Data By the Bay

Supervised machine learning models are extremely powerful and highly useful for processing vast amounts of text. Their applications include sentiment analysis, text classification, topic mining, part of speech tagging, and named entity recognition, among many others. However, supervised models rely heavily on large amounts of annotated data and furthermore require that the annotations be consistent and accurate. In practice, obtaining high quality annotated data, especially with strong inter-annotator agreement, is not always possible for legal and privacy reasons: there are some data that organizations may not be allowed to crowd source. In this talk I propose several methods to help machine learning models get over the hurdle of insufficient labeled data by leveraging a number of computational linguistics techniques. Specifically, focusing on CRF (conditional random field) model for Named Entity Recognition, I discuss how the use of language feature engineering, artificial dataset generation, and post-processing rules can significantly improve model performance, which otherwise suffers from the bottle-neck of insufficient training data. I propose a number of scalable and practical methods that machine learning practitioners can use in situations where obtaining more training data via crowdsourcing is not a viable option.