Web Searching

Web Search Engine

• A web search engine is designed to search for information on the World Wide Web and FTP servers

• The search results are generally presented in a list of results often referred to as SERPS, or "search engine results pages".

• The information may consist of web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler

Popular Search Engines & Directories

• Ask JeevesAsk Jeeves lets you type a question in plain English and get back easy-to-understand answers. It also has the most integrated search interface of the popular search engines

• GoogleIndex of 10 billion web pages.

• MSNMicrosoft's attempt at a search engine is average.

• Yahoo SearchSecond only to Google.

Basic Search Techniques

Before you search, make a plan!

Basic Search Techniques

1. Identify your conceptsWhen planning your search, break down your topic into its separate concepts. Let's say you're interested in the effects of global warming on crops. In this case, you have two concepts: GLOBAL WARMING and CROPS.

2. Make a list of search terms for each concept

• Once you have identified your concepts, list the terms which describe each concept. Some concepts may have only one term, while others may have many.

global warminggreenhouse effectgreenhouse gasesclimate change

cropscrop yieldscrop productionfood supply

3. Specify the logical relationships among your search terms

• Once you know the words you want to search, you need to establish the logical relationships among them using Boolean logic: AND, OR, NOT.

• To keep things simple, you don't need to use all the words you've compiled in a single search. The words are there to help you experiment with different searches until you find the results you want.

Boolean AND search

• We want Web pages that contain both of our search terms.

Boolean OR search

• If we want results that include either of the word

Boolean NOT search

• Sometimes you want to retrieve documents that do not contain a particular word. This can help when associated words are not really relevant and can muddy the focus of your results. To do this, place a minus sign (-) in front of the word you want to exclude.

Combined Boolean AND, OR search

• When you need a search that is more complex than a single AND or OR search

Phrase Search and Exact Word Search

• simply enclose the phrase within quotes: "freedom of the press".

• whenever you want to search any word exactly as you have typed it, enclose the word within quotes: "president”

Field Search

• Field searching is an optional way to focus your search results. With general search engines, you're searching the full text of many millions of pages, and field searching can help you retrieve results that may be more manageable.

• For example, you can search for words that appear within a particular Web site, within the URL (Web address), in the page title, and so on.

• The exact technique for doing this can differ among search engines, so be sure to check out the Help pages before proceeding. Let's consider a couple of examples on Google.

Title field

• A title search can bring you more relevant results than merely searching for words that appear anywhere on the Web page. It's more likely that a document that contains your search words in the title will be more relevant that a document that does not. For this reason, many search engines use title words as an important way of ranking search results in order of their relevancy.

Site field

• Searching on the site field is another useful way of finding relevant results. In this case, you search on the top-level and second-level domain names together, and then use AND logic to add topical words to your search.

Natural language search

• A few search engines encourage you to type your search as a "normal" question or sentence, rather than concern yourself with Boolean logic. This is sometimes known as a natural language search. On these engines, a variety of sophisticated techniques are working behind the scenes to analyze your search and return relevant results.www.hakia.com

Ask Jeeves