From About the Progoff Journal

One of the most powerful and distinctive features of the Progoff Journal is its use of Twilight Imagery, which is very close to what Jung called Active Imagination. After decades of using this method in my Progoff Journal, I was amazed when I finally dove into Jung’s Red Book, to see that that entire project was one huge exercise of what he later came to call Active Imagination. 

Ira Progoff brought Jungian Active Imagination out of Jungian Analysis and slipped it into use under the aegis of his journal writing workshops. Never calling it Active Imagination, Progoff made it the central method of intuitively analyzing one’s own diary-like entries into his special journal format. Workshop participants were (and still are after Dr. Progoff’s death), [shown] how to “sit in stillness” and move into “Twilight Imaging”:

“The key to Twilight Imaging lies in the fact that it takes place in the twilight state between waking and sleeping. We find that by working actively in that intermediate state of consciousness, we are able to reach depths of ourselves with which it is very difficult to make contact by any other means.” (At A Journal Workshop: The Basic Text & Guide For Using The Intensive Journal, pp. 77-78).

http://www.bodysoulandspirit.net/hypnagogia/what/progoff.shtml