Y . UIR practical 4 & 5 . Thursday, November 29, 2007 .
In this pratical, I'm suppose to use the three different types of search facilities (search engine, meta-search engine, subject directory search engine) to research on a topic. The topic that I've chosen is 'Discuss the impact of drug abuse on youths'.
Search engine used: google
Keywords used: Drug abuse on youths
URL of resource: http://www.nationalyouth.com/substanceabuse.html
Google return me with 1,920,000 results but only the first 20% of the results provides information about the effects of drug abuse. The URL that I wanted appears in the top 5 of the search results.
Meta-search engine used: mamma
Keywords used: effects +(drugs abuse) + teenagers
URL of resource: http://helpguide.org/mental/drug_substance_abuse_addiction_signs_effects_treatment.htm
Mamma return me with 53 results and more than 60% of the results give information about effects of drug abuse. The URL that I wanted appears in top 20 of the search results.
Subject-directory search engine used: galaxy
Links: Community/Health/Teen health/Teen substance abuse
URL of resource: http://www.focusas.com/SubstanceAbuse.html
Galaxy return me with 27 results and only 3 results provide information about the effects of drug abuse on youths. The URL that I wanted appears in top 10 of the search results.
Compare the search results. Identify 2 characteristics that make all 3 search facilities similar or different from one another.
I have found out two characteristic that makes the different type of search engines dfferent.
Firstly, the way of searching using different type of search engines is different.
A search engine will search for its database for the keywords typed. It will display the results in order in which they think is the most relevant as the first result. Owners of website can also pay search engines to place their website as one the top results search.
Meta-search engines, also known as metacrawlers or multi-search engines, do not have their own database and will send the keywords typed to the different search engines available and display the results from the different websites in the order where the most relevant website will be placed as the first few results. The advantage of this type of search engine is that it will be able to display more variety of results compare to normal search engine and they group similar subjects in a group.
Subject-based search engines, also known as subject catalogs, allows user to search stuffs by different categories. The list is arranged in a hierarchy way and by doing do, its more organized when comes to searching. The results are often very specific too. However, the results are computed by human therefore limited, giving the user a limited choice of results to choose from.
Secondly, the way the results display of the different type of search engines is also different. The largest amount of results given will be search engines, meta-search engines being the second most and lastly few results are displayed for the subject directory search engine. Subject directory is the least as the results are manually computed and therefore, limited resources available.
Do you find any strength/weakness of each of them, in terms of search capability?
Strength of search engine:
It visits a web page and read it, takes note of the content (first 100 keywords, entire full text or top level of a site) and goes back on regular basis to look for changes. It contains an index that has a copy of every web page it finds and is always updated with the changes it finds in the webpage. It always provides user with a wide range of results but careful usage of keywords with relevant Boolean operators is needed to get relevant results shown in the top few results instead of showing a chunk results where most of them are not useful.
Weakness of search engine:
Provides whole chunk of results that searcher have to spend lots of time reading through them to get the most useful result for him.
Strength of meta-search engine:
Lesser results are displayed as the results are grouped according to the subject and this saves times in going through lots of results given by normal search engine. It also displays which search engines it got the website from which is also useful for the searcher if he only wishes to visit sites that are found from certain search engines.
Weakness of meta-search engine:
I personally feel that there is no weakness for meta-search engines.
Strength of subject directory engine:
This search engine narrows the results through specific directories, therefore always displaying only a few results which means lesser time spend on reading unwanted results. Directories are also clearly defined so that users only need to click on the links to get the results they want.
Weakness of subject directory engine:
The results are often too little and there may not be even one link which is useful to the searcher. The searcher also can’t do any comparison between different results to see which results are more useful for the searcher.
Overall, which search facility best meet your searching needs? Why?
Meta-search engine would meet best for my searching needs as it searches for the keywords keyed in and transmit the keywords simultaneously to several search engines and display the results. Therefore, instead of getting results from only one search engines, I’m able to get results from more than one search engine and therefore, giving me more variety of results to get from. Even though for my topic in this case, I got the result I want in the top 20 results, I still find that the grouping of similar subject links together is very useful and is able to get links from different search engines.
From this practical, I've learnt how the different type of search engine works and is able to use the different type of search engines in a more effiecient way in the future to get whatever resources I need from the internet.