Category Archives: Research

ACL 2013, Days 5,6

After the conference, there were two days of workshops. I had applied for the BioNLP workshop in which Marinka and I have won the Gene Regulation Network Shared Task (GRN ST).

Throughout the first day of the workshop, researchers presented some general work in the field of BioNLP domain. I met the BioNLP ST organizers – Claire Nedellec, Robert Bossy and Zorana Ratkovic, who are working at INRA, France. Claire wrote a book chapter about the joint extraction of entities and relationships using ontologies from textual data. I was also interested if they continued their work and found out that Zorana recently published a paper that incorporates also coreference resolution (NER->COREF->REL) but in a pipeline manner.

On the first day I also visited a collocated workshop because there were some presentations regarding the extensions of NLP frameworks (e.g. U-Compare, UIMA, GATE) and a showcase how to make UIMA SPARQL interoperable.

In the late afternoon and in the evening I continued the work on my presentation.

The second day was devoted only to the ST presentations and posters. This year it was the third ST and is going to be continued in 2015 with similar tasks. All the tasks were related to some kind of text mining on biological data, for example knowledge base construction, relation extraction, event detection, … Most of the proposed systems extensively depend on syntactic structure of sentences or rules. A well known system – TEES participated in almost all of the shared tasks and also achieved some best results. Furthermore, as TEES is being developed since 2009, also some other competitors used it as a framework to develop their own techniques.

During the poster session I met Marting Krallinger – the organizer of BioCreative IV CHEMDNER challenge. He was enthusiastic about BioNLP STs and told me that there are already around 70 competitors that applied for CHEMDNER. The task of CHEMDNER is to automatically detect chemical compounds from text. The participants will have an option to publish 2-4 pages of their system technical report in the conference proceedings and will also be co-authors of the joint paper in BMC Bioinformatics. Moreover, in that journal there will also be a special issue in which best systems and systems with an interesting methodology will be published.

I gave my talk at 5pm, just before the last talk at the workshop. My slides:

If you do not see the presentation, you can download it from

After all the sessions there was a discussion about further work in the BioNLP ST. The proposal was to publish the source code for all the participating systems, to improve annotations, continue with existing tasks and propose new ones. There will also be a special issue in BMC Bioinformatics for this year’s BioNLP or at least a thematic series within the BMC journal.

In the evening I met with Vasilena and Pavlina (students from Bulgarian association of PhD students) and we went around the city, visited protests and lastly went to a birthday party in a park. Today (saturday) I will continue my trip to Plovdiv, then to Sunny Beach and on Friday I will go home from Varna.

My participation in the protests for Bulgarian rights :):

If you do not see the movie, you can download it from

Some pictures:

ACL 2013, Day 4

This morning’s keynote was given by Assistant Professor in the Department of Psychology at University of Washington, Dr. Chantel Prat. She focuses mostly into cognitive science. The most interesting part of her presentation I think it was a comparison of monolinguals and bilinguals at problem solving. Her findings show that bilinguals perform better on solving novel tasks. But, when both groups of test subjects were tested on already known tasks, the performance of bilinguals remained the same, while the monolinguals improved their performance and achieved the same results as bilinguals.

During the coffee break I visited the Maluuba stand ( They are developing an application similar to Siri and Google Now. They began to develop their product at the same time as the big players, but there are only 25 of them and their product will be integrated into mobile phone systems, TVs, etc. Their focus at ACL is to find new people that would do research for them. I also said hi to the Google people. On monday I already spoke to them and got that nice red glasses :), but today I solved their simple “Research quiz” and got Google bottle – now I obviously need to go running tomorrow morning as I have full equipment with me. Btw, did you know that Google Researchers produce more than 300+ scientific publications per year?


In the first session I attended to A Bayesian Model for Joint Unsupervised Induction of Sentiment, Aspect and Discourse Representations by Angeliki Lazaridou, Ivan Titov and Caroline Sporleder, Joint Inference for Fine-grained Opinion Extraction by Bishan Yang and Claire Cardie and Linguistic Models for Analyzing and Detecting Biased Language by Marta Recasens, Cristian Danescu-Niculescu-Mizil and Dan Jurafsky.

After lunch there was the ACL Business Meeting, where some facts about the conference were introduced. At this year’s ACL there were 987 registrations. There is only one researchers from Slovenia, who is ACL member – I suppose this is Tomaž Erjavec or Darja Fišer. After, there were 15 talks about ACL organization, changes, funding, events, similar conferences, journals, etc. The most of the talks were reports or presentations of similar conferences, where also ACL people cooperate – all of them had also been on my personal conference list.   For NAACL they exposed the problem of financing and this year they published all talks on the internet ( for free and replaced USB proceedings with iOS/Android application, which was a good decision. Then there was a report of EMNLP 2013 and an overview of EMNLP 2014 in Quatar. Others that were presented are IJCNLP 2013/2014, EACL 2014, Coling 2014, ACL-IJCNLP 2015 and IOLING (Internation Olympiad for Linguistics for secondary school). If you would like to coorganize or host the ACL 2016, you are invited to contact

The ACL also controls two journals. The new journal is Transactions of the Association for Computational Linguistics (, which has a submission deadline on the 1st of every month with a review period of 3 weeks. The paper can be accepted, accepted with changes (author needs to resubmit the paper within two monts), rejected with changes (author has possibility to resubmit after 3 to 6 months) and rejected. The novelty is also that these papers can be presented at NAACL or ACL conferences in the form of Paper, Poster or Talk.

The second journal they own is Computational Linguistics, which is one of the top journals in the field and has also a high SCI impact factor. They said that it takes about 2 months to receive first decision about the submitted paper.

Then I attended Syntactic Patterns versus Word Alignment: Extracting Opinion Targets from Online Reviews by Kang Liu, Liheng Xu and Jun Zhao, Mining Opinion Words and Opinion Targets in a Two-Stage Framework by Liheng Xu, Kang Liu, Siwei Lai, Yubo Chen and Jun Zhao and Connotation Lexicon: A Dash of Sentiment Beneath the Surface Meaning by Song Feng, Jun Seok Kang, Polina Kuznetsova and Yejin Choi

After the afternoon coffee break I attended Recognizing Identical Events with Graph Kernels by Goran Glavaš and Jan Snajder, Automatic Term Ambiguity Detection by Tyler Baldwin, Yunyao Li and Bogdan Alexe

The presentation was given by Ms. Li, who works at Disney. She presented their simple workflow TAD, which is able to determine if a specific word is ambiguous or not. Their major problem is to detect opinion about movies from Twitter. For example, the name Skyfall 007 is not ambiguous because if we search twitter with this query, almost all of the answers will be about the movie. But on the other hand, the title of Brave movie is very ambiguous as lots of results have no connection to the movie, e.g. “He is so brave, that …”.

Towards Accurate Distant Supervision for Relational Facts Extraction by Xingxing Zhang, Jianwen Zhang, Junyu Zeng, Jun Yan, Zheng Chen and Zhifang Sui and Sequence Labeling for Determining Opinions in Online Forums by Kazi Hasan and Vincent Ng

They propose a system for opinion mining and present the problem as a sequence labeling. They try to improve classification of ideological debates. Their baseline systems are (Baseline 1): One classifier per each domain, SVM model, each training instance corresponds to a post, that can be positive or negative, feature types are: Basic – unigrams, Sentiment -dependencies, sentiment word counts, Argument – words in a post, (Baseline 2): They add author constraint to the Baseline 1. Further, they propose a system with two constraints: (1) Ideology Constraint (IC) – applicable for the same author, but for different domains. IC motivation: anti-abortion person is likely to be anti-Obama person. (2) User Interaction Constraint (UC): Regularities between interactions: a sequence of posts for which they use CRFs. They evaluated on 4 datasets: Abortions support, Gay rights, Obama support, Marijuana legalizations, and showed significant improvements over the baseline systems.

After this last session, the Lifetime Achievement Reward was given to Jerry Hobbs, who then had a very interesting talk about history and “future” of NLP. We may have some useful system “in the next 10 years”. With this event, the ACL 2013 finished and now the two days of workshops will begin.

If you do not see the movie, you can download it from

For dinner I used Metro (btw., there is really nice and clean Metro in Sofia, uncomparable to some “famous” EU cities) to get to City Center Sofia. There I went to KFC and for a cheeseburger in MacDonald’s. If I define a cheeseburger as a one unit a person can eat and compare prices between Slovenia and Bulgaria, I can conclude that there are no significant differences. In Slovenia, 1 cheeseburger is 1 EUR and in Sofia 1 cheeseburger is 1,99BGN (=cca. 1EUR).

Now I need to make my presentation …

Some pictures:


ACL 2013, Day 3

In the morning there was a keynote given by Lars Rasmussen who got his PhD at the University of Edinburgh, then worked in his own start-up that was bought by Google. At Google he was then working on Google Wave and now he is employed at Facebook, where he is working on Facebook graph search using natural language interface. In his keynote he presented the new Facebook NLP graph search with some interesting queries, e.g. “Photos of my friends who knit”, “Photos of my friends from national parks”, “Restaurants in Sofia by locals”, etc.. He also pointed out some notions of problems in understanding the system by Facebook employees and by public. For example, how would you select people who knit? Their idea was to support obvious query “People who like Knitting”, but public generated questions like “People who knit”, “knitters”, etc. He also presented the development of the system since the beginning of 2 years ago and gave a high level architecture overview. Next to the obvious NLP parts, they also introduce “de-sillyfication” method before doing further NLP processing. Interestingly, for more detailed questions at the end of the talk there were also some engineers from his team that could answer more technical questions.

In the first session I attended to the following talks: A Random Walk Approach to Selectional Preferences Based on Preference Ranking and Propagation by Zhenhua Tian, Hengheng Xiang, Ziqi Liu and Qinghua Zheng, ImpAr: A Deterministic Algorithm for Implicit Semantic Role Labelling by Egoitz Laparra and German Rigau and Cross-lingual Transfer of Semantic Role Labeling Models by Mikhail Kozhevnikov and Ivan Titov

During the lunch break I visited Pavlina Ivanova and her friend from the association of doctoral candidates in Bulgaria. We had a really nice talk and tomorrow evening we are planning to go around the Sofia center.

In the afternoon I attended to:

Argument Inference from Relevant Event Mentions in Chinese Argument Extraction by Peifeng Li, Qiaoming Zhu and Guodong Zhou

Fine-grained Semantic Typing of Emerging Entities by Ndapandula Nakashole, Tomasz Tylenda and Gerhard Weikum

The talk was about how to detect emerging entities that will become popular. For Out-of-KB Entity Detection, they focused on noun phrases, that can represent: a class/general concept and not an entity, already known within a KB, a new name for an old entity in KB, a new entity, unknown in DB. They use PATTY, which has a collection of 300.000 synsets, e.g. PATTY phrase <musician> released <album>, <music band> released <album>, <company> released <product>. Using PATTY, they propose a probabilistic weight model P(t1,t2|p) = P(t1,t2|p)/P(p), where <*> p <*>. If one of the entities is known in a DB, the IMENOVALCE can also be P(p, t2).

Embedding Semantic Similarity in Tree Kernels for Domain Adaptation of Relation Extraction by Barbara Plank and Alessandro Moschitti

Their task is to find binary ACE-2004 (newspaper and broadcast news) type relations. What happens when you change the domain? They propose a term generalization approach and a general syntactic structure. They crawled a pivot corpus from WWW. They have idea to use standard syntactic tree kernel, i.e. similarity between two trees is counting the number of the same subtrees. Issue here: there are similar syntactic structure, but the leaves differ, e.g. mother of two VS. governor from Texas have similar subtrees. So they tried to employ semantic syntactic tree kernel, which allows soft matches between terminal nodes. How is this good for domain adaptation? They focus on two types of semantic similarities: (1) Brown word clusters, they induced 1k clusters from ukWc corpus (Baroni et al.) and (2) — i forgot what — :). Their system workflow looks as follows: Raw Text-> (Charniak) Parser-> Parse Trees with entities-> Tree Kernel based SVMs-> Multi-class classification.  They also tested within ACE datasets – train on one, test on other (the thing I wanted to ask :):) because I did the same thing for coreference resolution across different corpora), and as expected, results were lower by about 10%. Interestingly, there is almost no related work on DA (domain adaptation) on RE (I think it is the same for coreference resolution).


During the coffee break I talked to the Baidu people, which say that Baidu is the largest search engine in the world (Maybe, but I am not completely sure about that…). I also found out that “Baidu” is a term from a Chinese poem and means something like: “You search for something and it suddenly appears”. Baidu is also this year’s biggest ACL sponsor and the organizers said we should look a little on sponsor pages, so you as a reader should also gaze a little bit at the following photos:

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In the last session I attended to: Smatch: an Evaluation Metric for Semantic Feature Structures by Shu Cai and Kevin Knight, Variable Bit Quantisation for LSH by Sean Moran, Victor Lavrenko and Miles Osborne, Context Vector Disambiguation for Bilingual Lexicon Extraction from Comparable Corpora by Dhouha Bouamor, Nasredine Semmar and Pierre Zweigenbaum and lastly The Effects of Lexical Resource Quality on Preference Violation Detection by Jesse Dunietz, Lori Levin and Jaime Carbonell

In the last talk the authors have also presented some useful systems that I can use for pre-processing: VerbNet (, SemLink (, SENNA (

In the evening there was a Banquet (aka. dinner) at Sheraton Hotel. I socialized a bit more and found out there are a lot of people from Industry, just observing the conference and some of them having no papers at all. I got to know people from Google (they have quite a lot of papers), Intel, Nuance (Siri uses their speech recognition if you did not know, very successful company), Sony, Microsoft, Nice Systems, …

Some shots:



If you cannot see the videos, you can download them from URLs, and