You are NOT exhibiting mediumship when you describe the person you are connecting with in the spirit world. That is clairvoyant/clairsentient ability. No matter how accurately descriptive you are of that person it still isn't mediumship.
This is one of the big misconceptions in the psychic industry at this time. Spiritual teachers, make sure you point this fact out to your students.
When the person on the other side commences conversaiton with you via clairaudience this is the first steps to it becoming a mediumship connection.
Once you know who it is that is communicating with you and why (They do not come through for mundane reasons such as being there or just saying hello) ... then it starts to become a mediumship connection.
Mediumship is a clear two way connection between you and the person on the other side. Any connections between you and a intermediary (Guide, supposed angelic or ascended source) is NOT mediumship.
The industry is blighted with mis-understood definitions.
Only 5% of all assumed mediumship connections are actually mediumship - FACT.