a stream of data contributions during a period is collected from a social media data source , the period spanning a broadcast of a content . the stream is analyzed to identify a change in a level of the data contributions during a sub - period of the period . a first time is selected to mark a beginning of the sub - period . a second time is selected to mark an ending of the sub - period . a data fragment is extracted from the data contributions occurring during the sub - period in the stream , the data fragment being descriptive of the content during the sub - period . in a recording of the content , a portion of the recording between the starting time and the ending time is selected as a segment of interest . the recording is annotated with the starting time , the ending time , and the data fragment to identify the segment of interest .