responsive to determining that {HEAD ~ the media content} is interest to {TAIL ~ the user}, indexing a media database with the extracted semantic text features 
responsive to determining that { HEAD ~ the media content } is interest to { TAIL ~ the user } , indexing a media database with the extracted semantic text features
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH