The document discusses a multi-class sentiment analysis approach using hierarchical logistic model trees. It presents research on classifying sentiments into six categories (high positive, positive, low positive, low negative, negative, high negative) using a machine learning technique called Logistic Model Trees (LMT). The methodology involves preprocessing text data using a lexicon called General Inquirer Dictionary and feature extraction before applying the LMT classifier. The goal is to automatically extract sentiment levels expressed in text for applications like improving decision making.