Here is an insightful article from Cambridge English Blog.
The Cambridge team says, “In Greg Archer’s recent webinar, the author of Mindset for IELTS looks at ways grammar and vocabulary can be developed so that your students can successfully demonstrate what they know and what they can do in their B1 Preliminary for Schools and B2 First for Schools speaking exams.
Error correction versus upgrading vocabulary
I remember clearly, during my CELTA teacher training course, learning about delayed correction. This is where the teacher, while monitoring students doing a speaking activity, makes notes of ‘incorrect’ use of grammar or vocabulary. At some point after, typically at the end of the activity, these notes are transferred onto the board and the appropriate revisions are made together as a class. This was an absolute revelation to me, and I applied it to my teaching with great enthusiasm. Over time, however, and with experience, I began to question how beneficial it is to rely on this method so heavily.”