Fokoue, Achille
Few-shot Policy (de)composition in Conversational Question Answering
Erwin, Kyle, Axelrod, Guy, Chang, Maria, Fokoue, Achille, Crouse, Maxwell, Dan, Soham, Gao, Tian, Uceda-Sosa, Rosario, Makondo, Ndivhuwo, Khan, Naweed, Gray, Alexander
The task of policy compliance detection (PCD) is to determine if a scenario is in compliance with respect to a set of written policies. In a conversational setting, the results of PCD can indicate if clarifying questions must be asked to determine compliance status. Existing approaches usually claim to have reasoning capabilities that are latent or require a large amount of annotated data. In this work, we propose logical decomposition for policy compliance (LDPC): a neuro-symbolic framework to detect policy compliance using large language models (LLMs) in a few-shot setting. By selecting only a few exemplars alongside recently developed prompting techniques, we demonstrate that our approach soundly reasons about policy compliance conversations by extracting sub-questions to be answered, assigning truth values from contextual information, and explicitly producing a set of logic statements from the given policies. The formulation of explicit logic graphs can in turn help answer PCDrelated questions with increased transparency and explainability. We apply this approach to the popular PCD and conversational machine reading benchmark, ShARC, and show competitive performance with no task-specific finetuning. We also leverage the inherently interpretable architecture of LDPC to understand where errors occur, revealing ambiguities in the ShARC dataset and highlighting the challenges involved with reasoning for conversational question answering.
Formally Specifying the High-Level Behavior of LLM-Based Agents
Crouse, Maxwell, Abdelaziz, Ibrahim, Astudillo, Ramon, Basu, Kinjal, Dan, Soham, Kumaravel, Sadhana, Fokoue, Achille, Kapanipathi, Pavan, Roukos, Salim, Lastras, Luis
Autonomous, goal-driven agents powered by LLMs have recently emerged as promising tools for solving challenging problems without the need for task-specific finetuned models that can be expensive to procure. Currently, the design and implementation of such agents is ad hoc, as the wide variety of tasks that LLM-based agents may be applied to naturally means there can be no one-size-fits-all approach to agent design. In this work we aim to alleviate the difficulty of designing and implementing new agents by proposing a minimalistic generation framework that simplifies the process of building agents. The framework we introduce allows the user to define desired agent behaviors in a high-level, declarative specification that is then used to construct a decoding monitor which guarantees the LLM will produce an output exhibiting the desired behavior. Our declarative approach, in which the behavior is described without concern for how it should be implemented or enforced, enables rapid design, implementation, and experimentation with different LLM-based agents. We demonstrate how the proposed framework can be used to implement recent LLM-based agents (e.g., ReACT), and show how the flexibility of our approach can be leveraged to define a new agent with more complex behavior, the Plan-Act-Summarize-Solve (PASS) agent. Lastly, we demonstrate that our method outperforms other agents on multiple popular reasoning-centric question-answering benchmarks.
Learning Symbolic Rules over Abstract Meaning Representations for Textual Reinforcement Learning
Chaudhury, Subhajit, Swaminathan, Sarathkrishna, Kimura, Daiki, Sen, Prithviraj, Murugesan, Keerthiram, Uceda-Sosa, Rosario, Tatsubori, Michiaki, Fokoue, Achille, Kapanipathi, Pavan, Munawar, Asim, Gray, Alexander
Text-based reinforcement learning agents have predominantly been neural network-based models with embeddings-based representation, learning uninterpretable policies that often do not generalize well to unseen games. On the other hand, neuro-symbolic methods, specifically those that leverage an intermediate formal representation, are gaining significant attention in language understanding tasks. This is because of their advantages ranging from inherent interpretability, the lesser requirement of training data, and being generalizable in scenarios with unseen data. Therefore, in this paper, we propose a modular, NEuro-Symbolic Textual Agent (NESTA) that combines a generic semantic parser with a rule induction system to learn abstract interpretable rules as policies. Our experiments on established text-based game benchmarks show that the proposed NESTA method outperforms deep reinforcement learning-based techniques by achieving better generalization to unseen test games and learning from fewer training interactions.
MISMATCH: Fine-grained Evaluation of Machine-generated Text with Mismatch Error Types
Murugesan, Keerthiram, Swaminathan, Sarathkrishna, Dan, Soham, Chaudhury, Subhajit, Gunasekara, Chulaka, Crouse, Maxwell, Mahajan, Diwakar, Abdelaziz, Ibrahim, Fokoue, Achille, Kapanipathi, Pavan, Roukos, Salim, Gray, Alexander
With the growing interest in large language models, the need for evaluating the quality of machine text compared to reference (typically human-generated) text has become focal attention. Most recent works focus either on task-specific evaluation metrics or study the properties of machine-generated text captured by the existing metrics. In this work, we propose a new evaluation scheme to model human judgments in 7 NLP tasks, based on the fine-grained mismatches between a pair of texts. Inspired by the recent efforts in several NLP tasks for fine-grained evaluation, we introduce a set of 13 mismatch error types such as spatial/geographic errors, entity errors, etc, to guide the model for better prediction of human judgments. We propose a neural framework for evaluating machine texts that uses these mismatch error types as auxiliary tasks and re-purposes the existing single-number evaluation metrics as additional scalar features, in addition to textual features extracted from the machine and reference texts. Our experiments reveal key insights about the existing metrics via the mismatch errors. We show that the mismatch errors between the sentence pairs on the held-out datasets from 7 NLP tasks align well with the human evaluation.
An Ensemble Approach for Automated Theorem Proving Based on Efficient Name Invariant Graph Neural Representations
Fokoue, Achille, Abdelaziz, Ibrahim, Crouse, Maxwell, Ikbal, Shajith, Kishimoto, Akihiro, Lima, Guilherme, Makondo, Ndivhuwo, Marinescu, Radu
Using reinforcement learning for automated theorem proving has recently received much attention. Current approaches use representations of logical statements that often rely on the names used in these statements and, as a result, the models are generally not transferable from one domain to another. The size of these representations and whether to include the whole theory or part of it are other important decisions that affect the performance of these approaches as well as their runtime efficiency. In this paper, we present NIAGRA; an ensemble Name InvAriant Graph RepresentAtion. NIAGRA addresses this problem by using 1) improved Graph Neural Networks for learning name-invariant formula representations that is tailored for their unique characteristics and 2) an efficient ensemble approach for automated theorem proving. Our experimental evaluation shows state-of-the-art performance on multiple datasets from different domains with improvements up to 10% compared to the best learning-based approaches. Furthermore, transfer learning experiments show that our approach significantly outperforms other learning-based approaches by up to 28%.
Laziness Is a Virtue When It Comes to Compositionality in Neural Semantic Parsing
Crouse, Maxwell, Kapanipathi, Pavan, Chaudhury, Subhajit, Naseem, Tahira, Astudillo, Ramon, Fokoue, Achille, Klinger, Tim
Nearly all general-purpose neural semantic parsers generate logical forms in a strictly top-down autoregressive fashion. Though such systems have achieved impressive results across a variety of datasets and domains, recent works have called into question whether they are ultimately limited in their ability to compositionally generalize. In this work, we approach semantic parsing from, quite literally, the opposite direction; that is, we introduce a neural semantic parsing generation method that constructs logical forms from the bottom up, beginning from the logical form's leaves. The system we introduce is lazy in that it incrementally builds up a set of potential semantic parses, but only expands and processes the most promising candidate parses at each generation step. Such a parsimonious expansion scheme allows the system to maintain an arbitrarily large set of parse hypotheses that are never realized and thus incur minimal computational overhead. We evaluate our approach on compositional generalization; specifically, on the challenging CFQ dataset and three Text-to-SQL datasets where we show that our novel, bottom-up semantic parsing technique outperforms general-purpose semantic parsers while also being competitive with comparable neural parsers that have been designed for each task.
A Benchmark for Generalizable and Interpretable Temporal Question Answering over Knowledge Bases
Neelam, Sumit, Sharma, Udit, Karanam, Hima, Ikbal, Shajith, Kapanipathi, Pavan, Abdelaziz, Ibrahim, Mihindukulasooriya, Nandana, Lee, Young-Suk, Srivastava, Santosh, Pendus, Cezar, Dana, Saswati, Garg, Dinesh, Fokoue, Achille, Bhargav, G P Shrivatsa, Khandelwal, Dinesh, Ravishankar, Srinivas, Gurajada, Sairam, Chang, Maria, Uceda-Sosa, Rosario, Roukos, Salim, Gray, Alexander, Lima, Guilherme, Riegel, Ryan, Luus, Francois, Subramaniam, L Venkata
Knowledge Base Question Answering (KBQA) tasks that involve complex reasoning are emerging as an important research direction. However, most existing KBQA datasets focus primarily on generic multi-hop reasoning over explicit facts, largely ignoring other reasoning types such as temporal, spatial, and taxonomic reasoning. In this paper, we present a benchmark dataset for temporal reasoning, TempQA-WD, to encourage research in extending the present approaches to target a more challenging set of complex reasoning tasks. Specifically, our benchmark is a temporal question answering dataset with the following advantages: (a) it is based on Wikidata, which is the most frequently curated, openly available knowledge base, (b) it includes intermediate sparql queries to facilitate the evaluation of semantic parsing based approaches for KBQA, and (c) it generalizes to multiple knowledge bases: Freebase and Wikidata. The TempQA-WD dataset is available at https://github.com/IBM/tempqa-wd.
A Two-Stage Approach towards Generalization in Knowledge Base Question Answering
Ravishankar, Srinivas, Thai, June, Abdelaziz, Ibrahim, Mihidukulasooriya, Nandana, Naseem, Tahira, Kapanipathi, Pavan, Rossiello, Gaetano, Fokoue, Achille
Most existing approaches for Knowledge Base Question Answering (KBQA) focus on a specific underlying knowledge base either because of inherent assumptions in the approach, or because evaluating it on a different knowledge base requires non-trivial changes. However, many popular knowledge bases share similarities in their underlying schemas that can be leveraged to facilitate generalization across knowledge bases. To achieve this generalization, we introduce a KBQA framework based on a 2-stage architecture that explicitly separates semantic parsing from the knowledge base interaction, facilitating transfer learning across datasets and knowledge graphs. We show that pretraining on datasets with a different underlying knowledge base can nevertheless provide significant performance gains and reduce sample complexity. Our approach achieves comparable or state-of-the-art performance for LC-QuAD (DBpedia), WebQSP (Freebase), SimpleQuestions (Wikidata) and MetaQA (Wikimovies-KG).
SYGMA: System for Generalizable Modular Question Answering OverKnowledge Bases
Neelam, Sumit, Sharma, Udit, Karanam, Hima, Ikbal, Shajith, Kapanipathi, Pavan, Abdelaziz, Ibrahim, Mihindukulasooriya, Nandana, Lee, Young-Suk, Srivastava, Santosh, Pendus, Cezar, Dana, Saswati, Garg, Dinesh, Fokoue, Achille, Bhargav, G P Shrivatsa, Khandelwal, Dinesh, Ravishankar, Srinivas, Gurajada, Sairam, Chang, Maria, Uceda-Sosa, Rosario, Roukos, Salim, Gray, Alexander, Riegel, Guilherme LimaRyan, Luus, Francois, Subramaniam, L Venkata
Knowledge Base Question Answering (KBQA) tasks that in-volve complex reasoning are emerging as an important re-search direction. However, most KBQA systems struggle withgeneralizability, particularly on two dimensions: (a) acrossmultiple reasoning types where both datasets and systems haveprimarily focused on multi-hop reasoning, and (b) across mul-tiple knowledge bases, where KBQA approaches are specif-ically tuned to a single knowledge base. In this paper, wepresent SYGMA, a modular approach facilitating general-izability across multiple knowledge bases and multiple rea-soning types. Specifically, SYGMA contains three high levelmodules: 1) KB-agnostic question understanding module thatis common across KBs 2) Rules to support additional reason-ing types and 3) KB-specific question mapping and answeringmodule to address the KB-specific aspects of the answer ex-traction. We demonstrate effectiveness of our system by evalu-ating on datasets belonging to two distinct knowledge bases,DBpedia and Wikidata. In addition, to demonstrate extensi-bility to additional reasoning types we evaluate on multi-hopreasoning datasets and a new Temporal KBQA benchmarkdataset on Wikidata, namedTempQA-WD1, introduced in thispaper. We show that our generalizable approach has bettercompetetive performance on multiple datasets on DBpediaand Wikidata that requires both multi-hop and temporal rea-soning
Learning to Guide a Saturation-Based Theorem Prover
Abdelaziz, Ibrahim, Crouse, Maxwell, Makni, Bassem, Austil, Vernon, Cornelio, Cristina, Ikbal, Shajith, Kapanipathi, Pavan, Makondo, Ndivhuwo, Srinivas, Kavitha, Witbrock, Michael, Fokoue, Achille
Traditional automated theorem provers have relied on manually tuned heuristics to guide how they perform proof search. Recently, however, there has been a surge of interest in the design of learning mechanisms that can be integrated into theorem provers to improve their performance automatically. In this work, we introduce TRAIL, a deep learning-based approach to theorem proving that characterizes core elements of saturation-based theorem proving within a neural framework. TRAIL leverages (a) an effective graph neural network for representing logical formulas, (b) a novel neural representation of the state of a saturation-based theorem prover in terms of processed clauses and available actions, and (c) a novel representation of the inference selection process as an attention-based action policy. We show through a systematic analysis that these components allow TRAIL to significantly outperform previous reinforcement learning-based theorem provers on two standard benchmark datasets (up to 36% more theorems proved). In addition, to the best of our knowledge, TRAIL is the first reinforcement learning-based approach to exceed the performance of a state-of-the-art traditional theorem prover on a standard theorem proving benchmark (solving up to 17% more problems).