We know that Jedi are recruited at a very young age. Anakin Skywalker himself was deemed "too old" to begin training at 9 years old. We also know that younglings are assigned in groups to a Jedi Master to begin their training, as we saw in Attack of the Clones and the Clone Wars TV series (I see it as an elementary school or something. A group of students assigned to one classroom and one teacher).
Obi-Wan Kenobi began training with Qui-Gon Jinn at 12 years old. I assume that before that he was considered a youngling.
We also know that in order to become a Jedi Knight, a padawan must take "The Trials".
So my question is: Is there a similar test or "trial" for a youngling to become a padawan, or apprentice? Do they just reach certain age and are assigned a Jedi Master to train one-on-one?