Friday, August 31, 2012

Internet Lecture # 5


What is a search engine?

Basically, a search engine is a software program that searches for sites based on the words that you designate as search terms. Search engines look through their own databases of information in order to find what it is that you are looking for.

How Do Search Engines Work?

Please note: search engines are not simple. They include incredibly detailed processes and methodologies, and are updated all the time. This is a bare bones look at how search engines work to retrieve your search results. All search engines go by this basic process when conducting search processes, but because there are differences in search engines, there are bound to be different results depending on which engine you use.
  1. The searcher types a query into a search engine.
  2. Search engine software quickly sorts through literally millions of pages in its database to find matches to this query.
  3. The search engine's results are ranked in order of relevancy.

How to Search the Internet Effectively
Internet search sites can search enormous databases of Web pages, using titles, keywords or text. You can maximize the potential of search engines by learning how they work, and how to use them quickly and effectively.
The challenge is to ask your question the right way, so that you don't end up overwhelmed with too many search results, underwhelmed with too few, or simply unable to locate the material that you need. As with most skills, practice makes perfect!

Getting Started
Before doing a search, it's important to define your topic as completely as possible. Write down exactly what information you're looking for, why you're looking for it, and what you're not looking for. This will help you to discover the best keywords for your search.

Keywords
With the exception of search engines such as AskJeeves.com, which will take questions in the form of actual queries, most work best if you provide them with several keywords. So how do you determine which keywords will work best?
Most users submit 1.5 keywords per search, which is not enough for an effective query - the recommended maximum is 6 to 8 carefully chosen words, preferably nouns and objects. Avoid verbs, and use modifiers only when they help to define your object more precisely - as in "feta cheese" rather than just "cheese."
Now you have your keywords. How do you enter them into the search engine?

Use of Phrases
Your most powerful keyword combination is the phrase. Phrases are combinations of two or more words that must be found in the documents you're searching for in the EXACT order shown. You enter a phrase - such as "feta cheese" - into a search engine, within quotation marks.
Some searches provide specific options for phrases, while others don't allow them at all; but most will allow you to enter a phrase in quotation marks. Check the "Help" files of the search engine you're using to be sure what it accepts.

Punctuation and Capitalization
Most search engines are insensitive to case: you can type your queries in uppercase, lowercase, or a mix of cases. If you use lowercase, most engines will match on both upper and lower case; so for general searches, lowercase is the safest form to use.

Boolean Basics
"Boolean" searching (named after George Boole, the 19th-century mathematician who founded the field of symbolic logic) is a powerful technique that can narrow your search to a reasonable number of results, and increase the chance of those results being useful. Boolean searches are simple to learn and tremendously effective. The three most commonly used Boolean commands (or "operators") are AND, OR and AND NOT.

AND means "I want only documents that contain both/all words." For instance, the search "London" AND "Big Ben" AND "Buckingham Palace" AND "Trafalgar Square" would return only documents that contained all four keywords or phrases. AND is the most frequently used Boolean command.

OR means "I want documents that contain either word; I don't care which." The query "London" OR "Big Ben" OR "Buckingham Palace" OR "Trafalgar Square" would return all documents that contained even one of these four keywords or phrases. Use OR to string together synonyms; be careful about mixing it with AND.

AND NOT means "I want documents that contain this word, but not if the document also contains another word." The query "London" AND "Big Ben" AND NOT "Buckingham Palace" would return documents that include London and Big Ben, but not those that also include Buckingham Palace. Remember that AND NOT only applies to the word or phrase that immediately follows it.

Most search engines support the AND NOT command.  It is sometimes called BUT NOT or NOT, and is sometimes indicated by placing a minus sign (-) before the term or phrase to be removed.  (Check the search tips of the engine you're using to see which form of AND NOT it accepts). Before you apply AND NOT, see what results you get from a simpler search. AND NOT is a great way to weed out results you don't want, such as pornography.

Quick Tips
  • Use nouns as query keywords. Never use articles ("a," "the"), pronouns ("he," "it"), conjunctions ("and," "or") or prepositions ("to," "from") in your queries
  • Use 6 to 8 keywords per query
  • Where possible, combine keywords into phrases by using quotation marks, as in "solar system"
  • Spell carefully, and consider alternate spellings
  • Avoid redundant terms
  • Check the "Help" function of the particular search engine you're using, since they all have their own quirks and preferences
A successful Internet search can take several tries. But remember: it's estimated that there are between 200 and 800 million documents online - with no master system for organizing this information! No wonder effective searches take knowhow, patience and ingenuity.

Saturday, August 18, 2012

2012 Second Grading Lecture 3


HYPERLINK

          This is a connection between an element in a hypertext document, such as a word, phrase, symbol, or image. The user activates the link by clicking on the linked element, which is usually underlined or in a color different from the rest of the document to indicate that the element is linked. With hyperlinks, one can easily move through a cast amount of information by jumping from one Web page to another.

      By clicking the Autos command, it will jump to another page which shows the content of Autos. Hyperlink work in this way as it shows connection from home page to sub page.


THE WEB BROWSER

THE WEB BROWSER

          A web browser is a software program that enables one to access and view the Web pages. Web browser software is built on the concept of hyperlinks. This is used in jumping from one link to another in whatever order it chooses.       

          The three most popular browsers currently available are Microsoft Internet Explorer, Mozilla Firefox and Netscape Navigator. Most computers allow you to connect easily using either browser but for our discussion here, we will be using the Internet Explorer. There are various ways to open the Internet Explorer. Two of these are:

1.   Double-click the Internet Explorer icon on your desktop.
2.   Open the Start menu and select Internet Explorer from your list of programs.
                                                                                                  
Most web browsers are also capable of downloading and transferring files, providing access to newsgroups, displaying graphics embedded in the document and playing audio and video files associated with the document.

History of Browser

          On January 1993, the first browsers, Viola and Midas, were released for the X-Window system (Unix). At the same time, a Macintosh browser was released as an Alpha – version.

          On February 1993, the first popular graphical World Wide Web browser was NCSA Mosaic. It was released for all common platforms (Unix, Windows and Macintosh) on September 1993.

          When Marc Andreessen, the mastermind of Mosaic founded the Netscape and released a browser (the Netscape Navigator 1.0), he controlled 70% of the browser market. Microsoft saw this huge success and soon released a browser, the MS Internet Explorer, for free.

          Now, the new versions of both the browsers support most of the HTML elements. At present, the more widely used Web browsers for personal computers are the Microsoft Internet Explorer and the Netscape Navigator. Sometimes, while browsing the Web, when a site says “best viewed by Netscape Navigator” or “best viewed by Internet Explorer”, it means that the pages were programmed for that particular browser. 


2012 Second Grading Lecture 2



ELEMENTS OF A WEB SITE

Just like other windows, any web site has a title bar, a menu bar, and a toolbar. The title bar shows the current site being used while the menu bar shows available list command options like file, edit, view, favorites, tools and help. By clicking the Go button, one can go to the web site that appears in the address bar. On the right side of the window, the scroll bar appears where you can scroll up and down on the page.    

The browser window includes an Address Bar that shows the address of your current location. You can always type a new address into the Address field to check out a different Web site.

Lastly, the bottom of the window is a status bar. When you go to a Web page or Web site, the Internet Explorer might take a little time to access the page and display it for you. The status bar shows you where you are in the process while the connectivity icon shows when you are currently connected to Internet or not.

          Like the Word toolbar; however, the Internet Explorer Standard toolbar gives you access to the most commonly used options in the program .

            Back. The Back button returns you to the previous page. You can click it repeatedly to return to a page you have previously visited. The Back button goes back only to sites that you visited during your current session.
          Forward. The Forward button reverses the action of the Back button. If you go back to many pages, the Forward button enables you to move up to where you were. The Forward button goes forward only to sites that you visited during your current session.
          Stop. The Stop button stops a newly selected page from loading. When a page is taking a long time to load, or you see that it is not a page you want, clicking Stop will save you the time it would take to finish loading.
          Refresh. The Refresh button retrieves the page again and reloads it. If you are interested in pages that include information that is constantly being updated—real-time stock quotes, for example—the Refresh button updates the screen with the most current information available.
          Home.  No matter where you find yourself, the Home button brings you back to your home page, that is, the page Internet Explorer first opens to.
Search. The Search button helps you find subject matter when you don’t know where to look.
            Favorites. The Favorites button displays a list of Web sites to which you can go without typing the URL.
          History. The History button shows you all the sites you have visited, listed by date. If you click one of the entries, you jump right to that site.
          Channels. The Channels button offers a diverse selection of Web sites, categorized by topic.
          Full Screen. The Full Screen button enables you to view a maximized Web page without the menu showing.
          Mail. The Mail button helps you manage your e-mail.
          Print. The Print button enables you to print the current Web page.
          Edit. The Edit button enables you to edit the currently displayed page in Notepad.
Find. Although there isn’t a Find button on the Standard toolbar, you can press Ctrl+F to find text on a page.


UNIFORM RESOURCE LOCATOR (URL)

          This is the address that defines the route file on the web. URLs are typed into the browser to access Web pages. The URL contains protocol prefix and domain name. Sometimes, it also includes subdirectory names and file name. For instance,

          This retrieves the home page at Yahoo Web Site. The http:// is the Web Protocol prefix, and www.yahoo.com is the domain name.