[metrics] Modify index.md & add examples.md

docs/examples.md

+# Examples
+
+This collection contains representative example queries that serve as entry points for using the NFDI4Earth KnowledgeGraph.
+
+## About this Collection
+
+The SPARQL queries presented here demonstrate fundamental query patterns and typical use cases. They are intentionally kept simple and serve as:
+
+- Examples for commonly needed query types
+- Templates for your own, more complex queries
+- Learning material for SPARQL beginners
+
+## Educational Resources Example
+
+This example demonstrates how to retrieve comprehensive information about educational resources from the NFDI4Earth Knowledge Hub.
+
+### Query Purpose
+
+The query finds all learning resources and their associated metadata, including:
+
+- Publishers and their names
+- Subject areas with labels
+- Licensing information
+- Related topics and their titles
+
+### SPARQL Features Demonstrated
+
+- Use of `CONSTRUCT` for graph pattern matching
+- Multiple `OPTIONAL` patterns for flexible data retrieval
+- Property path navigation
+- Handling of multiple vocabularies (schema.org, FOAF, DCT)
+
+### Query
+
+```sparql
+{{ include_if_exists("examples/Educational resources.rq") }}
+```
+
+### Understanding the Results
+
+The query returns a graph structure where:
+
+- Each learning resource is connected to its direct properties
+- Additional metadata about publishers, subjects, and licenses is included
+- Labels and titles are retrieved for better human readability
+
+
+## Repository Metadata Standards Example
+
+This example shows how to query metadata standards and API types supported by repositories in the NFDI4Earth Knowledge Hub.
+
+### Query Purpose
+
+The query retrieves information about:
+- Repository names
+- Supported metadata standards
+- Available API types and interfaces
+
+### SPARQL Features Demonstrated
+
+- Basic `SELECT` query structure
+- Multiple triple patterns
+- Property traversal
+- Use of domain-specific vocabularies (n4e)
+
+### Query
+
+```sparql
+{{ include_if_exists("examples/Metadata.rq") }}
+```
+
+### Understanding the Results
+
+The query returns:
+
+- Repository names for clear identification
+- Names of supported metadata standards
+- Types of APIs available for each repository
+
+This information is particularly useful for:
+
+- Understanding repository capabilities
+- Planning data integration
+- Evaluating technical compatibility
+
+## NFDI4Earth Services Example
+
+This example demonstrates how to query services that are provided by organizations within the NFDI4Earth consortium.
+
+### Query Purpose
+
+The query identifies:
+- Services (Repositories and Aggregators)
+- Their names and types
+- Publishing organizations within NFDI4Earth
+- Including services from sub-organizations
+
+### SPARQL Features Demonstrated
+
+- Complex `SELECT` query with `GROUP_CONCAT`
+- `UNION` patterns for alternative paths
+- Organization hierarchy traversal
+- Filter conditions with `NOT EXISTS`
+- Value constraints using `VALUES`
+
+### Query
+
+```sparql
+{{ include_if_exists("examples/Services in the NFDI4Earth.rq") }}
+```
+
+### Understanding the Results
+
+The query returns:
+
+- Service names and their types (Repository or Aggregator)
+- Concatenated list of publishing organizations
+- Services from both direct NFDI4Earth members and their sub-organizations
+
+This query is useful for:
+
+- Getting an overview of NFDI4Earth service landscape
+- Understanding organizational relationships
+- Service discovery and analysis
\ No newline at end of file

docs/index.md

@@ -2,20 +2,60 @@
 
 Welcome to the NFDI4Earth KnowledgeGraph Query Collection. This documentation provides insights into the NFDI4Earth KnowledgeHub Graph through SPARQL queries and their analysis.
 
+## About the Project
+
+The NFDI4Earth KnowledgeGraph represents a comprehensive network of earth science research data, connecting various domains, datasets, and research artifacts. Based on the NFDI4Earth metadata schema, it enables:
+
+- **Linked Research Data**: Integration of various data sources and research artifacts
+- **Semantic Search**: Intelligent discovery of relevant resources
+- **Community Integration**: Connecting researchers and their work
+
 ## Purpose
 
-The NFDI4Earth KnowledgeGraph represents a comprehensive network of earth science research data, connecting various domains, datasets, and research artifacts. Through SPARQL queries, we explore:
+Through SPARQL queries, we explore:
 
 - **Data Discovery**: Finding relevant research data across earth science domains
 - **Domain Coverage**: Understanding the breadth and depth of represented research areas
 - **Graph Structure**: Analyzing the knowledge graph's characteristics and connectivity
 
-## Exploration Areas
+## Query Collection
+
+Our queries are organized into three main categories.
+
+[**1. Basic Examples**](/examples)
+
+   - Common query patterns
+   - Graph exploration basics
+   - Getting started guides
+
+[**2. Domain Questions**](/questions)
+
+   - Domain-specific research questions
+   - Real-world use cases
+   - Complex query patterns
+
+[**3. Graph Metrics**](/metrics)
+
+   - Structural metrics
+   - Quality analysis
+   - Network characteristics
+
+## Getting Started
+
+Each query is documented with:
+- Detailed description of the use case
+- SPARQL code with explanations
+- Example results and visualizations
+- Interpretation guidelines
+- Performance considerations
+
+## Contributing
 
-We collect queries for three main purposes:
+We invite the community to contribute their own queries!
 
-1. **Basic Examples** to demonstrate common query patterns and graph exploration
-2. **Domain Questions** addressing specific research data discovery needs
-3. **Graph Metrics** providing insights into the knowledge graph's structure
+## Resources
 
-Each query is documented with its purpose, expected results, and practical implications for understanding and utilizing the NFDI4Earth KnowledgeHub.
+- [NFDI4Earth OneStop4All](https://onestop4all.nfdi4earth.de)
+- [KnowledgeHub Documentation](https://knowledgehub.nfdi4earth.de)
+- [SPARQL Endpoint](https://sparql.knowledgehub.nfdi4earth.de)
+- [GitHub Repository](https://git.rwth-aachen.de/nfdi4earth/knowledgehub/kh_questions)