## Pie Chart Series: Error Distribution Analysis
### Overview
The image displays four pie charts arranged horizontally, each illustrating the percentage distribution of five distinct error types within different experimental conditions. The conditions are defined by two datasets (CWQ and WebQSP) and two knowledge graph types (CKG and IKG). A shared legend is positioned to the left of the charts.
### Components/Axes
* **Legend (Left Side):** A box containing five entries, each with a unique color/pattern and label.
* **Invalid Action Error:** Yellow with diagonal stripes (top-left to bottom-right).
* **Relation Selecting Error:** Light green with a white dot pattern.
* **Neighbor Selection Error:** Dark green with diagonal stripes (top-right to bottom-left).
* **Reasoning Error:** Red with diagonal stripes (top-right to bottom-left).
* **Decompose Error:** Pink with diagonal stripes (top-left to bottom-right).
* **Chart Titles (Top Center of each pie):**
1. CWQ (CKG)
2. CWQ (IKG)
3. WebQSP (CKG)
4. WebQSP (IKG)
* **Data Labels:** Percentage values are printed directly on each pie segment.
### Detailed Analysis
**Chart 1: CWQ (CKG)**
* **Relation Selecting Error (Green dots):** 38% (Largest segment, located top-right)
* **Reasoning Error (Red stripes):** 32% (Second largest, located bottom-left)
* **Decompose Error (Pink stripes):** 16% (Located top-left)
* **Neighbor Selection Error (Dark green stripes):** 12% (Located bottom-right)
* **Invalid Action Error (Yellow stripes):** 2% (Smallest segment, located top)
**Chart 2: CWQ (IKG)**
* **Reasoning Error (Red stripes):** 36% (Largest segment, located bottom-left)
* **Neighbor Selection Error (Dark green stripes):** 32% (Second largest, located bottom-right)
* **Decompose Error (Pink stripes):** 18% (Located top-left)
* **Relation Selecting Error (Green dots):** 10% (Located top-right)
* **Invalid Action Error (Yellow stripes):** 4% (Smallest segment, located top)
**Chart 3: WebQSP (CKG)**
* **Relation Selecting Error (Green dots):** 40% (Largest segment, located top-right)
* **Reasoning Error (Red stripes):** 34% (Second largest, located bottom-left)
* **Neighbor Selection Error (Dark green stripes):** 18% (Located bottom-right)
* **Decompose Error (Pink stripes):** 6% (Located top-left)
* **Invalid Action Error (Yellow stripes):** 2% (Smallest segment, located top)
**Chart 4: WebQSP (IKG)**
* **Reasoning Error (Red stripes):** 46% (Largest segment, located bottom-left)
* **Neighbor Selection Error (Dark green stripes):** 36% (Second largest, located bottom-right)
* **Relation Selecting Error (Green dots):** 12% (Located top-right)
* **Decompose Error (Pink stripes):** 4% (Located top-left)
* **Invalid Action Error (Yellow stripes):** 2% (Smallest segment, located top)
### Key Observations
1. **Dominant Error Shift:** The primary error type shifts dramatically between knowledge graph types. For **CKG** (Charts 1 & 3), "Relation Selecting Error" is the largest category (38%, 40%). For **IKG** (Charts 2 & 4), "Reasoning Error" becomes the largest (36%, 46%).
2. **Neighbor Selection Error Increase:** "Neighbor Selection Error" is consistently larger in IKG conditions (32%, 36%) compared to CKG conditions (12%, 18%).
3. **Decompose Error Decrease:** "Decompose Error" is notably higher in the CWQ dataset (16%, 18%) than in the WebQSP dataset (6%, 4%).
4. **Consistently Low Error:** "Invalid Action Error" remains a very small fraction (2-4%) across all four conditions.
5. **Dataset Comparison:** The WebQSP dataset shows more extreme distributions, with the largest single error category (46% Reasoning Error in IKG) and the smallest (2% Invalid Action Error).
### Interpretation
This data suggests a fundamental difference in the failure modes of systems using **CKG** versus **IKG** knowledge graphs. The shift from "Relation Selecting Error" being dominant in CKG to "Reasoning Error" and "Neighbor Selection Error" being dominant in IKG implies that the structure or accessibility of information in IKGs places a greater burden on the system's reasoning and graph traversal capabilities, rather than on identifying the correct semantic relation.
The consistently low "Invalid Action Error" indicates that the systems' basic action spaces are well-defined and rarely violated. The higher "Decompose Error" in CWQ might suggest that questions in this dataset are structurally more complex or require more sophisticated decomposition strategies than those in WebQSP.
From a debugging or system improvement perspective, the results are clear: to improve performance on **CKG**, focus on relation selection mechanisms. To improve performance on **IKG**, focus on enhancing the reasoning engine and the algorithms for selecting relevant neighboring nodes in the graph. The analysis provides a targeted roadmap for error reduction based on the underlying knowledge representation.
