Distinguishing The Main Ideas and Supporting Details

One of the skills in reading is to be able to distinguish between the main ideas and the supporting details in a given text.  This starts with the paragraph which is made up of one main idea and the supporting details of that main idea.  Here is an example of how we carry out an activity in order to distinguish between the main idea and the supporting details.  Read the following discussion which is based on the purple paragraph below.

Wary of the high number of crimes committed through social networking websites, many people do take precautions to ensure their safety and privacy. People are taking risks when they put their personal information online. Users should be cautious about what they publish because they never know who might be misusing Facebook.  Information such as birth dates, telephone numbers and revealing photographs can be subject to abuse by rogue users.

1.  What is the paragraph about?

     It is about safety and privacy in social networking sites.


2.  Which sentence best expresses the main idea of the paragraph?
     Wary of the number of crimes committed through social networking websites, many people do take precautions to ensure safety and privacy. 


3.  Why is it called the main idea?
     It is broad enough to summarise all the essential points of the paragraph and specific enough to exclude detailed information.


4.  Where is the main idea found?
     It is found in the first sentence of the paragraph.


5.  What is the function of the other sentences?
     They clarify the main idea.  Although the main idea is expressed in the first sentence, it is not always clearly understood in itself.  So, the other sentences become the supporting details.