generally divided into four modules. NLU Natural Language Understanding DST Dialogue State Tracking NLG Natural Language Generation DP Dialogue Policy learning For how many people? Can you help me book a restaurant near Hoegi Station? Dialogue state tracking
Dialogue State Tracking NLG Natural Language Generation DP Dialogue Policy learning people_num=5 Restaurant_Book (Area = Hoegi) Restaurant_Book (Area = Hoegi, people_num = 5) DST is a dialogue-level task that maps partial dialogues into dialogue states. • Input: a dialogue / a turn • Output: dialogue state (e.g. slot-value pairs) Can you help me book a restaurant near Hoegi Station? For five people, thanks! Dialogue state tracking
that maps partial dialogues into dialogue states. • Input: a dialogue / a turn with its previous state • Output: dialogue state (e.g. slot-value pairs) Dialogue state tracking USER : Can you help me book a restaurant near Hoegi Station? SYSTEM : For how many people? USER : For five people, thanks! Input Dialogue Restaurant_Book (Area = Hoegi station) Restaurant_Book (Area = Hoegi station, people_num=5) Output Dialogue State
Dialogue State Tracking NLG Natural Language Generation DP Dialogue Policy learning For how many people? Can you help me book a restaurant near Hoegi Station? Dialogue state tracking
task descriptions • Modify the input data to include a description of slot or examples of slot value[1] • Slot descriptions improve zero-shot transferability[2] • Generally, the inference is high cost because it get slot value one by one in turn. [1] Robust Zero-Shot Cross-Domain Slot Filling with Example Values, ACL 2019 [2] Leveraging Slot Descriptions for Zero-Shot Cross-Domain Dialogue State Tracking, NAACL 2021 Dialogue state tracking
• Powerful language models like GPT[1] demonstrated impressive few-shot learning ability even without fine-tuning • Madotto et al.[2] applied GPT-2 by priming the model with examples for language understanding, state tracking, dialogue policy and language generation tasks respectively • Describe task with questions • Dialogue state tracking as a question answering (QA) or machine reading (MR) problem[3],[4] [1] Language models are unsupervised multitask learners, 2018 [2] Language models as few-shot learner for task-oriented dialogue systems, 2020 [3] Zero-shot generalization in dialog state tracking through generative question answering, EACL 2021 [4] From machine reading comprehension to dialogue state tracking: Bridging the gap, ACL 2020 Dialogue state tracking
• Seq2seq can easily handle different formats of language instructions • Seq2seq has been shown to be an effective approach for DST[1] • Use T5[2] from google [1] Effective sequence-tosequence dialogue state tracking, ACL 2021 [2] Exploring the limits of transfer learning with a unified text-to-text transformer, JMLR 2020 D3ST
the song is to be played 0a) bedroom speaker 0b) tv 0c) kitchen speaker 1=name of the artist the song is performed by 2=name of the song 3=album the song belongs to 4=genre of the song i0=search for a song based on the name and optionally other attributes i1=play a song by its name and optionally artist [user] i want to find a movie. [system] what is your location. [user] santa rosa. i want to see it at 3rd street cinema. [system] i found 3 movies. does hellboy, how to train your dragon: the hidden world or the upside interest you? [user] how to train your dragon: the hidden world is perfect. can you find me some songs from the album summer anthems. [states] 1:1a 2:summer anthems 4:no other love [intents] i0
are categorical(ex : hotel provides free wi-fi or not -> yes or no) • For categorical slot, provide categorical value. • i: 𝑑𝑖 𝑠𝑙𝑜𝑡𝑖𝑎) 𝑣𝑎 … 𝑖𝑘)𝑣𝑘 • Property • Other description dialogue system hardly rely on description to perform task • But D3ST use index-picking mechanism, model can understand description fully D3ST
Table - Originial multiwoz data Table - Few SGD data => Random type result meaning description of input is important => If the size of the dataset is small, the language description is much more data- efficient. Language : description, Name : slot name, Random : random word
- Cross domain(leave-one-out) multiwoz data => D3ST is good for zero-shot transfer! Table – DSTC11 track3 organizer baseline Models Multiwoz 2.1 - dev DSTC11 Track3 - dev DST(Trade) 58.3 20.1 D3ST 57.5 40.1 => D3ST contains more features than original text
slot value changed MultiWoz dataset • Original text -> audio, ASR text(user) • Evaluation Method • MultiWoz – DST, POL, NLG • Track3 – DST [1] End-to-End Neural Pipeline for Goal-Oriented Dialogue Systems using GPT-2, ACL 2020 DSTC11 Track3 Models such as GPT-2 end-to-end model[1] are difficult to perform on this task
numerical format change (4 → four) • Time format (12:04 am → 0:04 am) • T5 module • Input : ASR text • Output : Origin text with preprocessing with above rule-based DSTC11 Track3 "Actual":"[str] please get me a ticket for one that leaves at 0:49 am and send me the reference number. [end]", "Source":"[str] please get me a ticket for one that leaves at 12:49 a m a m and send me the reference number [end]"
based + T5) result DSTC11 Track3 "Actual":"[str] please get me a ticket for one that leaves at 0:49 am and send me the reference number. [end]", "Prediction":“[str] please get me a ticket for one that leaves at 0:49 am and send me the reference number. [end]", "Source":"[str] please get me a ticket for one that leaves at 12:49 a m a m and send me the reference number [end]"
preprocessing • Preprocess the input text after (1) according to the d3st format. • description + ASR Error correction result • Model setting • Transformer : T5 – base, large • Input : Preprocessing text • Output : Dialogue state DSTC11 Track3
"src": "0 time of the restaurant booking 1 name of hospital department 2 number of people for the hotel booking 3 number of people booking the restaurant … 34 star rating of the hotel 35 length of stay at the hotel 36 leaving time for the train [user] i need a train leaving from little mountain this thursday. [system] in order to better assist you, may i please have your destination? … [user] please get me a ticket for one that leaves at 0:49 am and send me the reference number.", "tgt": "[states] 6 1 36 0:49 am 29 4:38 pm 21 little mountain 12 12f 18 kings lynn", • Our D3ST format data
• Check token similarity • If token similarity between the database, token is substituted database word DSTC11 Track3 Text origin word similar word similarity i also need a train leaving post falls after 9:33 am going to lignier lignier ligonier 0.9333%
is very powerful for dst task. • However, we could only use the T5 large model as a few epochs. • “We look forward to articles from the participating teams describing their systems. The deadline for paper submissions is November 14th.” • We will experiment above model with many epochs. DSTC11 Track3