Habilitation (lat. habilis - fit, proper, skillfull) is the highest academic qualification a scholar can achieve by his or her own pursuit in several European and Asian countries. Earned after obtaining a research doctorate, such as a PhD, habilitation requires the candidate to write a professorial thesis  (often known as a Habilitationsschrift, or Habilitation thesis) based on independent scholarship, reviewed by and defended before an academic committee in a process similar to that for the doctoral dissertation. However, the level of scholarship has to be considerably higher than that required for a research doctoral (PhD) thesis in terms of quality and quantity, and must be accomplished independently, in contrast with a PhD dissertation typically directed or guided by a faculty supervisor.