Learning Graph Quality Metrics Report¶

Overview¶

Total Concepts: 500
Foundational Concepts (no prerequisites, other concepts depend on them): 21
Terminal Nodes (nothing depends on them, but have prerequisites): 213
Orphaned Nodes (completely disconnected, no edges): 0
Concepts with Dependencies: 479
Average Dependencies per Concept: 1.80

Graph Structure Validation¶

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

Foundational Concepts¶

These concepts have no prerequisites:

1: Hydroponics Definition
9: Plant Growth Fundamentals
10: Cell Biology Basics
78: pH Scale Definition
81: Electrical Conductivity (EC)
83: Parts Per Million (ppm)
220: Relative Humidity Definition
234: Data Logger Basics
246: MicroPython vs CPython
247: Raspberry Pi Pico Overview
249: ESP32 Microcontroller Overview
277: I2C Protocol Basics
279: SPI Protocol Basics
282: Analog-to-Digital Converter
285: PWM: Pulse Width Modulation
297: MQTT Protocol Basics
352: Python Environment Setup
369: Linear Regression
416: Solar Energy Basics
428: Battery Storage Basics
471: Capital Budgeting Basics

Dependency Chain Analysis¶

Maximum Dependency Chain Length: 19

Longest Learning Path:¶

MicroPython vs CPython (ID: 246)
MicroPython Installation (ID: 250)
Thonny IDE Setup (ID: 251)
REPL (Read-Eval-Print Loop) (ID: 252)
Variables and Data Types (ID: 253)
Boolean Logic (ID: 256)
If-Else Statements (ID: 261)
For Loops (ID: 262)
Functions and def Keyword (ID: 265)
Exception Handling Try/Except (ID: 271)
File I/O in MicroPython (ID: 272)
Writing and Appending Files (ID: 274)
CSV File Writing in MicroPython (ID: 275)
CSV File Format and Structure (ID: 348)
Reading CSV With pandas (ID: 356)
Plotly Express Line Chart (ID: 378)
Plotly Interactive Dashboard (ID: 379)
Dash Framework (Plotly Dash) (ID: 380)
Real-Time Dashboard Updates (ID: 381)

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: 213 (42.6% of all concepts)
Healthy Range: 5-40% of total concepts

Concepts at the end of learning paths:

3: William Frederick Gericke
5: Soil vs Soilless Comparison
12: Cellular Respiration Overview
18: Harvest and Post-Harvest
25: Hydroponics vs Aquaponics
34: Xylem Transport
35: Phloem Transport
36: Stomata Function
37: Leaf Structure
40: Calvin Cycle
41: Chlorophyll and Pigments
43: Rhizosphere Chemistry
44: Cation Exchange at Root Surface
46: Root Adaptation to Hydroponics
50: Ethylene as Stress Hormone
54: Blossom End Rot
55: Interveinal Chlorosis
56: Purple Stem Syndrome
57: Necrosis Patterns
60: Fresh Weight vs Dry Weight

...and 193 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	4	Soilless Growing Systems	25
2	265	Functions and def Keyword	22
3	446	Vertical Farming Definition	22
4	101	Passive vs Active Systems	15
5	84	Nutrient Solution Concentration	14
6	250	MicroPython Installation	13
7	26	Root Anatomy	11
8	173	Crop Selection by System Type	11
9	234	Data Logger Basics	10
10	391	Food Safety in Controlled Envs	10

Outdegree Distribution¶

Dependencies	Number of Concepts
0	21
1	182
2	224
3	63
4	8
5	2

Recommendations¶

ℹ️ High terminal node percentage (42.6%): Consider if some terminal concepts should be prerequisites for advanced concepts
✅ DAG structure verified: Graph supports valid learning progressions
ℹ️ Long dependency chains (19): Ensure students can follow extended learning paths

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