There seem to be a ton of patents that are relevant, and could be combined to predict Apple's patent following at least one of the factors laid out in MPEP 2143.
This patent: "Information management system" US5634051 Issue date: May 27, 1997
The first claim seems that it could be paired with prior referenced patents to suggest the approach Apple employed:
An information storage, searching and retrieval system for large domain archived data of various types comprising:
means for storing a large domain of data contained in multiple source records, at least some of the source records being comprised of individual documents of multiple document types;
means for searching at least a substantial portion of such data based on a search query to identify documents of multiple types responsive to the query; and
means for categorizing documents responsive to the query based on document type, including
means for generating a summary of the number of documents responsive to the query which fall within various predetermined categories of document types.
Additionally, although this patent deals with coordinates the drawings describe a very similar invention to Apple's patent:
"Information search and retrieval with geographical coordinates" US5893093 Issue date: Apr 6, 1999
Claim 1 reads:
An information search and retrieval process using geographical coordinates, which process comprises:
building an index of coordinates for a plurality of text based references, resources or sites, each having a set of said coordinates;
accepting a user inquiry containing a text reference;
converting said text reference specified in said user inquiry to a set of coordinates;
searching against said index of coordinates based on the converted coordinates of said user inquiry reference; and
returning all information retrieved from said searching in a text based format.
The list continues:
"Information retrieval system" US5978803 Issue date: Nov 2, 1999
An information retrieval system, comprising:
a plurality of retrieval servers for performing retrieval processing; and
a retrieval management server for managing operation of said plurality of retrieval servers;
wherein said retrieval management server divides a text base of a retrieval object and relating information regarding the text base into a number of parts based on a size of the text base and loads of the respective retrieval servers and selectively allocates the divided parts of the text base and the relating information corresponding to the divided parts in sets to some or all of said plurality of retrieval servers; and
said plurality of retrieval servers perform information retrieval for the divided parts of the text base allocated by said retrieval management server parallelly to and independently of each other.
And, one more:
"System for storage and retrieval of diverse types of information obtained from different media sources which include video, audio, and text transcripts" US5729741 Issue date: Mar 17, 1998
Claim 1 reads as follows:
A method of processing information contained in different types of media, comprising the steps of:
(a) processing each and every of said different types of media by storing in memory a first, index storage file, which contains a text description of the contents of information contained in said any medium, and an identification of said first, index storage file; and
(b) for each respective medium processed in step (a), analyzing the contents of information of said respective medium, regardless of the type of the subject matter of said contents of information, for the presence of text, and generating a second, text file, that contains all text found in said medium and storing said second, text file in memory in association with said first, index storage file; and
wherein said respective medium comprises a video recording medium containing video and voice information signals associated with a video recorded activity, and a further medium containing a separate transcription of said voice information, and
wherein step (b) comprises processing said voice information signals through an automated voice recognition-to-text conversion mechanism, so as to generate a voice-converted text file, and processing said further medium containing said separate transcription of said voice information to generate a transcribed voice text file, and correlating successive words of said voice-converted text file and successive words of said transcribed voice text file to associate contents of said transcribed voice text file with said video information.