If I have an article that was already accepted and presented in a conference, and I would like to present it as an extended article to a journal, I was wondering two things:

  • How much paraphrasing should I use in my journal article?
  • How much "new" material should be added to the journal article?

I have found some articles in my field of Computer Science in which the quantity of added material from the original article was too scarce; and that the paraphrasing was also mostly nonexistent. It just looked like if they have added some parts only to make it to the journal. Or is it that in an extended article should I put what it was missing from the original one, i.e., limitations of space because of restrictions imposed by the conference regarding article's length.

By the way, I am considering the situation in which I submit to a journal not related to conference in which my article was previously submitted.