4: Report]
  D --> E[Step 5: Maintain]
  A:::current
  classDef current fill:#f90,color:#fff,stroke:#333,stroke-width:2px

The Five Steps

Step 1: Define Scope

Define which web pages, functionality, and content are included in the evaluation. Document the WCAG version and conformance level being evaluated.

Step 2: Select Sample

Choose a representative sample of pages. Include different page types, templates, and functionality. WCAG-EM provides guidance on sample size based on site complexity.

Step 3: Evaluate Sample

Test each page in the sample against all applicable success criteria. Use automated tools, manual testing, and assistive technology testing. Document results for each criterion.

Step 4: Report Results

Create an evaluation report that includes scope, methodology, sample, results, and conformance conclusion.

Step 5: Maintain (Optional)

Update the evaluation as the site changes. Regular evaluations ensure ongoing conformance.

function wcagEMPlan(siteSize, pageTypes) {
  const sampleSizes = {
    small: 5,
    medium: 10,
    large: 20,
    enterprise: 30
  };

  return {
    siteSize,
    pageTypes: pageTypes.length,
    sampleSize: sampleSizes[siteSize] || 10,
    pagesPerType: Math.ceil(sampleSizes[siteSize] / pageTypes.length),
    effortHours: sampleSizes[siteSize] * 4, // 4 hours per page
    recommendedTools: ['axe-core', 'WAVE', 'NVDA', 'manual keyboard testing']
  };
}

console.log(wcagEMPlan('medium', ['Home', 'Content', 'Form', 'Search', 'Dashboard']));

Expected output:

{
  siteSize: 'medium',
  pageTypes: 5,
  sampleSize: 10,
  pagesPerType: 2,
  effortHours: 40,
  recommendedTools: ['axe-core', 'WAVE', 'NVDA', 'manual keyboard testing']
}

WCAG-EM Report Template

A WCAG-EM report includes: evaluation scope, WCAG version and level, evaluation date, evaluation team, sample page list, evaluation tool list, results by success criterion, conclusion, and recommendations.

Benefits of WCAG-EM

Reproducible methodology means your evaluation can be verified by others. It supports conformance claims with documented evidence. It identifies specific success criteria that need remediation.

Common Mistakes

1. Not Using a Structured Methodology

Ad hoc evaluations miss criteria and lack reproducibility. Following WCAG-EM ensures thoroughness.

2. Sample Too Small

Evaluating only the homepage misses issues on other page types. Include different templates and functionality.

3. No Documentation of Methodology

Without documentation, you cannot prove what was tested or how. Document every step.

4. Relying Only on Automated Tools

WCAG-EM requires manual testing. Automated tools alone do not satisfy the methodology.

5. Not Updating the Evaluation

An evaluation from 12 months ago may not reflect the current site. Regular updates are essential.

6. Missing Contextual Criteria

Some criteria cannot be evaluated on isolated pages. Multi-page processes need combined evaluation.

7. Not Including User Testing

WCAG-EM recommends but does not require user testing. Including it strengthens the evaluation.

Practice Questions

1. What does WCAG-EM stand for?

Website Accessibility Conformance Evaluation Methodology, developed by W3C WAI.

2. What are the five steps of WCAG-EM?

Define scope, select sample, evaluate sample, report results, maintain.

3. Why is WCAG-EM preferred over ad hoc evaluation?

It provides a reproducible, documented methodology that supports conformance claims and is recognized by courts.

4. How many pages should be included in a sample for a medium-sized site?

WCAG-EM recommends approximately 10 pages for a medium site, including different page types.

5. Challenge: Apply WCAG-EM Step 1 and Step 2 to your website. Define the scope and select a representative sample of pages.

FAQ

Mini Project

Complete a WCAG-EM evaluation for a single page of your website. Document the scope, methodology, sample, evaluation results (5+ criteria), and a brief report.

What's Next

Learn about WCAG for Designers with practical guidance for creating accessible designs. Then explore WCAG for Developers for implementation techniques.