To find the information you are interested in, you need to indicate to the browser the address of the Web page on which it is located. This is the fastest and most reliable type of search. For quick access to the resource, it is enough to launch a browser and type the page address in the address bar.

The addresses of Web pages are given in special reference books, printed publications, and are heard on the air of popular radio stations and from TV screens.

If you do not know the address, then to find information on the Internet there are search engines, which contain information about Internet resources.

Each search engine has a large database of keywords associated with the Web pages on which they appear. To search for the server address with the information you are interested in, you must enter a keyword, a few words or a phrase in the search engine field. By doing so, you send search engine inquiry. Search results are returned as a list of Web page addresses that contain these words.

Typically, search engines consist of three parts: a robot, an index, and a query processing program.

A robot (Spider, Robot or Bot) is a program that visits web pages and reads (in whole or in part) their content.

Search engine robots differ in the individual scheme for analyzing the content of a web page.

Index is a data warehouse that contains copies of all pages visited by robots.

Indexes in each search engine differ in the volume and method of organizing the stored information. Databases of the leading search engines store information on tens of millions of documents, and their index is hundreds of gigabytes. Indexes are periodically updated and supplemented, so the results of the work of one search engine with the same query may differ if the search was made at different times.

A query processor is a program that, in response to a user request, "scans" the index for the information it needs and returns links to the documents it finds.

A set of links at the output of the system is distributed by the program in descending order from the highest degree of matching the link to the request to the smallest one.

In Russia, the most common search engines are:

Rambler (www.rambler.ru);

Yandex (www.yandex.ru);

Mail (www.mail.ru).

There are many more search engines abroad. The most popular are:

Alta Vista (www.altavista.com);

Fast Search (www.alltheweb.com);

Google(www.google.com).

Yandex is perhaps the best search engine in Russian Internet... This database contains about 200,000 servers and up to 30 million documents, which the system views within a few seconds. Using this system as an example, we will show how the search for information is carried out.

Search for information is set by entering a keyword into a special frame and clicking the "Find" button to the right of the frame.

Search results appear within seconds, and are ranked by importance - the most important documents are placed at the top of the list. In this case, the rank of the found document is determined by where the keyword is located in the document (it is more important in the title of the document than in any other place) and the number of mentions of the keyword (the more mentions, the higher the rank).

Thus, the sites located in the first places in the list are leading not from a content point of view, but practically, in relation to the frequency of the keyword. In this regard, one should not be limited to viewing the first ten sites suggested by the search engine.

The content of the site can be indirectly assessed by its short description posted by the Search engine under the address of the Site. Some unscrupulous authors of sites, in order to increase the likelihood of their Web page appearing in the first places of the Search engine, deliberately include in the document meaningless repetitions of the keyword. But as soon as the search engine finds such a "littered" document, it automatically excludes it from its database.

Even a ranked list of documents offered by a search engine in response to a key phrase or word can be nearly overwhelming. In this regard, Yandex (like other powerful Search Engines) provides an opportunity, within the first list, to select documents that more accurately reflect the purpose of the search, that is, to clarify or improve the search results. For example, a keyword is a list of 34,899 Web pages. Entering a lookup keyword into the Look in Found command shrinks the list to 750 pages, and typing another lookup word into the command shrinks the list to 130 Web pages.

They say that the Internet has it all. In fact, it is not so. Materials for posting on the network are prepared by real people, and therefore you can find there only what they saw fit to publish. However, the river is fed by streams, and, thanks to their work, today there are about two billion Web pages on the Internet. As a result, cataloging the resources available on the web has become a serious problem. Despite the fact that thousands of organizations are dealing with the problem, it is not only not getting closer to resolution, but is becoming more acute. The percentage of cataloged resources has been steadily declining. In recent years, this decline has become catastrophic. So, if in 1999 the percentage of cataloged resources approached 40%, then in just one next year it dropped to 25%.

The takeaway is simple: the Web space fills up faster than it gets organized.

Unfortunately, we have no reason to believe that anything can change for the better in the near future. As a result, finding information on the Internet can be considered one of the most difficult tasks.

To find the information you are interested in, you need to indicate to the browser the address of the Web page on which it is located. This is the fastest and most reliable type of search. For quick access to the resource, just launch a browser and type the page address in the address bar.

The addresses of Web pages are given in special reference books, printed publications, and are heard on the air of popular radio stations and from TV screens.

If you do not know the address, then to find information on the Internet there are search engines, which contain information about Internet resources.

Each search engine has a large database of keywords associated with the Web pages on which they appear. To search for the server address with the information you are interested in, you must enter a keyword, a few words or a phrase in the search engine field. Thus, you send a request to the search engine. Search results are returned as a list of Web page addresses that contain these words.

Typically, search engines have three parts: robot, index and request processing program.

A robot (Spider, Robot or Bot) is a program that visits web pages and reads (in whole or in part) their content.

Search engine robots differ in the individual scheme for analyzing the content of a web page.

Index is a data warehouse that contains copies of all pages visited by robots.

Indexes in each search engine differ in the volume and method of organizing the stored information. Databases of the leading search engines store information on tens of millions of documents, and their index is hundreds of gigabytes. Indexes are periodically updated and supplemented, so the results of the work of one search engine with the same query may differ if the search was made at different times.

A query processor is a program that, in response to a user request, "scans" the index for the information it needs and returns links to the documents it finds.

A set of links at the output of the system is distributed by the program in descending order from the highest degree of matching the link to the request to the smallest one.

In Russia, the most common search engines are:

• Rambler (www.rambler.ru);
• Yandex (www.yandex.ru);
• Mail (www.mail.ru).

There are many more search engines abroad. The most popular are:

• Alta Vista (www.altavista.com);
• Fast Search (www.alltheweb.com);
• Northern Light (www.northernlight.com).

Yandex is perhaps the best search engine on the Russian Internet. This database contains about 200,000 servers and up to 30 million documents, which the system views within a few seconds. Using this system as an example, we will show how the search for information is carried out.

Search for information is set by entering a keyword into a special frame and clicking the "Find" button to the right of the frame.

Search results appear within seconds, and are ranked by importance - the most important documents are placed at the top of the list. In this case, the rank of the found document is determined by where the keyword is located in the document (it is more important in the title of the document than in any other place) and the number of mentions of the keyword (the more mentions, the higher the rank).

Thus, the sites located in the first places in the list are leading not from a content point of view, but practically, in relation to the frequency of the keyword. In this regard, one should not be limited to viewing the first ten sites suggested by the search engine.

The content of the site can be indirectly assessed by its short description posted by the Search engine under the address of the Site. Some unscrupulous authors of sites, in order to increase the likelihood of their Web page appearing in the first places of the Search engine, deliberately include in the document meaningless repetitions of the keyword. But as soon as the search engine finds such a "littered" document, it automatically excludes it from its database.

Even a ranked list of documents offered by a search engine in response to a key phrase or word can be nearly overwhelming. In this regard, Yandex (like other powerful Search Engines) provides an opportunity, within the first list, to select documents that more accurately reflect the purpose of the search, that is, to clarify or improve the search results. For example, a keyword is a list of 34,899 Web pages. Entering a lookup keyword into the Look in Found command shrinks the list to 750 pages, and typing another lookup word into the command shrinks the list to 130 Web pages.

Search directories are a systematic collection (selection) of links to other Internet resources. Links are organized as thematic rubricator, npe, which is a hierarchical structure, moving through which you can find the information you need.

Let's take as an example the structure of the Yandex.

This is a general purpose directory, as it contains links to Internet resources in almost all possible directions. The following are highlighted in this directory themes:

• Business and Economics;
• Society and Politics;
• Science and education;
• Computers and communications;
• References and links;
• Home and family;
• Entertainment and recreation;
• Culture and art.

Each theme includes many subsections , and they, in turn, contain rubrics etc.

Suppose you are preparing an event for the Victory Day and want to find the words of the famous military song by Bulat Okudzhava “You hear the boots rumbling” on the Internet. The search can be organized as follows:

Yandex> Catalog> Culture and art> Music> Author's song

This search method is quite fast and efficient. At the end, you are offered just a few links, among which there are links to sites with songs of famous bards. It remains only to find an archive with the lyrics of B. Okudzhava's songs on the website and select the desired text in it.

Another example. Suppose you are going to buy a mobile phone and want to compare the characteristics of devices from different companies. The search could be carried out on the following headings of the catalog :.

Yandex> Catalog> Computers and communications> mobile connection> Mobile phones

Having received a limited number of links, you can quickly view them and select a phone by examining the characteristics of the firms and modifications of the devices.

Most search engines have the ability to search for keywords. This is one of the most common types of searches.

To search for keywords, you need to enter a word or several words that you want to search in a special window and click on the Find button.

The search engine will find in its database and show documents containing these words. There may be many such documents, but many in this case does not necessarily mean good.

Let's do some experiments with any of the search engines. Suppose that we decided to start an aquarium and we are interested in any information on this topic. At first glance, the simplest thing is to search for the word "aquarium". Let's check this, for example, in the Yandex search engine. The search result will be great amount pages - a huge number of links. Moreover, if you look more closely, among them there will be sites mentioning B. Grebenshchikov's group "Aquarium", shopping centers and informal associations with the same name, and much more that has nothing to do with aquarium fish.

It is easy to guess that such a search cannot satisfy even an unassuming user. Too much time will have to be spent trying to select among all the proposed documents those that relate to the subject we need, and even more so to familiarize ourselves with their contents.

You can immediately conclude that it is usually impractical to search for one word, because it is very difficult to determine the topic of a document, web page or site from one word. The exception is rare words and terms that are almost never used outside their subject area.

Having a certain set of the most common terms in desired area, you can use advanced search. In fig. shows the advanced search window in the Yandex search engine. In this mode, the capabilities of the query language are implemented as a form. Similar service, which includes dictionary filters, is offered by almost all search engines.

Let's try to clarify the search terms and enter the phrase "aquarium fish". The number of links will decrease by more than 20 times. This result suits us more, but all the same, among the proposed links we may find, for example, Russian souvenir sets of matchsticks with images of fish, and collections of screensavers for the Desktop of a computer, and catalogs of aquarium fish with photos, and stores of aquarium accessories. Obviously, we should continue to move towards clarifying the search conditions.

In order to make the search more productive, all search engines have a special query language with its own syntax. These languages ​​are similar in many ways. All of them are difficult to learn, but any search engine has a help system that will allow you to master the language you want.

Here are some simple rules for generating a query in the Yandex search engine.

The keywords in the query should be written in lowercase (small) letters.

This will ensure that all keywords are searched, not just those that start with an uppercase letter.

The search takes into account all forms of a word according to the rules of the Russian language, regardless of the form of the word in the query.

For example, if the word “know” was specified in the query, then the words “know”, “know”, etc. will also satisfy the search term.

To search for a stable phrase, you must enclose the words in quotation marks.

For example, "china tableware".

To search for an exact word form, an exclamation mark must be placed in front of the word.

For example, to search for the word "September" in the genitive case, write "! September".

To search within one sentence, the words in the query are separated by a space or by &

For example, "adventure romance" or "adventure & romance". Several words typed in the query, separated by spaces, mean that they must all be included in one sentence of the required document.

If you want to select only those documents that contain each word specified in the request, put a plus sign "+" in front of each of them. If, on the contrary, you want to exclude any words from the search result, put a minus "-" in front of this word. The signs "+" and "-" must be written through a space from the previous one and merged with the next word.

For example, the query “Volga-car” will find documents that contain the word “Volga” and no word “car”.

When searching for synonyms or words that are close in meaning, you can put a vertical bar "|" between words.

For example, by request “child | baby | baby ”documents with any of these words will be found.

Instead of one word in the query, you can substitute an entire expression. To do this, it must be enclosed in brackets.

For example, "(child | toddler | children | infant) + (care | upbringing)".

The "~" (tilde) character allows you to find documents with a sentence containing the first word but not the second.

If the operator is repeated once (for example, & or ~), the search is performed within the clause. The double operator (&&, ~~) searches within the document.

For example, the query "cancer ~~ astrology" will find documents with the word "cancer" that are not related to astrology.

Let's go back to the aquarium fish example. After reading several documents offered by the search engine, it becomes clear that the search for information on the Internet should not start with the selection of aquarium fish. An aquarium is a complex biological system, the creation and maintenance of which requires special knowledge, time and serious investment.

Based on the information received, a person performing a search on the Internet can radically change the strategy for further search by deciding to study the special literature related to the issue under study.

To search for literature or full-text documents, the following query is possible:

"+ (Aquarium | aquarist | aquarium hobbyist) + for beginners + (advice | literature) + (article | thesis | full-text) - (price | shop | shipping | catalog)".

After processing the request by the search engine, the result was very successful. Already the first links lead to the documents you are looking for.

Now you can summarize the search results, draw certain conclusions and decide on possible actions:

• Stop further search, as for various reasons you cannot afford to maintain an aquarium.
• Read the suggested articles and start setting up your aquarium.
• Look for material about hamsters or budgerigars.

1. What kind of search is the fastest and most reliable?
2. Where can a user find the URLs of Web pages?
3. What is the main purpose of a search engine?
4. What are the parts of a search engine?
5. What search engines do you know?
6. What is the search technology for a search engine rubricator?
7. What is the keyword search technology?
8. When should a + or - be specified in the search criteria?
9. What search criteria in Yandex are specified by the following phrase:

   (nanny | educator | governess) ++ (care | upbringing | supervision) ?

10. What does double sign (~~ or ++) mean when generating a complex query?

Exercise.