Expert Systems
How Stable is Knowledge Base Knowledge?
Shrinivasan, Suhas, Razniewski, Simon
Knowledge Bases (KBs) provide structured representation of the real-world in the form of extensive collections of facts about real-world entities, their properties and relationships. They are ubiquitous in large-scale intelligent systems that exploit structured information such as in tasks like structured search, question answering and reasoning, and hence their data quality becomes paramount. The inevitability of change in the real-world, brings us to a central property of KBs -- they are highly dynamic in that the information they contain are constantly subject to change. In other words, KBs are unstable. In this paper, we investigate the notion of KB stability, specifically, the problem of KBs changing due to real-world change. Some entity-property-pairs do not undergo change in reality anymore (e.g., Einstein-children or Tesla-founders), while others might well change in the future (e.g., Tesla-board member or Ronaldo-occupation as of 2022). This notion of real-world grounded change is different from other changes that affect the data only, notably correction and delayed insertion, which have received attention in data cleaning, vandalism detection, and completeness estimation already. To analyze KB stability, we proceed in three steps. (1) We present heuristics to delineate changes due to world evolution from delayed completions and corrections, and use these to study the real-world evolution behaviour of diverse Wikidata domains, finding a high skew in terms of properties. (2) We evaluate heuristics to identify entities and properties likely to not change due to real-world change, and filter inherently stable entities and properties. (3) We evaluate the possibility of predicting stability post-hoc, specifically predicting change in a property of an entity, finding that this is possible with up to 83% F1 score, on a balanced binary stability prediction task.
INGREX: An Interactive Explanation Framework for Graph Neural Networks
Bui, Tien-Cuong, Le, Van-Duc, Li, Wen-Syan, Cha, Sang Kyun
Graph Neural Networks (GNNs) are widely used in many modern applications, necessitating explanations for their decisions. However, the complexity of GNNs makes it difficult to explain predictions. Even though several methods have been proposed lately, they can only provide simple and static explanations, which are difficult for users to understand in many scenarios. Therefore, we introduce INGREX, an interactive explanation framework for GNNs designed to aid users in comprehending model predictions. Our framework is implemented based on multiple explanation algorithms and advanced libraries. We demonstrate our framework in three scenarios covering common demands for GNN explanations to present its effectiveness and helpfulness.
Fault diagnosis for open-circuit faults in NPC inverter based on knowledge-driven and data-driven approaches
Kou, Lei, Liu, Chuang, Cai, Guo-wei, Zhou, Jia-ning, Yuan, Quan-de, Pang, Si-miao
In this study, the open-circuit faults diagnosis and location issue of the neutral-point-clamped (NPC) inverters are analysed. A novel fault diagnosis approach based on knowledge driven and data driven was presented for the open-circuit faults in insulated-gate bipolar transistors (IGBTs) of NPC inverter, and Concordia transform (knowledge driven) and random forests (RFs) technique (data driven) are employed to improve the robustness performance of the fault diagnosis classifier. First, the fault feature data of AC in either normal state or open-circuit faults states of NPC inverter are analysed and extracted. Second, the Concordia transform is used to process the fault samples, and it has been verified that the slopes of current trajectories are not affected by different loads in this study, which can help the proposed method to reduce overdependence on fault data. Moreover, then the transformed fault samples are adopted to train the RFs fault diagnosis classifier, and the fault diagnosis results show that the classification accuracy and robustness performance of the fault diagnosis classifier are improved. Finally, the diagnosis results of online fault diagnosis experiments show that the proposed classifier can locate the open-circuit fault of IGBTs in NPC inverter under the conditions of different loads.
Correcting Diverse Factual Errors in Abstractive Summarization via Post-Editing and Language Model Infilling
Balachandran, Vidhisha, Hajishirzi, Hannaneh, Cohen, William W., Tsvetkov, Yulia
Abstractive summarization models often generate inconsistent summaries containing factual errors or hallucinated content. Recent works focus on correcting factual errors in generated summaries via post-editing. Such correction models are trained using adversarial non-factual summaries constructed using heuristic rules for injecting errors. However, generating non-factual summaries using heuristics often does not generalize well to actual model errors. In this work, we propose to generate hard, representative synthetic examples of non-factual summaries through infilling language models. With this data, we train a more robust fact-correction model to post-edit the summaries to improve factual consistency. Through quantitative and qualitative experiments on two popular summarization datasets -- CNN/DM and XSum -- we show that our approach vastly outperforms prior methods in correcting erroneous summaries. Our model -- FactEdit -- improves factuality scores by over ~11 points on CNN/DM and over ~31 points on XSum on average across multiple summarization models, producing more factual summaries while maintaining competitive summarization quality.
Towards Human Cognition Level-based Experiment Design for Counterfactual Explanations (XAI)
Suffian, Muhammad, Khan, Muhammad Yaseen, Bogliolo, Alessandro
Explainable Artificial Intelligence (XAI) has recently gained a swell of interest, as many Artificial Intelligence (AI) practitioners and developers are compelled to rationalize how such AI-based systems work. Decades back, most XAI systems were developed as knowledge-based or expert systems. These systems assumed reasoning for the technical description of an explanation, with little regard for the user's cognitive capabilities. The emphasis of XAI research appears to have turned to a more pragmatic explanation approach for better understanding. An extensive area where cognitive science research may substantially influence XAI advancements is evaluating user knowledge and feedback, which are essential for XAI system evaluation. To this end, we propose a framework to experiment with generating and evaluating the explanations on the grounds of different cognitive levels of understanding. In this regard, we adopt Bloom's taxonomy, a widely accepted model for assessing the user's cognitive capability. We utilize the counterfactual explanations as an explanation-providing medium encompassed with user feedback to validate the levels of understanding about the explanation at each cognitive level and improvise the explanation generation methods accordingly.
Evaluation Metrics for Symbolic Knowledge Extracted from Machine Learning Black Boxes: A Discussion Paper
Sabbatini, Federico, Calegari, Roberta
As opaque decision systems are being increasingly adopted in almost any application field, issues about their lack of transparency and human readability are a concrete concern for end-users. Amongst existing proposals to associate human-interpretable knowledge with accurate predictions provided by opaque models, there are rule extraction techniques, capable of extracting symbolic knowledge out of an opaque model. However, how to assess the level of readability of the extracted knowledge quantitatively is still an open issue. Finding such a metric would be the key, for instance, to enable automatic comparison between a set of different knowledge representations, paving the way for the development of parameter autotuning algorithms for knowledge extractors. In this paper we discuss the need for such a metric as well as the criticalities of readability assessment and evaluation, taking into account the most common knowledge representations while highlighting the most puzzling issues.
Towards Language-driven Scientific AI
She believed that we can be hopeful that the answer is yes and that it may happen sooner than we might expect. As scientific questions become significantly more complex, our capabilities to do scientific breakthroughs need to be augmented. Compare for instance the challenges of formulating Kepler's laws of planetary motion or the discovery of a cure for Polio with demonstrating the existence of binary stellar-mass black hole systems (Abbott et al., 2016) or the treatment of glioblastoma, a type of brain cancer. While the former were achieved by a single scientist, the latter require large and interdisciplinary teams involving the collaboration of hundreds of scientists from different fields to work together during years to produce results.
Computing Rule-Based Explanations by Leveraging Counterfactuals
Geng, Zixuan, Schleich, Maximilian, Suciu, Dan
Sophisticated machine models are increasingly used for high-stakes decisions in everyday life. There is an urgent need to develop effective explanation techniques for such automated decisions. Rule-Based Explanations have been proposed for high-stake decisions like loan applications, because they increase the users' trust in the decision. However, rule-based explanations are very inefficient to compute, and existing systems sacrifice their quality in order to achieve reasonable performance. We propose a novel approach to compute rule-based explanations, by using a different type of explanation, Counterfactual Explanations, for which several efficient systems have already been developed. We prove a Duality Theorem, showing that rule-based and counterfactual-based explanations are dual to each other, then use this observation to develop an efficient algorithm for computing rule-based explanations, which uses the counterfactual-based explanation as an oracle. We conduct extensive experiments showing that our system computes rule-based explanations of higher quality, and with the same or better performance, than two previous systems, MinSetCover and Anchor.
History Of AI In 33 Breakthroughs: The First Expert System
In the early 1960s, computer scientist Ed Feigenbaum became interested in "creating models of the thinking processes of scientists, especially the processes of empirical induction by which hypotheses and theories were inferred from data." In April 1964, he met geneticist (and Noble-prize winner) Joshua Lederberg who told him how experienced chemists use their knowledge about how compounds tend to break up in a mass spectrometer to make guesses about a compound's structure. Recalling in 1987 the development of DENDRAL, the first expert system, Lederberg remarked: "…we were trying to invent AI, and in the process discovered an expert system. This shift of paradigm, 'that Knowledge IS Power' was explicated in our 1971 paper [On Generality and Problem Solving: A Case Study Using the DENDRAL Program], and has been the banner of the knowledge-based-system movement within AI research from that moment." Expert systems represented a new stage in the evolution of AI, shifting from its initial emphasis on general problem-solvers focused on expressing in code human reasoning, i.e., drawing inferences and arriving at logical conclusions.
XMD: An End-to-End Framework for Interactive Explanation-Based Debugging of NLP Models
Lee, Dong-Ho, Kadakia, Akshen, Joshi, Brihi, Chan, Aaron, Liu, Ziyi, Narahari, Kiran, Shibuya, Takashi, Mitani, Ryosuke, Sekiya, Toshiyuki, Pujara, Jay, Ren, Xiang
NLP models are susceptible to learning spurious biases (i.e., bugs) that work on some datasets but do not properly reflect the underlying task. Explanation-based model debugging aims to resolve spurious biases by showing human users explanations of model behavior, asking users to give feedback on the behavior, then using the feedback to update the model. While existing model debugging methods have shown promise, their prototype-level implementations provide limited practical utility. Thus, we propose XMD: the first open-source, end-to-end framework for explanation-based model debugging. Given task- or instance-level explanations, users can flexibly provide various forms of feedback via an intuitive, web-based UI. After receiving user feedback, XMD automatically updates the model in real time, by regularizing the model so that its explanations align with the user feedback. The new model can then be easily deployed into real-world applications via Hugging Face. Using XMD, we can improve the model's OOD performance on text classification tasks by up to 18%.