Controlling Idea

An effective topic sentence contains a subject and a treatment. A subject will contain what the intended topic sentence or thesis contains. The treatment contains the intent of the subject or the details. I think that finding the subject and treatment is not always black and white. For instance, "The Internet has changed the way many people shop." is considered to be an effective topic sentence. Some may believe this, but I think that it is a little vague and could be worded better to give a bit more detail. You must use your own judgment because people have individual experiences and views.