The Sleep-Learning program, also called Celestial Learning, is based on the premise that bodies of knowledge presently unavailable to conscious awareness exist in the astral realm and can be acquired through spontaneous out-of-body travel during sleep. The program recognizes individual differences in rates of learning and the possibility of accelerating learning through out-of-body interactions during sleep with advanced learning specialists. 

Celestial Learning emphasizes two critical conditions related to out-of-body learning during sleep: 

1. Clearly formulated affirmations related to a specific goal (Example: I am becoming fluent in German), and 
2. Review during drowsiness on previous learning experiences related to the designated goal.  

The study found that students actively engaged in a variety of learning situations experienced a rapid improvement in the rate of learning as well as retention through Celestial Learning. The program, rather than directly inducing our-of-body travel, simply established the pre-sleep conditions conducive to spontaneous travel.