sentence1: sentiment analysis is a research area where does a computational analysis of people ’ s feelings or beliefs expressed in texts such as emotions , opinions , attitudes , appraisals , etc . ( cite-p-12-1-3 ) .
sentence2: sentiment analysis is a ‘ suitcase ’ research problem that requires tackling many nlp subtasks , e.g. , aspect extraction ( cite-p-26-3-15 ) , named entity recognition ( cite-p-26-3-6 ) , concept extraction ( cite-p-26-3-20 ) , sarcasm detection ( cite-p-26-3-16 ) , personality recognition ( cite-p-26-3-7 ) , and more .