The document discusses mining user opinions from hotel reviews through sentiment analysis and data mining techniques. It describes how sentiment analysis can be used to identify aspects of hotels that customers like or dislike in order to improve sales and margins. It also discusses some limitations of machines in sentiment analysis and examples. The document then outlines the data mining process used, including data cleaning, preprocessing with part-of-speech tagging and sentiment lexicon tagging. It finds issues with sentiment lexicon coverage and proposes rule-based and relation-based mining as solutions. Validation results show 84% precision and 78% recall for the sentiment analysis techniques.