Gökhan Tür

Also published as: G. Tur, Gokhan Tur, Gokhan Tür


2021

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Generative Conversational Networks
Alexandros Papangelis | Karthik Gopalakrishnan | Aishwarya Padmakumar | Seokhwan Kim | Gokhan Tur | Dilek Hakkani-Tur
Proceedings of the 22nd Annual Meeting of the Special Interest Group on Discourse and Dialogue

Inspired by recent work in meta-learning and generative teaching networks, we propose a framework called Generative Conversational Networks, in which conversational agents learn to generate their own labelled training data (given some seed data) and then train themselves from that data to perform a given task. We use reinforcement learning to optimize the data generation process where the reward signal is the agent’s performance on the task. The task can be any language-related task, from intent detection to full task-oriented conversations. In this work, we show that our approach is able to generalise from seed data and performs well in limited data and limited computation settings, with significant gains for intent detection and slot tagging across multiple datasets: ATIS, TOD, SNIPS, and Restaurants8k. We show an average improvement of 35% in intent detection and 21% in slot tagging over a baseline model trained from the seed data. We also conduct an analysis of the novelty of the generated data and provide generated examples for intent detection, slot tagging, and non-goal oriented conversations.

2020

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Controllable Text Generation with Focused Variation
Lei Shu | Alexandros Papangelis | Yi-Chia Wang | Gokhan Tur | Hu Xu | Zhaleh Feizollahi | Bing Liu | Piero Molino
Findings of the Association for Computational Linguistics: EMNLP 2020

This work introduces Focused-Variation Network (FVN), a novel model to control language generation. The main problems in previous controlled language generation models range from the difficulty of generating text according to the given attributes, to the lack of diversity of the generated texts. FVN addresses these issues by learning disjoint discrete latent spaces for each attribute inside codebooks, which allows for both controllability and diversity, while at the same time generating fluent text. We evaluate FVN on two text generation datasets with annotated content and style, and show state-of-the-art performance as assessed by automatic and human evaluations.

2019

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Collaborative Multi-Agent Dialogue Model Training Via Reinforcement Learning
Alexandros Papangelis | Yi-Chia Wang | Piero Molino | Gokhan Tur
Proceedings of the 20th Annual SIGdial Meeting on Discourse and Dialogue

Some of the major challenges in training conversational agents include the lack of large-scale data of real-world complexity, defining appropriate evaluation measures, and managing meaningful conversations across many topics over long periods of time. Moreover, most works tend to assume that the conversational agent’s environment is stationary, a somewhat strong assumption. To remove this assumption and overcome the lack of data, we take a step away from the traditional training pipeline and model the conversation as a stochastic collaborative game. Each agent (player) has a role (“assistant”, “tourist”, “eater”, etc.) and their own objectives, and can only interact via language they generate. Each agent, therefore, needs to learn to operate optimally in an environment with multiple sources of uncertainty (its own LU and LG, the other agent’s LU, Policy, and LG). In this work, we present the first complete attempt at concurrently training conversational agents that communicate only via self-generated language and show that they outperform supervised and deep learning baselines.

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Flexibly-Structured Model for Task-Oriented Dialogues
Lei Shu | Piero Molino | Mahdi Namazifar | Hu Xu | Bing Liu | Huaixiu Zheng | Gokhan Tur
Proceedings of the 20th Annual SIGdial Meeting on Discourse and Dialogue

This paper proposes a novel end-to-end architecture for task-oriented dialogue systems. It is based on a simple and practical yet very effective sequence-to-sequence approach, where language understanding and state tracking tasks are modeled jointly with a structured copy-augmented sequential decoder and a multi-label decoder for each slot. The policy engine and language generation tasks are modeled jointly following that. The copy-augmented sequential decoder deals with new or unknown values in the conversation, while the multi-label decoder combined with the sequential decoder ensures the explicit assignment of values to slots. On the generation part, slot binary classifiers are used to improve performance. This architecture is scalable to real-world scenarios and is shown through an empirical evaluation to achieve state-of-the-art performance on both the Cambridge Restaurant dataset and the Stanford in-car assistant dataset.

2018

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Dialogue Learning with Human Teaching and Feedback in End-to-End Trainable Task-Oriented Dialogue Systems
Bing Liu | Gokhan Tür | Dilek Hakkani-Tür | Pararth Shah | Larry Heck
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)

In this work, we present a hybrid learning method for training task-oriented dialogue systems through online user interactions. Popular methods for learning task-oriented dialogues include applying reinforcement learning with user feedback on supervised pre-training models. Efficiency of such learning method may suffer from the mismatch of dialogue state distribution between offline training and online interactive learning stages. To address this challenge, we propose a hybrid imitation and reinforcement learning method, with which a dialogue agent can effectively learn from its interaction with users by learning from human teaching and feedback. We design a neural network based task-oriented dialogue agent that can be optimized end-to-end with the proposed learning method. Experimental results show that our end-to-end dialogue agent can learn effectively from the mistake it makes via imitation learning from user teaching. Applying reinforcement learning with user feedback after the imitation learning stage further improves the agent’s capability in successfully completing a task.

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Bootstrapping a Neural Conversational Agent with Dialogue Self-Play, Crowdsourcing and On-Line Reinforcement Learning
Pararth Shah | Dilek Hakkani-Tür | Bing Liu | Gokhan Tür
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 3 (Industry Papers)

End-to-end neural models show great promise towards building conversational agents that are trained from data and on-line experience using supervised and reinforcement learning. However, these models require a large corpus of dialogues to learn effectively. For goal-oriented dialogues, such datasets are expensive to collect and annotate, since each task involves a separate schema and database of entities. Further, the Wizard-of-Oz approach commonly used for dialogue collection does not provide sufficient coverage of salient dialogue flows, which is critical for guaranteeing an acceptable task completion rate in consumer-facing conversational agents. In this paper, we study a recently proposed approach for building an agent for arbitrary tasks by combining dialogue self-play and crowd-sourcing to generate fully-annotated dialogues with diverse and natural utterances. We discuss the advantages of this approach for industry applications of conversational agents, wherein an agent can be rapidly bootstrapped to deploy in front of users and further optimized via interactive learning from actual users of the system.

2017

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Sequential Dialogue Context Modeling for Spoken Language Understanding
Ankur Bapna | Gokhan Tür | Dilek Hakkani-Tür | Larry Heck
Proceedings of the 18th Annual SIGdial Meeting on Discourse and Dialogue

Spoken Language Understanding (SLU) is a key component of goal oriented dialogue systems that would parse user utterances into semantic frame representations. Traditionally SLU does not utilize the dialogue history beyond the previous system turn and contextual ambiguities are resolved by the downstream components. In this paper, we explore novel approaches for modeling dialogue context in a recurrent neural network (RNN) based language understanding system. We propose the Sequential Dialogue Encoder Network, that allows encoding context from the dialogue history in chronological order. We compare the performance of our proposed architecture with two context models, one that uses just the previous turn context and another that encodes dialogue context in a memory network, but loses the order of utterances in the dialogue history. Experiments with a multi-domain dialogue dataset demonstrate that the proposed architecture results in reduced semantic frame error rates.

2013

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Semi-Supervised Semantic Tagging of Conversational Understanding using Markov Topic Regression
Asli Celikyilmaz | Dilek Hakkani-Tur | Gokhan Tur | Ruhi Sarikaya
Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

2012

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Mining Search Query Logs for Spoken Language Understanding
Dilek Hakkani-Tür | Gokhan Tür | Asli Celikyilmaz
NAACL-HLT Workshop on Future directions and needs in the Spoken Dialog Community: Tools and Data (SDCTD 2012)

2010

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NAACL HLT 2010 Tutorial Abstracts
Jason Baldwin | Peter Clark | Gokhan Tur
NAACL HLT 2010 Tutorial Abstracts

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LDA Based Similarity Modeling for Question Answering
Asli Celikyilmaz | Dilek Hakkani-Tur | Gokhan Tur
Proceedings of the NAACL HLT 2010 Workshop on Semantic Search

2009

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Who, What, When, Where, Why? Comparing Multiple Approaches to the Cross-Lingual 5W Task
Kristen Parton | Kathleen R. McKeown | Bob Coyne | Mona T. Diab | Ralph Grishman | Dilek Hakkani-Tür | Mary Harper | Heng Ji | Wei Yun Ma | Adam Meyers | Sara Stolbach | Ang Sun | Gokhan Tur | Wei Xu | Sibel Yaman
Proceedings of the Joint Conference of the 47th Annual Meeting of the ACL and the 4th International Joint Conference on Natural Language Processing of the AFNLP

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Anchored Speech Recognition for Question Answering
Sibel Yaman | Gokhan Tur | Dimitra Vergyri | Dilek Hakkani-Tur | Mary Harper | Wen Wang
Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics, Companion Volume: Short Papers

2007

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Proceedings of the Workshop on Bridging the Gap: Academic and Industrial Research in Dialog Technologies
Fuliang Weng | Ye-Yi Wang | Gokhan Tur
Proceedings of the Workshop on Bridging the Gap: Academic and Industrial Research in Dialog Technologies

2005

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Using Semantic and Syntactic Graphs for Call Classification
Dilek Hakkani-Tür | Gokhan Tur | Ananlada Chotimongkol
Proceedings of the ACL Workshop on Feature Engineering for Machine Learning in Natural Language Processing

2004

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Bootstrapping Spoken Dialog Systems with Data Reuse
Guiseppe Di Fabbrizio | Gokhan Tur | Dilek Hakkani-Tür
Proceedings of the 5th SIGdial Workshop on Discourse and Dialogue at HLT-NAACL 2004

2001

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Integrating Prosodic and Lexical Cues for Automatic Topic Segmentation
G. Tur | D. Hakkani-Tur | A. Stolcke | E. Shriberg
Computational Linguistics, Volume 27, Number 1, March 2001

2000

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Statistical Morphological Disambiguation for Agglutinative Languages
Dilek Z. Hakkani-Tür | Kemal Oflazer | Gökhan Tür
COLING 2000 Volume 1: The 18th International Conference on Computational Linguistics

1998

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Tagging English by Path Voting Constraints
Gokhan Tur | Kemal Oflazer
COLING 1998 Volume 2: The 17th International Conference on Computational Linguistics

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Implementing Voting Constraints with Finite State Transducers
Kemal Oflazer | Gokhan Tur
Finite State Methods in Natural Language Processing

1997

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Morphological Disambiguation by Voting Constraints
Kemal Oflazer | Gokhan Tur
35th Annual Meeting of the Association for Computational Linguistics and 8th Conference of the European Chapter of the Association for Computational Linguistics

1996

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Combining Hand-crafted Rules and Unsupervised Learning in Constraint-based Morphological Disambiguation
Kemal Oflazer | Gokhan Tur
Conference on Empirical Methods in Natural Language Processing