NLP Tasks


Here we summarize some natural language processing tasks. Compare their semantic levels, difficulty, and similarity. We rank and group them into a table.

NLP Tasks

Task Input Type
Word tagging    
Word segmentation sentence tagging/generation
Shallow syntax - Chunking sentence tagging/generation
Named entity recognition sentence tagging/generation
Part-of-speech tagging sentence tagging/generation
Semantic role labeling sentence tagging/generation
Sentence parsing    
Constituency parsing sentence parsing/generation
Semantic parsing sentence parsing/generation
Dependency parsing sentence parsing/generation
Text classification    
Sentiment analysis sentence classification
Text classification sentence or doc classification
Text pair matching    
Semantic textual similarity sentence or doc pair classification/regression
Natural language inference sentence or doc pair classification
Text information extraction or analysis    
Temporal Processing sentence or doc tagging/generation
Coreference resolution sentence tagging/classification
Word Sense Disambiguation sentence or doc ranking/matching/classification
Relation Prediction sentence or doc classification/generation
Information Extraction sentence tagging/generation
Text generation    
Language modeling sentence or doc generation
Machine translation sentence generation
Simplification sentence generation
Summarization doc generation
Dialogue sentence seq generation
Question answering sentence or doc generation/span prediction/matching/ranking/classification


The main NLP tasks include word level tagging, sentence level parsing, text classification, text pair matching (classification, ranking, etc), fine-grained disambiguation or information extraction, and generation.


  1. We can group tasks according to their semantic-level requirements.
  2. We can unify most tasks into generation.