Addressing Mislabeling in Graph Data
A new method improves data quality in AI systems using graph data.
― 6 min read
Table of Contents
- The Importance of Data Quality
- The Problem with Mislabeling in Graph Data
- Introducing GraphCleaner
- Testing GraphCleaner
- Findings from Real-World Datasets
- Why Mislabeling is a Problem
- The Role of Neighborhood Dependence
- The Process of Detecting Mislabels
- Practical Implications
- Conclusion
- Original Source
- Reference Links
In the world of artificial intelligence (AI), the quality of data plays a crucial role in making systems effective. Many AI systems rely on data to learn and evaluate their performance. However, issues can arise when this data is not correct. For example, if labels or categories are wrong, it affects the results. This problem has been observed in various kinds of datasets, including those used for text, images, and audio. It is now clear that similar problems exist in graph data, which is a way of representing information in a connected manner, with nodes and edges. Graphs are used in many fields, such as social networks, biological networks, and more.
Recently, there has been a growing interest in understanding if there are errors in how the nodes in graphs are labeled. Mislabeling can lead to poor performance when AI systems are trained or evaluated using these datasets. This article discusses a new approach designed to tackle the issue of mislabeling in graph data.
The Importance of Data Quality
Data quality is vital for the successful use of AI systems. For an AI to learn effectively, it needs clean and accurate data. When datasets have mistakes or are unclear, the AI may learn incorrectly. This problem of incorrect labels is not just a minor issue; it can lead to major failures in how an AI system performs. Therefore, it is crucial to have methods that can detect and fix these errors in data before training AI systems.
The Problem with Mislabeling in Graph Data
Mislabeling has been studied mainly in traditional datasets like images and text. However, there has not been much focus on how this issue affects graph data. In graphs, nodes often have relationships with their neighbors, which means that the correct label of one node may depend on the labels of nearby nodes. This neighbor-dependent relationship is a key feature of graph data that is not fully exploited by existing methods designed for other types of data.
Introducing GraphCleaner
To address the issue of mislabeling in graph data, we introduce a method called GraphCleaner. The primary goal of GraphCleaner is to identify and correct mislabeling in graph datasets. It operates as a post-processing tool, meaning it works after an initial classification is done by another AI model.
GraphCleaner uses innovative techniques to achieve its goals. It has two main components:
Synthetic Mislabel Dataset Generation
The first component generates fake mislabels based on patterns seen in the data. This is done by looking at how labels are often incorrectly assigned in real-world scenarios. By understanding these patterns, GraphCleaner can create synthetic data that resembles mislabeling. This synthetic dataset helps train the mislabeling Detection methods more effectively.
Neighborhood-Aware Mislabel Detection
The second component focuses on using the relationships between nodes in a graph. By considering the labels of a node and its neighbors, GraphCleaner can better identify mislabeling. If a node's label does not match the expected labels of its close neighbors, it may be mislabeling. This method takes advantage of the unique structure of graphs.
Testing GraphCleaner
The effectiveness of GraphCleaner was evaluated using several datasets. The results show that GraphCleaner significantly outperforms other existing methods for detecting mislabels. This improvement was measured using metrics that assess how well the model predicts the correct labels.
Findings from Real-World Datasets
To further validate GraphCleaner's effectiveness, case studies were conducted on real-world graph datasets such as PubMed, Cora, CiteSeer, and OGB-arxiv. In these studies, GraphCleaner was able to identify previously unknown label errors.
An astonishing result from the case studies is that a substantial portion of the data in PubMed was found to be mislabelled. After correcting these errors, the evaluation performance of the algorithms using this data improved significantly. This shows the importance of ensuring data quality and highlights the value of tools like GraphCleaner.
Why Mislabeling is a Problem
The existence of mislabelled samples can lead to flawed models. If an AI system is trained on data with errors, it will likely produce incorrect predictions. In the case of graph data, this incorrect labeling can stem from various reasons:
Human Error: Mistakes can happen when data is being labeled by people, either by misunderstanding or simply by oversight.
Ambiguity: Some samples may have unclear or multiple classifications that lead to incorrect labels.
Automatic Labeling: When labels are assigned automatically, the system may make mistakes based on its underlying algorithms.
These issues can accumulate and significantly impact the performance of AI systems.
The Role of Neighborhood Dependence
Graphs are fundamentally different from other types of data due to the connections between nodes. The label of a node is not just its own label; it is also influenced by its neighbors. By recognizing this, GraphCleaner can leverage the neighborhood information to better detect mislabeling.
Nodes that strongly disagree with their neighbors' labels are often good candidates for being mislabelled. Thus, using neighbor information helps in more accurately identifying errors.
The Process of Detecting Mislabels
GraphCleaner's detection process involves several steps. First, synthetic mislabel data is generated to train the model. Then, it examines the Neighborhoods of each node to see how its label compares to those of nearby nodes. By analyzing this data, GraphCleaner is able to make informed decisions about which nodes are likely mislabelled.
Practical Implications
The ability to detect and correct mislabels in graph data has significant implications for various fields. For instance, in social networks, having accurate labels can improve user experience by enabling better recommendations. In biological networks, accurate labels can lead to better drug discovery.
Moreover, GraphCleaner can help organizations save time and resources by automating the detection of mislabels. Manual checking of data is labor-intensive and prone to errors, so tools like GraphCleaner can streamline this process.
Conclusion
Data quality is a critical factor in the success of AI systems. Mislabeling represents a major challenge, especially in graph data, where relationships between nodes matter significantly. GraphCleaner provides an efficient method for detecting and correcting these mislabels by taking advantage of the neighborhood relationships inherent in graph data.
Through extensive testing and case studies, we have seen that GraphCleaner can greatly improve the accuracy of graph datasets. This tool paves the way for better AI systems that rely on high-quality data, ultimately enhancing their performance and reliability.
As we move forward, the ongoing exploration of data quality and the characteristics associated with it will remain essential. Addressing these challenges will ensure that AI systems can serve their intended purposes effectively and responsibly.
Title: GraphCleaner: Detecting Mislabelled Samples in Popular Graph Learning Benchmarks
Abstract: Label errors have been found to be prevalent in popular text, vision, and audio datasets, which heavily influence the safe development and evaluation of machine learning algorithms. Despite increasing efforts towards improving the quality of generic data types, such as images and texts, the problem of mislabel detection in graph data remains underexplored. To bridge the gap, we explore mislabelling issues in popular real-world graph datasets and propose GraphCleaner, a post-hoc method to detect and correct these mislabelled nodes in graph datasets. GraphCleaner combines the novel ideas of 1) Synthetic Mislabel Dataset Generation, which seeks to generate realistic mislabels; and 2) Neighborhood-Aware Mislabel Detection, where neighborhood dependency is exploited in both labels and base classifier predictions. Empirical evaluations on 6 datasets and 6 experimental settings demonstrate that GraphCleaner outperforms the closest baseline, with an average improvement of 0.14 in F1 score, and 0.16 in MCC. On real-data case studies, GraphCleaner detects real and previously unknown mislabels in popular graph benchmarks: PubMed, Cora, CiteSeer and OGB-arxiv; we find that at least 6.91% of PubMed data is mislabelled or ambiguous, and simply removing these mislabelled data can boost evaluation performance from 86.71% to 89.11%.
Authors: Yuwen Li, Miao Xiong, Bryan Hooi
Last Update: 2023-05-30 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2306.00015
Source PDF: https://arxiv.org/pdf/2306.00015
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
Thank you to arxiv for use of its open access interoperability.
Reference Links
- https://www.ncbi.nlm.nih.gov/home/develop/api/
- https://paperswithcode.com/dataset/pubmed
- https://scikit-learn.org/stable/modules/generated/sklearn.metrics.f1_score.html
- https://scikit-learn.org/stable/modules/generated/sklearn.metrics.matthews_corrcoef.html
- https://en.wikipedia.org/wiki/Evaluation_measures_
- https://github.com/lywww/GraphCleaner/tree/master
- https://anonymous.4open.science/r/GraphCleaner