They viewed the Force differently and awaited a way to find "it". It being the true way to wield the Force.
They had a very monastic lifestyle and were viewed as isolationists.
Unfortunately, they were killed by the Sith at The Graveyard.
Behind the Scenes
Sisong is Gnosis backwards and the "it" the Learners wished to fine was something important to the Gnostic faith, which the user who created this does not believe, but thought it would be great to add for story value.