Internet Surfing Basics
CHUAN HONG, PLANT PATHOLOGIST
|
Internet Surfing Basics CHUAN HONG, PLANT PATHOLOGIST |
| Introduction | Search Tools | Search Strategies |
| Search Tips | Evaluation of Web Resources | |
INTRODUCTION
Why a Digital Nursery Workshop?
The goals of this lecture and workshop
|
The Internet, The WWW, and Netscape Finding Information on the Internet - A Tutorial Two Internet Addresses - Internet host address and Internet Protocol address. An Internet host address consists of three basic parts:
The last part of the address, first level domain, has a unique name that identifies a type of organization (in the United States) or a country (outside of the United States). Examples of the major first level domains of the Internet for organizations in the United States include:
The first level domains of the Internet for organizations in countries other than the United States are listed at http://www.ics.uci.edu/pub/websoft/wwwstat/country-codes.txt. Internet protocol (IP) address The IP address is a numeric address that looks like this: 140.160.0.0 IP addresses are the same as the Internet address except that they are in numeric form and the order for identifying hosts is reversed. |
The four basic tools for searching the Internet are search engines, subject directories, subject guides, and specialized databases.
Search Engines
A search engine is a searchable database of Internet files collected by a computer program (called a wanderer, crawler, robot, worm, spider). Indexing is created from the collected files, e.g., title, full text, size, URL, etc. There are no selection criteria for the collection of files.
A search engine might well be called a search engine service or a search service. As such, it consists of three components:
There are two major types of search engines:
A subject directory is a service that offers a collection of links to Internet resources submitted by site creators or evaluators and organized into subject categories. Directory services use selection criteria for choosing links to include, though the selectivity varies among services. Most directories offer a search engine mechanism to query the service.
Comparison of the Four Search Tools
|
Wildcards: Some search engines allow the use of "wildcard" characters in search statements. Wildcards are useful for retrieving variant spellings (eg. color, colour) and words with a common root (eg. psychology, psychological, psychologist, psychologists, etc.). Wildcard characters vary from one search engine to another, the most common ones being *, #, and ?. Some search engines permit only right truncation (eg. psycholog*), while others also support middle truncation (eg. colo*r). For example, Alta Vista supports both right and middle wildcards.
Case Sensitivity: Some search engines treat upper and lower case letters differently. For example, if you give a word with an upper case letter, Alta Vista searches only for that word with an upper case letter. If you use lower case, Alta Vista retrieve upper and lower cases. Try Ornamental and ornamental at Altavista.
Relevance Ranking: All of the search engines covered in this workshop use an algorithm to rank retrieved documents in order of decreasing relevance. Consequently, it is often not necessary to browse through more than the first few pages of results, even when the total results number in the thousands. Furthermore, some search engines (eg. AltaVista) allow the searcher to determine which terms are the most "important", while others (Excite, Infoseek) have a "more like this" feature that permits the searcher to generate new queries based on relevant documents retrieved by the initial search. These features are discussed in more detail in the following section of this document.
Ctrl-F: After following a link to a document retrieved with a search engine, it is sometimes not immediately apparent why the document has been retrieved. This may be because the words for which you searched appear near the bottom of the document. A quick method of finding the relevant words is to type Ctrl-F to search for the text in the current document.
Bookmark Your Results: If you are likely to want to repeat a search at a later date, add a bookmark (or favorite) to your current search results.
| back | | Hampton
Roads AREC | | Virginia Agricultural Experiment
Stations |
Comments to chhong2@vt.edu
Hampton Roads Agricultural Research and Extension Center
1444 Diamond Springs Road
Virginia Beach, VA 23455