# WIA-EDU-008 Digital Textbook Standard v1.0

## Phase 1: Data Format & Structure

**Status:** ✅ Complete
**Version:** 1.0.0
**Date:** 2025-01-15
**Philosophy:** 弘益人間 (Benefit All Humanity)

---

## 1. Overview

This specification defines the foundational data format and structure requirements for WIA-compliant digital textbooks. Phase 1 establishes EPUB3 as the mandatory format with comprehensive metadata, accessibility features, and interactive capabilities.

## 2. Scope

Phase 1 covers:
- File format requirements (EPUB3)
- Metadata schemas
- Accessibility markup
- Content structure
- Multimedia integration
- Annotation support

## 3. EPUB3 Requirements

### 3.1 Base Format

All digital textbooks MUST conform to EPUB 3.3 specification (or later) as defined by the W3C EPUB 3 Community Group.

**Mandatory Features:**
- Valid EPUB3 structure with `mimetype`, `META-INF/container.xml`, and OPF package document
- UTF-8 encoding for all text content
- HTML5 semantic markup for content documents
- CSS3 for styling
- Navigation document (nav.xhtml) using HTML5 `<nav>` element

### 3.2 File Structure

```
textbook.epub (ZIP archive with mimetype first, uncompressed)
├── mimetype                    # MUST be first file, uncompressed
├── META-INF/
│   ├── container.xml          # Points to OPF file location
│   ├── encryption.xml         # Optional: DRM info
│   └── signatures.xml         # Optional: digital signatures
├── OEBPS/  (or custom directory)
│   ├── content.opf            # Package document
│   ├── toc.ncx                # EPUB2 backward compatibility
│   ├── nav.xhtml              # EPUB3 navigation document
│   ├── chapters/
│   │   ├── chapter-01.xhtml
│   │   ├── chapter-02.xhtml
│   │   └── ...
│   ├── images/
│   │   ├── cover.jpg
│   │   └── ...
│   ├── audio/
│   ├── video/
│   ├── css/
│   │   └── styles.css
│   └── js/
│       └── interactive.js
```

## 4. Metadata Requirements

### 4.1 Dublin Core Metadata (Required)

The OPF package document MUST include the following Dublin Core metadata:

```xml
<metadata xmlns:dc="http://purl.org/dc/elements/1.1/">
  <dc:identifier id="bookid">urn:isbn:978-3-16-148410-0</dc:identifier>
  <dc:title>Introduction to Biology</dc:title>
  <dc:creator id="creator1">Smith, Jane</dc:creator>
  <dc:creator id="creator2">Doe, John</dc:creator>
  <dc:language>en-US</dc:language>
  <dc:date>2025-01-15</dc:date>
  <dc:publisher>Academic Press</dc:publisher>
  <dc:subject>Biology</dc:subject>
  <dc:subject>Life Sciences</dc:subject>
  <dc:description>A comprehensive introduction to biological sciences...</dc:description>
  <dc:rights>Copyright 2025 Academic Press. All rights reserved.</dc:rights>
</metadata>
```

### 4.2 WIA-Specific Metadata (Required)

```xml
<meta property="wia:standard">WIA-EDU-008</meta>
<meta property="wia:version">1.0</meta>
<meta property="wia:certificationDate">2025-01-15</meta>
<meta property="wia:educationLevel">Grade 9-10</meta>
<meta property="wia:contentVersion">1.0.0</meta>
<meta property="wia:wcagLevel">AA</meta>
```

### 4.3 Accessibility Metadata (Required)

Following schema.org and ONIX accessibility metadata:

```xml
<meta property="schema:accessMode">textual</meta>
<meta property="schema:accessMode">visual</meta>
<meta property="schema:accessMode">auditory</meta>
<meta property="schema:accessibilityFeature">alternativeText</meta>
<meta property="schema:accessibilityFeature">captions</meta>
<meta property="schema:accessibilityFeature">structuralNavigation</meta>
<meta property="schema:accessibilityFeature">tableOfContents</meta>
<meta property="schema:accessibilityHazard">none</meta>
<meta property="schema:accessibilityControl">fullKeyboardControl</meta>
<meta property="schema:accessibilitySummary">This publication conforms to WCAG 2.1 Level AA</meta>
```

## 5. Accessibility Requirements

### 5.1 WCAG 2.1 Level AA Compliance

All content MUST meet WCAG 2.1 Level AA criteria.

### 5.2 Images

**All images MUST have:**
- Descriptive `alt` attributes
- `role="img"` for semantic clarity
- Extended descriptions via `aria-describedby` for complex images

```html
<figure>
  <img src="images/cell-diagram.svg"
       alt="Eukaryotic cell structure showing nucleus, mitochondria, and other organelles"
       role="img"
       aria-describedby="cell-desc" />
  <figcaption id="cell-desc">
    Detailed cross-section of a eukaryotic cell. The large central nucleus
    contains chromatin and nucleolus. Surrounding organelles include...
  </figcaption>
</figure>
```

### 5.3 Mathematical Content

Mathematics MUST be encoded in MathML with alternative text:

```html
<math xmlns="http://www.w3.org/1998/Math/MathML"
      alttext="E equals m c squared">
  <mi>E</mi>
  <mo>=</mo>
  <mi>m</mi>
  <msup>
    <mi>c</mi>
    <mn>2</mn>
  </msup>
</math>
```

### 5.4 Tables

Tables MUST have:
- `<caption>` elements
- Proper `<th>` headers with `scope` attributes
- ARIA labels where appropriate

```html
<table>
  <caption>Periodic Table Elements - First 10</caption>
  <thead>
    <tr>
      <th scope="col">Atomic Number</th>
      <th scope="col">Symbol</th>
      <th scope="col">Name</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>H</td>
      <td>Hydrogen</td>
    </tr>
    <!-- ... -->
  </tbody>
</table>
```

### 5.5 Multimedia

**Video Requirements:**
- WebVTT captions for all spoken content
- Audio descriptions track for visual content
- Transcript available as alternative

```html
<video controls aria-label="Photosynthesis process">
  <source src="video/photosynthesis.mp4" type="video/mp4">
  <track kind="captions" src="captions/photosynthesis-en.vtt"
         srclang="en" label="English">
  <track kind="descriptions" src="descriptions/photosynthesis-en.vtt"
         srclang="en" label="Audio Description">
</video>

<details>
  <summary>Video Transcript</summary>
  <p>Photosynthesis is the process by which plants...</p>
</details>
```

**Audio Requirements:**
- Transcripts for all audio content
- Synchronization with visual content where applicable

## 6. Interactive Elements

### 6.1 Quizzes and Assessments

Interactive elements MUST be:
- Keyboard accessible
- Screen reader compatible
- Provide immediate feedback

```html
<section class="quiz" role="region" aria-label="Chapter 1 Self-Assessment">
  <h2>Quiz: Chapter 1</h2>

  <div class="question" role="group" aria-labelledby="q1-text">
    <p id="q1-text">What is the powerhouse of the cell?</p>
    <div role="radiogroup" aria-labelledby="q1-text">
      <label>
        <input type="radio" name="q1" value="nucleus"> Nucleus
      </label>
      <label>
        <input type="radio" name="q1" value="mitochondria"> Mitochondria
      </label>
      <label>
        <input type="radio" name="q1" value="ribosome"> Ribosome
      </label>
    </div>
  </div>

  <button type="button" onclick="checkQuiz()" aria-label="Submit quiz answers">
    Submit Answers
  </button>

  <div id="quiz-results" role="status" aria-live="polite" aria-atomic="true">
    <!-- Results appear here -->
  </div>
</section>
```

## 7. Annotation Support

### 7.1 Annotation Data Format

Textbooks MUST support the W3C Web Annotation Data Model:

```json
{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "type": "Annotation",
  "id": "urn:uuid:12345678-1234-1234-1234-123456789abc",
  "created": "2025-12-25T10:30:00Z",
  "creator": "user@example.com",
  "motivation": "highlighting",
  "target": {
    "source": "urn:isbn:978-3-16-148410-0",
    "selector": {
      "type": "FragmentSelector",
      "conformsTo": "http://www.w3.org/TR/media-frags/",
      "value": "xpointer(/html/body/section[2]/p[3])"
    }
  },
  "body": {
    "type": "TextualBody",
    "value": "Important for exam",
    "format": "text/plain",
    "language": "en"
  },
  "stylesheet": {
    "type": "CssStylesheet",
    "value": ".highlighted { background-color: #FFFF00; }"
  }
}
```

## 8. Content Versioning

### 8.1 Version Metadata

```xml
<meta property="wia:contentVersion">1.2.0</meta>
<meta property="wia:previousVersion">1.1.0</meta>
<meta property="wia:versionDate">2025-12-25</meta>
<meta property="wia:changelog">
  Updated Chapter 5 with new research findings.
  Corrected errors in Chapter 7 equations.
  Added interactive simulations to Chapter 9.
</meta>
```

## 9. Validation and Testing

### 9.1 EPUB Validation

All textbooks MUST pass EPUBCheck validation:

```bash
java -jar epubcheck.jar textbook.epub
```

### 9.2 Accessibility Testing

Accessibility MUST be validated with ACE (Accessibility Checker for EPUB):

```bash
ace textbook.epub
```

## 10. Conformance Levels

**Level 1 (Required):** EPUB3 valid, basic accessibility (WCAG A)
**Level 2 (Required):** Enhanced accessibility (WCAG AA)
**Level 3 (Recommended):** Full accessibility (WCAG AAA)

---

## Appendix A: Sample OPF Package Document

See reference implementation at: https://github.com/WIA-Official/digital-textbook/examples

## Appendix B: Validation Checklist

- [ ] EPUB3 structure valid
- [ ] EPUBCheck passes with no errors
- [ ] All required metadata present
- [ ] All images have alt text
- [ ] Math encoded in MathML
- [ ] Videos have captions
- [ ] Tables have proper headers
- [ ] Interactive elements keyboard accessible
- [ ] ACE accessibility check passes
- [ ] Navigation document present
- [ ] Content version metadata included

---

**Philosophy:** 弘益人間 · Benefit All Humanity

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License: CC BY 4.0