A natural language processing task that identifies subjective information in text, determining whether the expressed opinion is positive, negative, or neutral. Sentiment analysis enriches multimodal content with emotional context for search and analytics.
Sentiment analysis models classify text into sentiment categories (positive, negative, neutral) or predict a continuous sentiment score. Modern approaches use transformer-based models fine-tuned on sentiment-annotated datasets. The model learns to recognize linguistic cues including word choice, negation, sarcasm, and contextual modifiers that indicate emotional polarity.
Approaches range from lexicon-based methods (VADER) to fine-tuned transformers (RoBERTa-sentiment). Aspect-based sentiment analysis identifies sentiment toward specific entities or attributes within text. Fine-grained sentiment goes beyond 3-class to 5-class or continuous scales. Multilingual sentiment models handle cross-lingual analysis without per-language training. Performance is measured using F1-score and correlation coefficients for regression tasks.