There are millions of sites on the web, and a lot of outdated resources, garbage and unfair advertising are adjacent to up-to-date information.
The Internet is the most democratic source of information. Everyone can place their own resource on the Web and express their opinion. This is both a strength and a weakness of the World Wide Web.
Finding information on the Internet would probably be very difficult if powerful search tools were not created: search engines(search engines) rating catalogs(rubricators), thematic lists of links, online encyclopedias and dictionaries.
To search for various kinds of information, various tools turn out to be the most effective.
Resource directories
The directory has a hierarchical structure. Thematic sections of the first level define the broadest possible topics, such as "sport", "leisure", "science", "shopping", etc. Each section can have subsections. The user can specify the area of interest to him, traveling through the directory tree and gradually narrowing the search area. For example, when searching for information about laptops, the search chain might look like this: Information Technology-> Computers -> Laptops. Having reached the desired subdirectory, the user finds a set of links in it.
Usually, all links in the directory are profile links, since it is not programs that are involved in compiling catalogs, but people. It's obvious that if searching general information on some broad topic, it is advisable to refer to the directory. If you need to find a specific document, then the catalog will be an ineffective search tool.
Often, resource directories are also ratings, i.e. The catalog invites the sites registered in it to install on their pages visit counter, and displays lists of links to sites according to their popularity (traffic). The popularity of a resource is evaluated by a number of parameters, including the so-called hosts(amount unique visitors per day) and hits(number of visits to the site per day).
One of the most popular rating catalogs is Rambler's Top 100. (http://top100.rambler.ru/top100/). It is often interesting to assess the state of not all-Russian, but regional resources on a specific topic. To review Krasnoyarsk web resources and the region, you can recommend the catalogs-ratings of resources Krasland (http://www.krasland.ru/) and Stalker (http://www.stalker.internet.ru/).
search engines
Relevant Document- a document whose semantic content corresponds to information request. Modern search engines search by context, i.e. words contained in the query, taking into account the variations of word forms and expanding queries with synonyms. But computers do not understand the meaning, therefore, in the list of responses to a request, along with documents relevant to your request, you can also receive those that do not suit you in any way.
It's obvious that the percentage of received relevant documents depends on the ability to correctly issue a request. The proportion of relevant documents in the list of all found by the search engine is called search accuracy. Irrelevant documents are called noise. If all found documents are relevant (no noise), then the search accuracy is 100%. If all relevant documents are found, then the completeness of the search is 100%.
Thus, the quality of the search is determined by two interdependent parameters: the accuracy and completeness of the search. Increasing the completeness of the search reduces the accuracy, and vice versa.
Search engines can be compared to a help desk, whose agents go around businesses collecting information into a database. When contacting the service, information is issued from this database. The data in the database becomes outdated, so agents update it periodically. In other words, help desk has two functions: 1) creating and constantly updating data in the database and 2) searching for information in the database at the request of the client.
Similarly, a search engine consists of two parts: the so-called search robot(or spider) that traverses the Web servers and builds a database, and search engine links relevant to the user's query in the database.
It should be noted that, when processing a specific user request, the search engine operates with an internal database (and does not start traveling on the Web). Although the database search engine is constantly updated, the search engine cannot index all Web documents: their number is too large. The problem of insufficient search completeness is not only the limited internal resources of the search engine, but also the fact that the speed of the robot is limited, and the number of new Web documents is constantly growing.
The most popular search engines today are Google (www.google.com, www.google.ru) and Yandex (www.yandex.ru).
Online encyclopedias and reference books
In some cases, it may be necessary to find not just a document containing a keyword, but the interpretation of a certain word. When searching for an unfamiliar term using a search engine, you risk getting whole line articles in which this term is used, and at the same time never know what it means after all. Such a search is preferably carried out in an online encyclopedia.
One of the largest online encyclopedias is the Yandex. Encyclopedia resource (http://encycl.yandex.ru/) - this project contains 14 encyclopedias, including articles from the Great Soviet Encyclopedia and the Brockhaus and Efron Encyclopedia. The "Encyclopedia of Cyril and Methodius" (http://www.km.ru) also belongs to the large ones.
In addition to the transfer of traditional dictionaries to the hypertext environment, encyclopedic wiki projects are rapidly developing. Wiki- a website for collecting and structuring written information. It is characterized by the fact that all visitors can fill in and edit the information posted on it. http://ru.wikipedia.org/ - Wikipedia in Russian - part of a multilingual project, the purpose of which is to create complete encyclopedia in all languages of the earth.
Back forward
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Goals:
- understand the basic principles of organizing the search for information on the Internet.
- develop algorithmic thinking, the ability to highlight the main thing, expand the horizons of students by introducing new terms;
- formation of information search skills on the Internet;
- to cultivate a culture of communication: student-student, teacher-student
Tasks:
- Familiarity with the concept of WWW
- Web page, website
- Internet page addressing
- Familiarity with the capabilities of search engines, search queries.
- Use the search and selection of information in practical activities and everyday life
Hardware and software: interactive whiteboard, projector, presentation for the lesson, cards - assignments, a set of assessments.
Lesson type: learning new material.
During the classes
I. Organizational moment.
II. Knowledge update. Presentation of new material.
- Hello guys. Today we will take you on a journey...
Look carefully at the slide. Where do you think we will go?
On a journey through the Internet.
The screen shows an approximate graphic representation of the links between Internet networks. Only links between servers are shown.
What does this picture look like? (To the starry sky, to the web.).
Lesson topic: “WWW. Journey on the World Wide Web”.
But before we cruise around the Web, we will get acquainted with the concept of WWW, Web page, Web site, browser, search engine, and then move on to the practical part: we will work with search engines, make queries, find the necessary information and apply it in practice.
What is the Internet? Internet?t world system of united computer networks for storing and transmitting information. The World Wide Web is based on the Internet
WWW - what does this abbreviation mean? (World Wide Web, WWW)
World Wide Web (WWW, Web) - worldwide NETWORK (web)
WWW is a global repository of information that exists on the technical basis of the INTERNET (after all, there are more than 2 billion Internet users)
WWW - the union of numerous resources distributed around the world;
WWW is an organization of information resources provided with hyperlinks.
WWW - contains information of a very different nature: news, scientific, technical, educational information, advertising of goods and services, resources for leisure and entertainment, communication through social networks, portals and forums and much more. The life of a modern person is now impossible to imagine without the Internet.
Anyone can post information online, and the whole world will have access to this information!
Information on the WWW is organized as Web pages . For example, let's open the website of our school www.schuv1996.mskobr.ru.
website - These are several Web pages that are interconnected by content. In the texts posted on the pages of sites, keywords- hyperlinks.
The address of any file on a worldwide scale is determined unified resource pointer - URL. The URL is a standardized string characters indicating the location of a resource, document or part of it on the Internet, and consists of three parts.
Address structure:
- http:// protocol
- schuv1996.mskobr.ru - server
- news/ - page file
A huge number of hypertext electronic documents stored on WWW servers form a kind of hyperspace of documents between which movement is possible.
But to navigate the user on the "web" help special programs. (Web browsers; browse view, study)
What browsers do you know?
Is there any information storage system on the Internet, is it possible to “get confused” in the web? Is it chaos or is there some kind of system, logic?
In order not to get confused, you need to know where and how to extract necessary information Requires search experience. How to search for information:
- By specifying the address of the document (wikipedia.org)
- By navigating through a web of hyperlinks
- By using search engines. YANDEX, RAMBLER
SEARCH ENGINES (search technology)
All information retrieval systems on the World Wide Web are located on special servers. They serve every day great amount clients. The action of search engines is based on the constant, consistent study of all pages of all sites. For each document, page, there is a certain set of keywords that reflect the content of the page. When a query is received, the search engine generates a list of pages that match the search criteria. Found documents are ordered depending on the location of keywords, the frequency of their occurrence in the text, etc.
What search engines do you know? ( GOOGLE, YANDEX, RAMBLER)
Search engines usually have three operators: "logical AND", "logical OR" and "logical NOT". The "logical AND" operator is indicated between the keywords if it is necessary to return documents containing all the searched words. “Logical OR” is used when it is necessary to search for documents containing at least one of the keywords associated with this operator. The "logical NOT" operator is required to exclude from the list of documents in which there is a word preceded in the query by this operator.
When starting a search, the user enters one or more keywords and selects the search type.
If the search is difficult, try changing the query logic, pick up better synonyms
III. Practical part.
Students are divided into micro-groups.
1 stage of work
You are invited to complete the crossword "History of the INTERNET" ( Attachment 1), using the World Wide Web and search engines known to you.
Everyone is looking for the answer to the first question of the crossword puzzle, but on different search servers.
Let's compare the number of found links to documents and sites for the same query. - Which search engine gave more links?
Whoever found the answer to the question raises his hand and fills in the crossword puzzle on the Smart interactive whiteboard. Students find the right answer and write it down on the interactive whiteboard where the presentation is projected. As a result of the work, all cells of the crossword puzzle are filled.
Notice which keyword is in the highlighted cells? - Internet! Correctly. – So, with the first stage of this task, we coped with it, working together.
Stage 2. Card work
Find answers to the following questions ( Annex 2) and save them in your folders (work in micro-groups):
1) What day is considered the birthday of the Internet in Russia and why?
2) When and where was plombir ice cream invented?
3) Where and when did chocolate appear?
4) What is the brightest star in the night sky?
5) Why is the Black Sea called "Black"?
6) Which country is the smallest? Give it a brief description.
7) When and where were the first Olympic Games held? Give a short description.
Save the information as text and pictures in your folder.
Save information from downloaded Web pages in a variety of ways to your desktop folder:
- how text file , to do this, in the text on the Web page, select the paragraph dedicated to search topic, copy it to the clipboard, start MS Word, execute the "Paste" command, save the resulting document, close MS Word.
- save the drawing from a Web page as a graphic file, to do this, select the picture on the page and click on it with the right mouse button, context menu select the “Save picture as...” item, specify the path, file name and file type (JPG).
- Save a link to a web page
The results of this step should be stored in the folder with your Surname in the My Documents folder.
IV. Grading. Discussion of the results of the work
List the websites you have visited. Please describe these sites. What services do they provide to the user?
At this stage, grades are given based on the results of completing tasks 1 and 2.
V. Reflection.
Today we “walked” around the Internet, got acquainted with the concept of a network - WWW, searched for information on various queries, learned how to correctly receive information from the Internet, got acquainted with such concepts as a browser, URL address, search engines
- What did you like about the lesson? What didn't you like?
- What was new for you in the lesson?
VI. Homework.
Find information on the Internet about the number of users of the most common search engines. When and how did @ originate?
Free access to information, regardless of borders and distances, has become possible thanks to the World Wide Web (WWW, Web) - a global repository of information that exists on the technical basis of the Internet. Perhaps you already have experience with the WWW.
WWW, or World Wide Web:
- is a set of information resources organized into a single whole;
- integrates numerous resources hosted on computers around the world;
- organized in such a way that informational resources are not presented in a linear sequence, but are provided with links (hyperlinks) that clearly indicate possible transitions, links between resources.
The World Wide Web is a powerful information repository; the amount of information contained in it cannot be accurately measured. The WWW contains information of a very different nature; there you can find:
- the latest news - political, economic, cultural, sports;
- scientific, technical, educational and background information absolutely any kind;
- advertising of various goods and services;
- resources for leisure and entertainment - books, music, movies, games and more.
Anyone with access to the Internet can post their information online. The whole world will have access to this information.
Information on the WWW is organized in the form of pages (Web pages). In turn, pages can be combined into larger components - sites (English "site" - a place, a site). A Web site is a set of Web pages linked by content. Government agencies, public organizations, enterprises, firms and companies, museums and libraries, newspapers, educational institutions, including many schools, have websites.
Each site and each page has its own address where they can be accessed. Web sites vary greatly in design, but most often they have a similar structure. Every Web site has a home page, which is similar to the table of contents page in a book. In the texts posted on the pages of sites, keywords can be highlighted - hyperlinks from which hyperlinks go. They are highlighted with color or underlining. By clicking on such a word, we proceed to view another document, and this document may be located on another computer, in another country, on another continent. Not only text can be used as hyperlinks, but also any graphic image. This organization of information is called hypertext.
Special programs help the user navigate the "web" (Web browsers, English "browse", "inspect", "study", Fig. 1.12).
Rice. 1.12.
Logos of the most common browsers - Mozilla Firefox and Internet Explorer
At first glance, the World Wide Web can be thought of as a library in which books are arranged in no apparent order: there is no unified system catalogs, no librarians. At the same time, visitors to the “library” add new volumes at their own discretion or take them away forever. In order to extract useful information from the World Wide Web, you need to know where and how to search, you need experience in search work.
The search for the desired document on the WWW occurs using the browser in different ways:
- by specifying the address of the document;
- by moving along the web of hyperlinks;
- through the use of search engines.
1.6.2. Search engines
All information retrieval systems on the World Wide Web are located on specially dedicated computers with powerful communication channels. Every day they serve a huge number of customers.
The action of search engines is based on the constant, consistent study of all pages of all sites on the World Wide Web. For each document, its search image is compiled - a set of keywords that reflect the content of this document. Due to the constant updating of information, search engines periodically return to previously studied pages to detect and register changes. Information about the keywords of the pages explored in this way is stored in search engine.
When a request is received from the user, the search engine, based on the information available in it, forms a list of pages that match the search criteria. Found documents are usually sorted depending on the location of keywords (in the title, at the beginning of the text), the frequency of their occurrence in the text, and other characteristics.
There are many search engines. In spite of general principle work, search engines differ in query languages, search zones, search depth within a document, information ordering methods, and other characteristics. The most popular search engine in the world is Google. The largest domestic search engines are Yandex, Rambler.
Address: www.google.com
The fastest and largest search engine. Contains information on more than one and a half billion pages. There is a choice of language. Assesses the popularity of a resource by the number of links leading to it from other pages.
Address: www.yandex.ru
Powerful domestic search engine. Provides search, mainly among Russian-language resources, while not inferior to foreign systems in terms of capabilities. Conducts a qualitative analysis of information, taking into account the word forms of the Russian language.
Address: http://www.rambler.ru/
One of the first Russian search engines. In addition to the standard search capabilities, the site has a rating-catalog of resources.
1.6.3. Search terms
When starting a search, the user enters one or more keywords and selects the search type. Most search engines have three main types of searches:
- search by any of the words - the search result is a huge list of all pages containing at least one of the keywords; can be used when the user is not sure about the keywords;
- search by all words - in this search mode, a list of all pages is formed, containing all keywords in any order;
- exact phrase search - as a result of the search, a list of all pages containing a phrase that exactly matches the key phrase is compiled (punctuation marks are ignored).
If too many pages are found, you can add another keyword and repeat the search. To do this, many search engines have a search function among the found. You can also enter search terms using logical connectives similar in meaning to the unions “and”, “or” and the particle “not” of the Russian language (Fig. 1.13).
Rice. 1.13.
Using logical connectives in search queries
The meaning of logical connectives becomes more understandable if they are illustrated using a graphic diagram - Euler circles. Let's imagine the sets of documents that contain the keywords "canaries", "goldfinches" as two circles on the plane, which we will place inside the circle depicting all WWW documents. Then the sets of documents that match our queries (see Figure 1.13) will be represented by the filled areas in Figure 1-13. 1.14.
Rice. 1.14.
Graphical interpretation of logical connectives:
matches: a) the query "canaries & carduelis", b) the query "canaries | carduelis", c) query "~ canaries & carduelis", d) query "~ (canaries | carduelis)"
If as a result of the search you did not find any suitable document, you need to:
- check the spelling of keywords;
- check the correct use of logical connectives;
- choose better synonyms;
- change the logic of the request.
1.6.4. Useful World Wide Web Addresses
The most important
Free access to information, regardless of borders and distances, has become possible thanks to the World Wide Web (WWW, Web, World Wide Web) - a worldwide information repository that exists on the technical basis of the Internet.
To move the user on the "web" help special programs called browsers. The search for the desired document in the WWW can occur: by specifying the address of the document; by moving along the web of hyperlinks; through the use of search engines.
There are many search engines. Most of them have three main types of search: for any of the words; in all words; exactly on the phrase.
Questions and tasks
THE MOST IMPORTANT
Free access to information, regardless of borders and distances, has become possible thanks to the World Wide Weh (WWW, Web, World Wide Web) - a worldwide information repository that exists on the technical basis of the Internet.
To move the user on the "web" help special
programs called browsers. The search for the desired document in WW&V can be performed: by specifying the address of the document; by moving along the web of hyperlinks; through the use of search engines.
There are many search engines. Most of them have three main types of search: for any of the words; in all words; exactly on the phrase.
Questions and tasks
1. Perform a literal translation of the phrase 4 YWorld Wide Web.
2. Describe the organization of the WWW in general terms.
4. Imagine that the text of this paragraph is posted on Web-cafrre. What words from the text can be chosen as key words in order to most accurately convey its meaning? List up to 10 such words.
5. Do you know the address of your school's website? What sites would you recommend visiting your classmates?
b. What browser do you use at school?
7. What search engines do you know?
8. List the main types of search queries.
9. Find information on the World Wide Web about the number of users of the most common search engines.
Present the results of these queries graphically using Euler circles. Specify query designations in ascending order of the number of documents that the search engine will find for each query.
11. Search the World Wide Web for answers to the following questions.
Who is Norbert Wiener and what is his role in the study of information processes?
Who is Claude Shannon and why is he famous?
By whom and when was the term "hypertext" coined?
Who is considered the inventor of WYVW and when did it happen?
Who is Euler, after whom is the graphic diagram illustrating the relationships between sets named?
Test tasks for self-control
1. Which of the following statements most accurately reveals the meaning of the concept of "information" from an everyday point of view?
a) a sequence of characters of some alphabet
b) the book fund of the library
c) information about the surrounding world and the processes taking place in it, perceived by a person directly or with the help of special devices
d) information contained in scientific theories
2. Continuous called signal:
c) carrying text information
d) carrying any information Z. A signal is called discrete:
a) taking a finite number of definite values
b) continuously changing in time
c) which can be decoded
d) carrying some information aci Yu
4. Information that does not depend on personal opinion or judgment is called:
a) understandable
b) up to date
B) objective
d) useful
5. Information material and important in this moment are called:
a) useful
b) up to date
c) reliable
d) objective
b. According to the way of perception by a person, the following types of information are distinguished:
a) textual, numerical, graphical, tabular, etc.
b) scientific, social, political, economic, religious, etc.
c) ordinary, production, technical, managerial
7. It is known that a physically healthy person receives the largest amount of information with the help of:
a) organs of hearing
b) organs of vision
c) organs of touch
d) olfactory organs
e) taste buds
8. Specify the "extra" object in terms of agreement on the meaning of the signs used:
b) road signs
d) musical signs
9. Specify the "extra" object in terms of the type of writing:
a) Russian
in) Chinese
d) French
10. Formal languages include:
a) Russian
b) Latin
c) Chinese
d) French
11. According to the form of presentation, information can be conditionally divided into the following types:
a) mathematical, biological, medical, psychological, etc.
b) sign and figurative
c) everyday, scientific, industrial, managerial
d) visual, auditory, tactile, olfactory, gustatory
12. Discretization of information is:
a) a physical process that changes over time
b) quantitative characteristic of the signal
c) the process of converting information from a continuous form to a discrete one d) the process of converting information from a discrete form to a continuous one
13. Give the most complete answer.
Determine which set of letters is encoded by the binary string 0110100011000.
a) EBCEA b) BDDEA c) CG) CEA d) EBAEA
16. The chessboard consists of 8 columns and 8 rows. What is the minimum number of bits required to encode the coordinates of one chess field?
17. In which line are the units of measurement of information arranged in ascending order?
a) gigabyte, megabyte, kilobyte, byte, bit
b) bit, byte, megabyte, kilobyte, gigabyte
c) byte, bit, kilobyte, megabyte, gigabyte
d) bit, byte, kilobyte, megabyte, gigabyte
18. The size of the message is 11 KB. The message contains 11,264 characters. What is the power of the alphabet with which the message is written?
a) 64 b) 128 c) 256 d) 512
19. Given a text of 600 characters. It is known that the characters are taken from a table of size 16 x 32. Determine the information volume of the text in bits.
A) 1000 b) 2400 c) 3600 d) 5400
20.
The two texts contain the same number of characters. The first text is made up of alphabetic characters with a capacity of 16, and the second text is made up of alphabetic characters with a capacity of 256. How many times more information is there in the second text than in the first?
a) 12 b) 2 c) 24
21. Information processes are:
a) the processes of construction of buildings and structures
b) processes of chemical and mechanical water purification
c) the processes of collecting, storing, processing, searching and transmitting information
d) electricity generation processes
22. Under the information carrier it is customary to mean:
a) communication line
b) the Internet
c) computer
d) a material object on which information can be fixed in one way or another
23. Which line correctly represents the information transfer scheme?
a) source encoder - "decoder -" receiver
b) source - "encoder -" communication channel - "decoder -" receiver
c) source encoder interference - "decoder receiver
d) source decoder communication channel -» encoder receiver
24. Hypertext is:
a) very large text
b) text that can be followed by links
c) text typed on a computer
d) text that uses a large font size
25. A search engine is NOT:
d) Yandex
26. The table shows queries to the search engine. Which query will find the most matching pages for it?
| a) | breeding & keeping & swordtails & catfish |
| b) | content & swordsmen |
| in) | (content & swordsmen) catfish |
| G) | content & swordtails & catfish |
COMPUTER AS A UNIVERSAL DEVICE FOR WORKING WITH INFORMATION