Search engines allow people to search the Web for information by entering keywords into a query box. A list of results is then returned, ranking the pages based on their relevance to the query. The algorithms that determine how a page is ranked differ between search engines, and the technology changes over time. By understanding how these techniques work, you can improve your chances of getting the answers you are looking for from a search engine.
A search engine can return millions of results, but the usefulness of those results depends on how relevant they are to your query. Search engines use algorithms that analyze the content of a Web page, read its meta tags and follow links to other pages. They also consider the number and location of words in a page’s content, the frequency of those words, and the context of their appearance in relation to other words in a page. By comparing the keywords you entered to those used on other pages, the algorithm is able to judge how well a page matches your request and how important it is in its field of reference.
While a standard Web search engine may be adequate for most purposes, you can greatly increase the utility of it by constructing your search string with various search techniques. Adding phrases, wildcards and Boolean logic can dramatically reduce the number of records your search returns while ensuring that you get all of the information that is important to you.
Searching for information online can be a difficult task, and even the most basic of searches often generates too many or not enough results. By putting a little thought into how you phrase your search queries, you can narrow the scope of the information you receive, and save a lot of time.
The simplest technique is to place keywords in quotes around them. This tells the search engine that you are searching for exact words and phrases, which should drastically reduce the amount of irrelevant information it returns.
You can also use asterisks (*) to search for words or phrases that might appear anywhere on a Web page. The search engine will scan all of the pages in its index for these terms and return the most relevant ones. This can be a very helpful tool for finding specific types of documents, but it is not recommended for general searches because it can produce too many unrelated results.
There are also specialty search engines designed to help you find particular kinds of media files, jobs or other items. These include audio, image, invisible Web, job and torrent search engines. You can learn more about these and other search engines in the module Search techniques – from snowball to cited reference search (5:54). You can also watch the video Searching databases (4:54) for a more detailed explanation of database search methods. Both are available from the Learning Centre. Both videos are free to view and can be accessed by logging into the Library and then selecting the appropriate topic from the menu on the left hand side of this screen.