how should I use "as opposed to"
My dictionary tells me : "as opposed to" = "rather than"
Are they exchangeable in the following sentences?
1. Students discuss ideas, as opposed to just copying from books.
2. The media seems interested in his private life as opposed to his public life.
3. I think I'd like to stay at home this evening rather than go out.
but I am also confused about this sentence.
4. People have different views about the effectiveness of group study as opposed to working alone.
can "as opposed to" be replaced by "rather than", or "compared to" ?

Thank you very much.

Question

how should I use "as opposed to"
My dictionary tells me : "as opposed to" = "rather than" 
Are they exchangeable in the following sentences?
1. Students discuss ideas, as opposed to just copying from books.
2. The media seems interested in his private life as opposed to his public life.
3. I think I'd like to stay at home this evening rather than go out.
but I am also confused about this sentence.
4. People have different views about the effectiveness of group study as opposed to working alone.
can "as opposed to" be replaced by "rather than", or "compared to" ?

Thank you very much.

Answer

In sentence 3, if you substitute as opposed to, you must also change the verb:
I think I'd like to stay at home this evening, as opposed to going out.
In sentence 4, you would be better to use "compared to".  You have correctly identified another slightly different meaning for the phrase "as opposed to".

Answer

You can use "as opposed to" to show contrast in matters. 
For example: 
"Apples as opposed to cheeseburgers, are lower in fat"

So essentialy, you should be able to substitute it for phrases that compare.