Practical 4 & 5

The purpose of this practicals is to assist us in doing our very first assignment. Basically, what I have to do is to compare 3 different types of search facilities using the Topic: Drug abuses on Youths selected previously.
The 3 types of facilities are: Search Engines, Meta Search engines, and Subject Directories.

For search engines, I chose the most famous - www.google.com

Google ranks results by the number of links from the largest number of pages also ranked high by the service. The more highly ranked pages that link to a certain page, the higher the linked-to page will be ranked by Google. This unique ranking system can be quite effective. It is also possible to search Images, Groups and News from the tabs available.

For Meta Search Engines, I chose www.metacrawler.com
Meta search engines simultaneously search multiple search engines and returns results from each sources minus the duplicate files. Therefore only a limited number of results available will be returned from each source when you do a search.

I chose dir.yahoo.com for my subject directories because it was the only one I knew of.
The way of searching for yahoo directory is to click on the topic that you are looking for and it will break down into a smaller scope for you to find your information.

To conclude,

Google, as a search engine, is good for looking for a specific topic and if your topic is made up of multiple ideas. This can be attributed to the usage of the advanced search interface that allows you to do a search that is targeted at your needs. The link ranking of results may also bring extremely relevant results to the top. However, due to the large number of hits, browsing every links may be not very efficient.

Metacrawler, the meta search engine, is good for searching multiple sources at the same time. This may come in handy if the topic you are searching on is obscure and made up of multiple concepts. The number of hits is slightly more than Directory but this may mean some relevant websites are omitted. It should be noted that even though metacrawler may obtain some same results as google, it is not necessary a better way to do an internet search as it does not represent the totality of result. Its use is also limited to simple queries.
Yahoo Directory, the subject directory, is an excellent place to start research on a topic that is broad. Being able to browse through subject categories is extremely useful and even searching the directory results in a small amount of hits that is efficient for browsing link by links on the relevant resources. Because the results are human compiled, the results have already been selected carefully by various people and therefore may return the most relevant results of all the search facilities.