Accessibility Foundations: Core Concepts for Web Accessibility and Performance

Build the mental model

Accessibility Foundations focuses on this learner need: Make interfaces perceivable, operable, understandable, and robust by using semantic HTML, keyboard support, labels, focus management, contrast, and repeatable accessibility checks. Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces.

Track the changing state and identify the evidence that makes that state observable.

Identify the parts and boundaries

In Accessibility Foundations, semantic structure and accessible names. Keyboard/focus behavior. Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces.

1. 1

   Semantic structure and accessible names.

2. 2

   Keyboard/focus behavior.

3. 3

   Contrast and non-color cues.

4. 4

   Automated plus manual accessibility testing.

Trace one concrete case

Choose one realistic input for Accessibility Foundations and trace it using this path lens: Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces. Predict the result before running the example, then compare prediction with evidence.

If the prediction fails, identify the assumption before changing the implementation.

ACCESSIBILITY FOUNDATIONS
=========================
1. Semantic structure and accessible names.
2. Keyboard/focus behavior.
3. Contrast and non-color cues.
4. Automated plus manual accessibility testing.
Evidence: the module-specific command, output, test, rendered state, query result, log, or measurement that proves the exercise worked

Read the concept map, predict one concrete result, then compare that prediction with the module example or native tool.

A module-specific concept trace connecting core decisions to observable evidence.

practice/\n├── README.md\n├── accessibility-foundations-concept-map.txt\n└── evidence/\n    └── expected-result.txt

Compare a nearby alternative

For Accessibility Foundations, compare the shown mechanism with a nearby alternative. Use this technical point—Contrast and non-color cues.—inside this path context: Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces.

State the tradeoff in your own words.

Explain it back with evidence

Summarize Accessibility Foundations without reading the example. Explain the input or state, operation or decision, and result through this implementation lens: Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces.

For Accessibility Foundations, use this evidence standard: the module-specific command, output, test, rendered state, query result, log, or measurement that proves the exercise worked. Interpret the evidence through this path context: Use semantic structure, keyboard behavior, accessible names, contrast, loading metrics, runtime measurements, and browser tooling to verify inclusive fast interfaces.

Common mistakes to avoid

• Clickable div has no keyboard behavior.
• Form control lacks accessible label.
• Focus indicator removed.
• Color alone communicates status.