Final Report | Stage 7 | The final report

Anand Panchbhai | A Neural QA Model for DBpedia | GSoC’19

Welcome to the final report of my 2019 GSoC project, If you are a newbie and want to know more about the journey of this project- do read it from the very begining else lets dive straight in.

If you wanna have a look at code please find it in the following link: Github Repository: https://github.com/dbpedia/neural-qa/tree/working-gsoc-anand

The whole work was added as a single pull request whose link is as follows: https://github.com/dbpedia/neural-qa/pull/14.

You can contact me at: panchbhai1969[at]gmail[dot]com

This page is 3 divided into parts:

• Introduction
• Stage Wise Explaination
  • Comparision between what was proposed and what was done.
  • New innovative ideas introduced in that stage and link to detailed information about that idea
  • Link to corresponding code and blog
  • What is not done.
• Future aspects of this project

The Meeting Documents that was maintained for the whole duration of GSoC project can be accessed through: Minutes of the Meeting

We will try to keep it short and simple, lets begin.

Introduction

With booming amount of information being continuously added to the internet, organising the facts becomes a very difficult task. Currently DBpedia hosts billions of such data points and corresponding relations in the RDF format.

Extracting data from such data sources requires a query to be made in SPARQL and the response to the query is a link that contains the information pertaining to the answer or the answer itself.

Accessing such data is difficult for a lay user, who does not know how to write a query. This proposal tries to built upon a System :(​ https://github.com/AKSW/NSpM/tree/master ​) — which tries to make this humongous linked data available to a larger user base in their natural languages(now restricted to English) by improving, adding and amending upon the existing codebase.

The primary objective of the project was to be able to translate any natural language question to a valid SPARQL query.

Stage Wise Explaination

The whole project was divided into 7 stages according to the proposal submitted. The stage structure is maintained for the ease of grasping the movement of the project through the timeline:

Stage 0 | Community bonding period (May 6 - 27, 2019)

To understand the current code base in detail, ponder upon all possible improvements and discuss with the mentors.

• Get to know the mentors and the community: listen, communicate and learn. [ Done ]
• Learn about the intricacies of the coding practices followed by DBpedia, which include coding, community relations as well as version control practices. [ Done ]
• Go through research paper on the relevant field to come up with good strategies to handle the problems at hand. (Learn from what has already been done in this field). [ Done ]
• Understand the people you are working with, finalize all required channels of communication. [ Done ]

Coding period (May 27, 2019 - August 19, 2019)

Stage 1 | Improvements (Based on current state of research): (May 27, 2019 - June 4, 2019)

The first stage will mainly focus on fixing all issues in the code base to create a proper playing ground for future research endeavour that the project intends to take.

• Fixing all the deprecated parts of the code to ensure the usability of the code [ Done ]

  • The issues that were fixed are:

    Issues	URL	Fixed
    Zero division error	(https://github.com/dbpedia/neural-qa/issues/8)	Yes
    Adding progress bar for loops in generator.py:	(https://github.com/dbpedia/neural-qa/issues/9)	Yes
    Tensorflow version	(https://github.com/dbpedia/neural-qa/issues/11)	Yes
    Fix PIPELINE	(https://github.com/dbpedia/neural-qa/issues/12)	Yes

• Improve the readme to ensure better understanding of the project to new developers and yourself. [ Done ]
  • Readme fixes: [https://github.com/AKSW/NSpM/pull/21]
• Use accuracy measures other than BLEU like F-score (Do initial setup for all of them) [ Completed in stage 3 ]
  • BLEU and accuracy is implemented as part of the NMT model.
  • F1 Score was implemented using GERBIL (Micro-F1 was used for all the tests)

    • As part of establishing a system for using GERBIL the following projects had to be setup:

      Issues	URL
      GERBIL	https://github.com/dice-group/gerbil
      Django WebApp	https://github.com/panchbhai1969/gerbil-client-django-webapp

    • Both contain instructions to run the repositories.

  • The blog to the corresponding coding stage is: https://anandpanchbhai.com/A-Neural-QA-Model-for-DBpedia/WeekSeven
• Setting up a way to evaluate the model against the QALD benchmark. [ Done ]
  • GERBIL setup [ Done ]

Stage 2 | Where do we stand today? (June 5, 2019 - June 10, 2019)

This stage will shed a light on where we stand and forge a concrete path this project will take. (as according to Aman’s blog, extensive work couldn’t be done in compositionality for complex QA because of the time constraints of the project).

• Test the existing model on compositionality for complex QA. [ Done ]
  • Test were run on the following templates: https://github.com/dbpedia/neural-qa/blob/master/data/GS-v3.csv
• Accessing the performance of the model in the previous point. [ Done ]
  • The BLEU score on the test split reached ~95 units.
• Evaluate and adjust the model to gain maximum performance. [ Done ]
• Discuss the shortcomings and what to do next, also involving the ideas suggested in the previous sections of the proposal. [ Done ]

Stage 3 | Generalised question making framework for compositionality (June 10, 2019 - June 23, 2019)

• Generating domain independent templates to minimize burden on the end user for both complex and simple QA. (As per the discussion in the previous stage ) [ Done ]
  • It was a rather complicated task, it is elaborately written as one of my post: https://anandpanchbhai.com/A-Neural-QA-Model-for-DBpedia/WeekSix

Stage 4 | Let’s make it all natural (June 28, 2019 - July 5, 2019)

Making questions more natural, it was a rather interesting question. I used a mechanism similar to page rank used by google.

• The major idealogy used was:

  Hypothesis: Relevance of template can be determined by the popularity of the corresponding answers.

• Popularity can be loosely related to the number of page views and the page view values were extracted from SubjectiveEye3D paper.
• Again the detailed information of the methodology can be found at: https://anandpanchbhai.com/A-Neural-QA-Model-for-DBpedia/WeekSeven

Evaluation 1: June 24 - 28, 2019

Stage 5 | Finishing Question Making (July 6, 2019 - July 21, 2019)

This stage will be the last stage that tries to address the problems related to template generation for simple and complex QA.

• Current complex QA model doesn’t understand when to add a new variable in the query, need to devise a method to make it more aware. Discuss and find a way to handle these points in the model. (Some of my ideas were mentioned in the previous sections of the proposal ) [Done ]
  • This aspect of the code was optional in the proposal
  • The overall direction of the project is analysisng the compositionality capability of the code.
  • During the previous stage a generalized mechanism was built to generate question with variable depth as per the requirement of the user. On changing the depth from 1 to 2 that is the case of compositionality the model was able to perform well, this can be inferred from the results obtained in the later stages.
  • Future scope of the project can include more tesing on the capbility of the model to determine when new variables need to be used by increasing the depth further. [Future Scope ]

Evaluation 2: July 22 - 26, 2019

Stage 6 | The Grid Search (July 27, 2019 - August 10, 2019)

Evaluating the performance of the model by tweaking the attributes for the NMT model to give maximum performance using the training dataset generated in the previous stages.

• Grid Search [ Done ] -The corresponding chart is as follows: Grid Search
  • The best results obtained were:
    • BLEU = ~93
    • Accuracy = 63
  • Details results can be found in the blog: https://anandpanchbhai.com/A-Neural-QA-Model-for-DBpedia/WeekFifteen.html
• Discussion with the mentors. [ Done ]
  • Most of the experiments were done on Eukaryotes. The grid search was done on the hyperparameters of the model as well as some embeddings.
  • On using embeddings a boost in performance was observed the best results above incooperated those experiments too.
  • We then started working on other ontologies too, namely Person. The results were interesting and can be found at: https://anandpanchbhai.com/A-Neural-QA-Model-for-DBpedia/WeekFifteen.html
• Code cleanup (BUFFER) [ Completed in stage 7 ]

Stage 7 (August 11, 2019 - August 18, 2019)

• Code cleanup (BUFFER) [ Done ]
• Discussion for future scope of the project [ Initial Discussion was done ]

Students Submit Code and Final Evaluations: August 19 - 26, 2019

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Future aspects of this project

• The mentors and I decided to continue to work on the project for a few more months to get enough results to publish a paper.
• The major aim being able to show the efficancy of current nmt models in translating compositionality based questions to proper SPARQL query.
• The work to be done includes [Future Scope]:
  • Running more experiments
  • Comparing with the current state of the art
  • Working on variable awareness
  • Testing a fully trained model on QALD and LC-QuAD

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