Learning Graph Quality Metrics Report

Overview

• Total Concepts: 258
• Foundational Concepts (no prerequisites, other concepts depend on them): 3
• Terminal Nodes (nothing depends on them, but have prerequisites): 124
• Orphaned Nodes (completely disconnected, no edges): 0
• Concepts with Dependencies: 255
• Average Dependencies per Concept: 1.26

Graph Structure Validation

• Valid DAG Structure: ✅ Yes
• Self-Dependencies: None detected ✅
• Cycles Detected: 0

Foundational Concepts

These concepts have no prerequisites:

• 1: Forensic Science Overview
• 2: Scientific Method in Forensics
• 3: Locard Exchange Principle

Dependency Chain Analysis

• Maximum Dependency Chain Length: 14

Longest Learning Path:

1. Forensic Science Overview (ID: 1)
2. Chain of Custody (ID: 16)
3. Evidence Identification (ID: 29)
4. Physical Evidence Types (ID: 34)
5. Trace Evidence (ID: 35)
6. Stages of Decomposition (ID: 186)
7. Blowfly Lifecycle (ID: 192)
8. Insect Egg Stage (ID: 194)
9. Larval Instar Stages (ID: 195)
10. Blowfly Pupa Stage (ID: 196)
11. Accumulated Degree Hours (ID: 197)
12. Accumulated Degree Days (ID: 198)
13. Minimum Post-Mortem Interval (ID: 199)
14. Environmental Variables in PMI (ID: 201)

Terminal Nodes Analysis

Terminal nodes are concepts that nothing else depends on but have prerequisites. They represent natural endpoints of learning paths — culminating or specialized concepts.

• Total Terminal Nodes: 124 (48.1% of all concepts)
• Healthy Range: 5-40% of total concepts

Concepts at the end of learning paths:

• 7: Expert Witness Ethics
• 8: Evidence Admissibility
• 10: Fifth Amendment Rights
• 12: Warrant Requirements
• 14: Criminal vs Civil Standards
• 15: Criminal Justice Structure
• 18: Crime Scene Perimeter Security
• 19: Primary vs Secondary Scenes
• 21: Crime Scene Photography
• 24: Triangulation Measurement
• 26: Grid Search Pattern
• 27: Spiral Search Pattern
• 28: Zone Search Pattern
• 32: Druggist Fold Technique
• 33: Biohazard Evidence Containers
• 38: Dermal Papillae
• 42: Ulnar vs Radial Loops
• 43: Whorl Subtypes
• 44: Tented Arch Pattern
• 48: Patent Fingerprints

...and 104 more

Orphaned Nodes Analysis

Orphaned nodes are completely disconnected concepts with no inbound AND no outbound edges. These indicate a quality problem — every concept should connect to the graph.

• Total Orphaned Nodes: 0

✅ No orphaned nodes detected. All concepts are connected to the graph.

Connected Components

• Number of Connected Components: 1

✅ All concepts are connected in a single graph.

Indegree Analysis

Top 10 concepts that are prerequisites for the most other concepts:

Rank	Concept ID	Concept Label	Indegree
1	35	Trace Evidence	26
2	1	Forensic Science Overview	11
3	37	Friction Ridge Skin	8
4	86	Blood Composition	8
5	136	Pharmacokinetics (ADME)	8
6	238	Digital Forensics Overview	8
7	155	Fire Tetrahedron	7
8	186	Stages of Decomposition	7
9	203	Internal Ballistics	7
10	223	Handwriting Analysis	6

Outdegree Distribution

Dependencies	Number of Concepts
0	3
1	197
2	49
3	9

Recommendations

• ℹ️ High terminal node percentage (48.1%): Consider if some terminal concepts should be prerequisites for advanced concepts
• ✅ DAG structure verified: Graph supports valid learning progressions
• ℹ️ Consider adding cross-dependencies: More connections could create richer learning pathways

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Report generated by learning-graph-reports/analyze_graph.py