64. A method of indexing and searching timed media files, as recited in claim 63 , wherein said calculation of major topic shifts includes chunking language contained within the timed media file into short segments or sentences; and said lexical cohesiveness function includes the pair-wise comparison of segments to determine a relatedness value between each pair of segments.
64. A method of indexing and searching timed media files, as recited in claim 63 , wherein said calculation of major topic shifts includes chunking language contained within the timed media file into short segments or sentences; and said lexical cohesiveness function includes the pair-wise comparison of segments to determine a relatedness value between each pair of segments. 72. A method of indexing and searching timed media files, as recited in claim 64 , wherein said topic shifts are calculated via an iterative process including calculating a sequence of lexical cohesiveness values, where each of said lexical cohesive values is calculated as if there were a topic shift at a particular potential topic shift location; and inserting a topic boundary at the potential topic shift location with the maximum calculated lexical cohesiveness value.