Decide which search engine is the best for each case.

Active vocabulary

Search engine - пошукова система Web crawler - пошуковий робот Database - бази даних Relevant - відповідний probabilistic - імовірнісний expansion - розширення

Query - Запит Entire - Цілковитий Metadata - Метадані To assess - Оцінювати retrieval - знахідка Criteria - критерії

Discussion

Why do people need a search engine? Which search engine do you use? What are your main criteria for choosing a good search engine?

Reading

Read the text below about Search Engines. Choose the best sentence to fill each of the gaps. For each gap 1-5, mark one letter (A-G). There are two extra sentences you don’t have to match. Do not use any letter more than once.

A) The list of items that meet the criteria specified by the query is typically sorted, or ranked.

B) Other types of search engines do not store an index.

C) This is still a developing field, but so far seems to have a lot of potential in making searches more relevant, making the web an even easier place to find exactly what you're looking for.

D) Typically, a search engine works by sending out a spider to fetch as many documents as possible.

E) In the case of text search engines, the search query is typically expressed as a set of words that identify the desired concept that one or more documents may contain.

F) Each search engine uses a proprietary algorithm to create its indices such that, ideally, only meaningful results are returned for each query.

G) Search engines help to minimize the time required to find information and the amount of information which must be consulted, similar to other techniques for managing information overload.

A search engine is an information retrieval system designed to help find information stored on a computer system. 1) …….. The most public, visible form of a search engine is a Web search engine which searches for information on the World Wide Web.

Search engines provide an interface to a group of items that enables users to specify criteria about an item of interest and have the engine find the matching items. The criteria are referred to as a search query. 2) ……. There are several styles of search query syntax that vary in strictness. It can also switch names within the search engines from previous sites. Whereas some text search engines require users to enter two or three words separated by white space, other search engines may enable users to specify entire documents, pictures, sounds, and various forms of natural language. Some search engines apply improvements to search queries to increase the likelihood of providing a quality set of items through a process known as query expansion.

3) …… Ranking items by relevance (from highest to lowest) reduces the time required to find the desired information. Probabilisticsearch engines rank items based on measures of similarity (between each item and the query, typically on a scale of 1 to 0, 1 being most similar) and sometimes popularity or authority or use relevance feedback. Boolean search engines typically only return items which match exactly without regard to order, although the term Boolean search engine may simply refer to the use of Boolean-style syntax (the use of operators AND, OR, NOT, and XOR) in a probabilistic context.

To provide a set of matching items that are sorted according to some criteria quickly, a search engine will typically collect metadata about the group of items under consideration beforehand through a process referred to as indexing. The index typically requires a smaller amount of computer storage, which is why some search engines only store the indexed information and not the full content of each item, and instead provide a method of navigating to the items in the search engine storage page. Alternatively, the search engine may store a copy of each item in a cache so that users can see the state of the item at the time it was indexed or for archive purposes or to make repetitive processes work more efficiently and quickly.

4) ……. Crawler or spider type search engines may collect and assess items at the time of the search query, dynamically considering additional items based on the contents of a starting item (known as a seed, or seed URL in the case of an Internet crawler). Meta search engines store neither an index nor a cache and instead simply reuse the index or results of one or more other search engines to provide an aggregated, final set of results.

The newest trend in search engines, and likely the future of search in general, is to move away from keyword-based searches to concept-based searches. In this new form of search, rather than limiting a search to the keywords the searcher inputs, the search engine tries to figure out what those keywords mean, so that it can suggest pages that may not include the exact word, but nonetheless are topical to the search. 5) …….

Language practice

Use the text above to write in the third column an appropriate synonym for the words given in the second one. Then complete the sentences with the most suitable words.

1. Search engines _________ filter out duplicated content. 2. Slow internet is the most annoying thing in the _________ world. 3. Most Web browsers include functionality to let you decrease the text in a Web page. 4. The primary _________of metadata is to improve resource recovery. 5.An Internet _________is someone who has become famous by means of the Internet. 6.A virus might _________ infect every application file on an individual computer. 7. _________ studies show that cache memories are among the most vulnerable components. 8.The benefit of this system over the Search Engine is that the user is directed to the expert's answer to the_________. 9.It is _________ that the internet is going to expand in the coming years. 10.Google does not _________ the use of products that send automatic or programmatic queries to Google.	RECOMMEND CELEBRITY DECREASE ACTIVELY QUESTION RAPIDLY EVIDENT RECENT WHOLE AIM	_____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________

Using information from the text, complete these statements.

1. A search engine is used for _____________________________________________________

2. An interface makes possible ____________________________________________________

3. Some search engines apply improvements for ______________________________________

4. Measures of similarity is the main feature used for __________________________________

5. Boolean search engine is characterized by _________________________________________

6. A search engine collects metadata for _____________________________________________

7. Cache can be used for _________________________________________________________

8. The difference betweenCrawler search engines and Meta search engines is_______________

_____________________________________________________________________________

Match the statements on the left with the suitable definitions on the right.

Statements	Definitions
Search engine	It describes how and when and by whom a particular set of data was collected, and how the data is formatted.
Crawler/ spider	The process of reformulating a seed query to improve retrieval performance in information retrieval operations.
Search query	A program that runs automatically without human intervention.
World Wide Web	A question processed by a search engine which returns a list of web pages that closely match the query.
Metadata	The ability of a computer program to understand human speech as it is spoken. It is a component of artificial intelligence (AI).
Query expansion	A component that transparently stores data so that future requests for that data can be served faster.
Natural language	A program that searches documents for specified keywords and returns a list of the documents where the keywords were found.
Cache	A system of interlinked hypertext documents accessed via the Internet.

Read the text and then write the correct form of the word in CAPITALS to complete the gaps. The first is done.

There are three common Boolean operators: AND, OR, NOT. OR is used to join synonymous or 1)related terms, and instructs the search tool to retrieve any record that 2)……….. either (or both) of the terms, thus 3) ……….. your search results. The OR operator is particularly useful when you are unsure of the words used to categorize your topic or if 4)……….. on your topic is even available. AND is used to join words or phrases when both (or all) the terms must appear in the items you 5) ………... This search query would return a much smaller set of records, and the items found would be more specific to your research question. NOT is used to exclude a particular word or 6)……….. of words from your search results. If you are retrieving many records that are unrelated to your topic, try 7)……….. the NOT operator to eliminate a word. It is also possible to perform complex Boolean searches in which more than one Boolean Operator is used. To do this, enclose the terms 8) ……….. with OR within parentheses.

1) TO RELATE 2) TO CONTAIN 3) TO BROADEN 4) TO INFORM 5) TO RETRIEVE 6) TO COMBINE 7) TO USE 8) TO CONNECT

To simplify your search make a search decision.

If...	Then...
Your topic is broad.	Go to a directory to browse subject categories. You may find subjects that will lead you to the name you want.
You know what you want but can’t think of the name for it.	Go to a directory site. Choose a subject category that matches your topic. Then narrow your topic by browsing the sub-categories.
You need to come up with a topic.	Enter your keywords in quotation marks to make sure you get the whole name and not just one part of it.
Your topic is narrow.	Browse the subject categories in a directory, selecting subcategories until you find a topic that seems just right.
Your topic is narrow and a proper noun.	Enter only the root of the word followed by an asterisk. The asterisk acts like a “wild card” telling the search engine to find any words with that root.
Your topic is narrow and an exact phrase.	Enter your phrase in quotation marks to make sure you get the whole phrase.
You want to search for all the keywords related to a single root.	Go to a search service known for its huge index of sites or a meta-search engine that will submit your search to many search engines at once. Enter your keywords into the search tool.

Decide which search engine is the best for each case.

Дата добавления: 2015-10-29