Overview
Also known as opinion mining, sentiment analysis determines whether a piece of writing is positive, negative, or neutral. It can also detect specific emotions like anger, joy, or sadness.
Levels of Analysis
- Document Level: Determining the sentiment of an entire review or article.
- Sentence Level: Analyzing individual sentences.
- Aspect-Based: Identifying sentiment towards specific features of a product (e.g., 'The battery life is great, but the screen is dim').
Techniques
- Lexicon-based: Using dictionaries of words with assigned sentiment scores.
- Machine Learning: Training classifiers (like SVMs or Naive Bayes) on labeled datasets.
- Deep Learning: Using LSTMs or Transformers for more nuanced contextual understanding.
Applications
- Monitoring social media for brand reputation.
- Analyzing customer feedback and reviews.
- Market research and political polling.