The local bishop is the first and main authority in apparition
cases, which can be defined as instances of private revelation.
Bishops evaluate evidence of an apparition according to these
guidelines:
1. The facts in the case are free of error.
2. The person(s) receiving the messages is/are psychologically
balanced, honest, moral, sincere and respectful of church
authority.
3. Doctrinal errors are not attributed to God, Our Lady or to a
saint.
4. Theological and spiritual doctrines presented are free of
error.
5. Moneymaking is not a motive involved in the events.
6. Healthy religious devotion and spiritual fruits result, with
no evidence of collective hysteria.
Judgment can find that an apparition shows all signs of being an
authentic or a truly miraculous intervention from heaven, that it
is clearly not miraculous or there are not sufficient signs
manifesting it to be be so, or that it's not evident whether or
not the alleged apparition is authentic.
If a Marian apparition is recognized by the bishop, it means that the message is not contrary to faith and morals and that Mary can be venerated in a special way at the site. But, because belief in a private revelation is not required by the church, Catholics are at liberty to decide how much personal spiritual emphasis to place on apparitions and the messages they deliver.