I am deeply indebted to Dr. Michael Berry, my major advisor, for his kind guidance and support. I also thank Dr. Susan Dumais, director of the Information Sciences Research Group at Bellcore, for her technical advice. In addition, she graciously allowed us
Chapter1
Introduction
Asstoragebecomesmoreplentifulandlessexpensive,theamountofinformationre-tainedbybusinessesandorganizationsislikelytoincrease.Searchingthatinformationandderivingusefulfacts,however,willbecomemorecumbersomeunlessnewtech-niquesaredevelopedtoautomaticallypartitionthedataintosetssmallenoughforahumantounderstand.
1.1MotivationandGoals
RichardWurman,inhisbookInformationAnxietyreportsthreestartlingfacts:“Approximately9600differentperiodicalsarepublishedintheUnitedStateseachyear,”
“Theamountofavailableinformationdoublesevery veyears;itwillsoondoubleeveryfour,”and
“Thenumberofbooksintoplibrariesdoubleseveryfourteenyears[Wur89].”Unfortunately,althoughtheamountofinformationavailableisgrowingatanexponen-tialrate,ourabilitytosearchthatinformationandderiveusefulfactsisdiminishing.
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