Richard Socher (Salesforce)

Why Unified Multi-Task Models for NLP?

• Multi-task learning is a blocker for general NLLP systems.

• Unified models can decide how to transfer knowledge (domain adaptation, weight sharing, transfer learning, and zero-shot learning).

• Unified AND multi-task models can:

  • More easily adapt to new tasks.

  • Make deploying to production X times simpler.

  • Lower the bar for more people to solve new tasks.

  • Potentially move towards continual learning.

The 3 Major NLP Task Categories

1. Sequence tagging: named entity recognition, aspect specific sentiment.

2. Text classification: dialogue state tracking, sentiment classification.

3. Sequence-to-sequence: machine translation, summarization, question answering.

⇒ They correspond to the 3 equivalent super-tasks of NLP: Language Modeling, Question Answering, and Dialogue.

A Multi-Task Question Answering Network for decaNLP​

Methodology

• Start with a context.

• Ask a question.

• Generate the answer one word at a time by:

  • Pointing to context.

  • Pointing to question.

  • Or choosing a word from an external vocabulary.

• Pointer Switch is choosing between those three options for each output word.

Architecture Design

​decaNLP: A Benchmark for Generalized NLP​

• Train a single question answering model for multiple NLP tasks (aka questions).

• Framework for tackling:

  • More general language understanding.

  • Multi-task learning.

  • Domain adaptation.

  • Transfer learning.

  • Weight-sharing, pre-training, fine-tuning.

  • Zero-shot learning.