... do Golden Dawn Magicians gather?"
Information or data collected by Golden Dawn Magicians is for their spiritual practice and is symbolical in nature. In magic, the symbol is sovereign as a unique tool to communicate with the deeper layers of the human mind, setting into motion the true spiritual life of the Magician.
With the proper choice of symbols, the Golden Dawn system of Magic suggests to the deep layers of the mind the path to take and the energies to awaken suitable for the awakening of the Divine Spark of the human being.
This data is gathered from the symbol system coagulated for centuries around the structure of the Qabalistic Tree of Life, so that it may form a unique corpus of knowledge, perfect to discover and guide the magician through the Inner Planes lying beyond the world perceived by the senses. A Magician learns these symbols, and learns to use them to enter into communication with the deep mind and to develop the energetic body.