2、计算机信息检索05.3.ppt

计算机信息检索
Computerized Information Retrieval
(工程硕士)


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信息检索词汇(terms)
Information retrieval (IR)
Information access (obtain)
Information search (look for)
Information searching (look for)
Information seeking (focus on users, active)
locate
hit
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1. 信息检索发展阶段
●手工操作(manual)
●计算机化(computerized)
●网络化(networked)
●智能化(intelligentized)
●认知化(cognized)
What’s searching like?
“Finding a needle in a haystack”
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2. 主要检索系统类型
联机检索(online search)
脱机检索(offline search)
光盘检索(CD search)
网络检索(Interne/Web search)
全球数字图书馆系统(digital global system)
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通信网络联机检索中心
检索终端
数据库
联机检索(online search)
The process of locating specific pieces of info from one or more databases that reside on puters(hosts). The search is a true interaction between you and search system.
主机
Feature: interaction, real time
remote, Direct
WAN
微机
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Online databases
Features
¨ A test-bed for early IR experiments & development
¨ The showcase of IR technology (, relevance retrieval) until the , the Web became popular
¨ A laboratory for acquiring information retrieval skills
IR capability
¨ Covers virtually every type of database structures
¨ Implement all different retrieval models and techniques
-----Hahn
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OPACs
Features
¨ An extension of MARC records
¨ A product of library automation
¨ A bibliographic database of library resources for an institution at various levels, , local, regional, national
IR capability
¨ Easy to browse (resemble shelf structure)
¨ Based on well-established hierarchical database structure
¨ May provide sophisticated searching capabilities but users may not benefit from them
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光驱
检索终端
微机
光盘检索(CD search)
光盘单机检索
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检索终端
局域网
服务器
光驱
LAN
微机
tower
jukebox
光盘联机检索(CD online)
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CD-ROMs
Features
¨ Online databases in CD-ROM medium
¨ Portability
¨ Cheaper & more convenient access until the Web es the gateway for CD-ROM access
¨ Noticeable problem in updating the database
¨ Hypertext or hypermedia is heavily used in CD-