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网 络 免 费 资 源 指 南

网 络 免 费 资 源 指 南. 图书馆信息中心 张茵. The Internet is a vast source of information It connects millions of computers around the world - computers belonging to all sorts of people and organisations. All these computers hold information, some of which is free for everyone to access and use.

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网 络 免 费 资 源 指 南

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  1. 网 络 免 费 资 源 指 南 图书馆信息中心 张茵

  2. The Internet is a vast source of information It connects millions of computers around the world - computers belonging to all sorts of people and organisations. All these computers hold information, some of which is free for everyone to access and use. Perhaps some of it could help you? Information comes from a wide variety of sources such as: The Internet is a vast source of information It connects millions of computers around the world - computers belonging to all sorts of people and organisations. All these computers hold information, some of which is free for everyone to access and use. Perhaps some of it could help you? Information comes from a wide variety of sources such as: 资源来源

  3. 如何搜索到需要的资源 • Let‘s look at some tools for searching the Internet 搜索工具 • There are three main types of Internet search tools, all of which offer something slightly different. You will need to understand more about these tools before you can decide which is most suitable for your purposes • Search Engines搜索引擎 • Web Directories 元搜索引擎 • Specialist Search Tools专业搜索工具

  4. Search Engines • Search engines aim to help you search as much of the Web as possible • Perhaps the best-known search engine is: • Google最常用的搜索工具 • Search engines work by sending out special Web-harvesting software to Web sites around the World to automatically create a huge index that lets you search millions (if not billions) of Web pages. • Most of the famous search engines are run by commercial companies in the USA. • Pros 优点 • Search engines are useful if you want to find a very precise piece of information 具体信息 • Will find something on every subject imaginable 主题广泛 • Cons 缺点 • Can give you too many results –time consuming to sort through 耗时 • Can return lots or irrelevant or inappropriate information 过多无用信息

  5. WEB DIRECTORIES • Web directories aim to help you look through (or browse) many thousands of Web sites under a series of subject headings • Two well known Web directories: • Yahoo • DMOZ Open Directory • Most are run commercially and use volunteers or hired-editors to select the Web sites and arrange them into subject lists. Many are USA-based. • Pros 优点 • The subject lists mean you don’t have to think up search terms 提供主题 • They cover a very wide range of subjects: so good if you want popular sites as well as serious ones 信息广泛 • Cons 缺点 • You may find lots of the sites are irrelevant to your needs –directories try to be "all things to all people" and so list all kinds of sites • They list many thousands of subject headings and Web sites so it can be time-consuming to find a useful one.

  6. SPECIALIST SEARCH TOOLS • Specialist Internet search tools aim to help a particular audience find high quality Web sites for their particular needs. 针对具体需要 • They are often created by specialist organisations (eg. universities, governments, professional groups) who often employ qualified subject experts to select and organise websites under subject headings, and write descriptions of the sites. • PROS 优点 • Good if you need trustworthy results for serious work or research 有效信息 • You get fewer, but more relevant results, as the subject specialists have filtered out a lot of the inappropriate sites 高度相关性 • CONS 缺点 • If you are not their intended audience they probably won‘t give you relevant results 接入限制 • They may bring back too few results, if you are looking for very specific information or for popular information 信息过少

  7. 专业数据库 • 商业数据库 需要购买才能获取全文,但可以免费获取文摘信息 EI、SCI、SPRINGER，PROQUEST • 免费数据库 Doaj, Pubmed, Hirewire Press

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