Some variables best stay hidden; however for other options, you can let your form users be much more flexible.

You want to let your users search for PowerPoint files, but you also want them to be able to search for Excel files and Microsoft Word files. In addition, you want them to be able to search tompeters.com, the State of California, or the Library of Congress. There are obviously various ways to do this user-interface-wise; this example uses a couple of simple pull-down menus:

Find net cams with the following searches:

inurl:"ViewerFrame?Mode="
intitle:"WJ-NT104 Main Page"
inurl:netw_tcp.shtml
intitle:"supervisioncam protocol"

Search engines are not all the same. Of course, each search engine uses some method to find its results. The search method that a search engine uses determines the quality and quantity of results that a user will get for any particular search. Generally, search engines can be categorized as author-controlled (keyword relevancy), editor-controlled (directories), user-controlled, or pecuniary- controlled. Each of these different methods that search engines use to find the user’s topic of interest skews the relevancy ranking differently.

Author-controlled search engines such as Google and AltaVista operate on keywords that the user supplies to the search engine interface. The search engine then searches its cache of web documents for matches to the keywords, returning those web page links in some predefined order as the search results.

Keywords, also called query words and search words, are those words describing the subject of interest. For example, a person searching for information on a Florida vacation might enter the words “Florida” and “hotel.” Of course, the search engine cannot distinguish between the hotels in Miami and Orlando, so the results will include all web pages containing those two words without regard to any specific Florida city. To narrow the search focus to the city of interest (say, Orlando), the searcher must include “Orlando” as another keyword in addition to “Florida” and “hotel.” So, the more specific the keywords utilized, the fewer but more targeted search results the user will receive. Then he or she is on the path to search nirvana.

An important consideration of author-controlled search engines is the methods used to determine the relevancy of web pages to the search criteria or the keywords. Author-controlled searching relevancy ranking will depend upon the search algorithm that the search engine uses. Some may skew the results based upon size of company, link popularity, quality of web page, and/or whether the page is commercial (.com), government (.gov), or educational (.edu).

Editor-controlled search engines, such as Yahoo in its original form and LookSmart, place web page links into structured directories based upon subject matter. This type of search engine may be totally software driven or may involve some human intervention. The user may travel the top-down directory structure until arriving at the topic of interest, or he or she may search the directory for the topic of interest. The web pages are usually placed in alphabetical order within the directories.

User-controlled search engines depend upon not link popularity but rather visitor popularity. That is, the more visitors a web page receives, the higher it will rank in a search result. An example of a user-controlled search engine is Direct Hit. Direct Hit rankings are dependent upon the number of visitors to each site. The greater the number of visitors, the greater the relevancy ranking. Relevancy ranking in this case seems to be democratic in a way. However, behind every search engine is a group of individuals who can manipulate the results as they deem appropriate. Additionally, an enterprising web site operator can easily design a software program that can automatically visit the site repeatedly, garnering a top position in a very short period of time.

Pecuniary-controlled relevancy ranking is simply paid placement. It is also controversial, as it ensures a certain spot in the search results. Of course, the highest spot in the search results costs the most money. It’s not very democratic, as one usually will not find a small, enterprising company trying to establish a market on the Internet using this method of gaining web traffic to its site.

Relevancy ranking is an important concept for search engine technology. Relevancy ranking means how relevant a web site is to the search words entered by the user. When we search for web sites, we enter certain keywords in the search engine’s search box. We expect the search engine to return the URLs of web sites that contain relevant information. If we search on “flowers,” we do not care to discover that the search engine returns web sites whose content is “furniture.” So, when the search engine’s database is searched, an algorithm that ranks each site containing one or more of the keywords is employed. What are the mechanics of the ranking algorithms? Well, knowing that is a substantial part of the cat and mouse game that search engine owners and web site developers have played since about 1993. Suffice it to say that useful and relevant web site content is very important.

However, by utilizing a search engine’s advanced search capabilities, a user can easily narrow the engine’s focus to the most relevant sites.

info: 

An info: query returns links to the domain name included in the query along with the first 24 or so words in the web page’s title or upper page information. The format for an info: query is the same as a related: query, [info:www.yahoo.com]. Just like a related: query, you can place keywords after the domain name in an info: query, and the Google search engine will exclude any links of web pages that do not include those keywords. Try an info: query on big corporations like Ford, GM, Lockheed, and your company.

Things to remember about an info: query:

1.  An info: query works in any Google query/search box.
2. You can use up to ten keywords in an info: query if you place them after the domain name, separated by spaces.

allintitle:

The allintitle: query will restrict search results to links to those web pages containing all of the keywords in the title of the page. The form of the allintitle: query is allintitle:keyword xxx], where xxx is one or more keywords, up to a maximum of ten. All of the keywords appear in the title since the operator is “all in the title.” For example, to search for resumes of engineers other than civil engineers, our query would look like [allintitle:resume engineer -civil -post]. We exclude civil (-civil) in the query since we are not interested in civil engineers, at least in this example. Also, we want to exclude those commercial sites seeking resumes to post, so we use “-post”. You can include up to ten words in the query. All words in the query must appear in the title for links to those pages to appear in the search results

If you are seeking employees, isn’t this a wonderful way to find prospective candidates? Things to remember about an allintitle: query:

1. An allintitle: query works in any Google query/search box.
2. You can include up to ten keywords in an allintitle: query.
3. The allintitle: query functionality is also present in the Advanced Search page.

The simplest and most identifiable method of partnering with Google is to incorporate Google searching on your site. You may offer Google search to your visitors free of charge (to them and to you), and you may customize the search to a reasonable degree. Giving your users options to search the Web or your site (or other specific sites) is fairly easy.

Google offers four free search services and three paid services:

Free Services 

1. Google Free: A Google-branded search box that delivers Web results.
2. Google Free: Safe Search. Same as Google Free, but delivers edited search results free of adult content.
3. Google Free Web and Site Search: An enhanced version of Google Free with an added option to search only your site or only another site selected by you.

 Paid Services

1. Customized Free Web (and Site) Search. With or without the Site Search option, free customization is available to registered users, enabling them to display search results under their site’s logo and with their site’s colors. 
2. Silver and Gold Search: Two paid search service plans for sites conducting millions of searches per year. 
3. Custom Web Search: The highest level of paid search, for extremely high traffic sites. ISPs and publishers such as EarthLink and the Washington Post are two clients of Custom Web Search.