Unsupervised NLP

Unsupervised learning methods and techniques in Natural Language Processing

Unsupervised NLP

Unsupervised learning in NLP focuses on discovering patterns and structures in text data without labeled examples.

Topic Modeling

Latent Dirichlet Allocation

  • Probabilistic model
  • Document-topic distribution
  • Topic-word distribution
  • Hyperparameter tuning

Non-negative Matrix Factorization

  • Matrix decomposition
  • Topic coherence
  • Interpretability
  • Implementation strategies

Text Clustering

Document Clustering

  • K-means clustering
  • Hierarchical clustering
  • DBSCAN
  • Evaluation metrics

Semantic Clustering

  • Embedding-based clustering
  • Semantic similarity
  • Cluster interpretation
  • Applications

Word Embeddings

Unsupervised Word Representations

  • Word2Vec
  • FastText
  • GloVe
  • Training strategies

Contextual Embeddings

  • BERT-based embeddings
  • Auto-encoding models
  • Contrastive learning
  • Fine-tuning approaches

Document Similarity

Similarity Metrics

  • Cosine similarity
  • Euclidean distance
  • Jaccard similarity
  • Semantic similarity

Applications

  • Document deduplication
  • Content recommendation
  • Plagiarism detection
  • Information retrieval

Pattern Discovery

Collocation Detection

  • Statistical measures
  • Association rules
  • Phrase mining
  • N-gram analysis

Event Detection

  • Temporal patterns
  • Burst detection
  • Topic evolution
  • Trend analysis

Representation Learning

Auto-encoders

  • Text auto-encoders
  • Variational auto-encoders
  • Sequence-to-sequence
  • Reconstruction quality

Self-supervised Learning

  • Masked language modeling
  • Next sentence prediction
  • Rotation prediction
  • Contrastive learning

Best Practices

  1. Data preprocessing
  2. Model selection
  3. Evaluation strategies
  4. Hyperparameter tuning
  5. Result interpretation

Common Challenges

  • High dimensionality
  • Sparsity
  • Scalability
  • Interpretability
  • Evaluation

Tools and Libraries

  • Gensim
  • scikit-learn
  • SpaCy
  • NLTK
  • Transformers
  • Text Preprocessing
  • Dimensionality Reduction
  • Evaluation Metrics
  • Visualization Techniques