Table of Contents Introduction Text Preprocessing Tasks Models Perplexity Introduction Text Preprocessing Character-level tokenization Word-level tokenization Subword tokenization Stopwords Batching Padding Unsupervised Pre-Training Autoregression BERT loss Tasks Text Classification Named Entity Recognition Question Answering Summarization Translation Text Generation Text Preprocessing Text preprocessing is an essential step in NLP that involves cleaning and transforming unstructured text data to prepare it for analysis. Some common text preprocessing techniques include: