The document discusses extracting semantic entities and events from sports tweets to temporally annotate sports videos. Key points: - Tweets about sports events provide free annotations with timestamps that can be used to locally tag segments of event videos. - Challenges include informal language in tweets, extracting named entities like players which are mentioned in varied ways, and detecting micro-events like goals. - Features were developed to detect players based on name variations and contextual words, and detect micro-events based on linguistic cues and burst detection of related tweets. - Evaluating on annotated datasets showed the approach could detect events with up to 86% accuracy but recall for players was only 70%, indicating more work is needed especially for