Problem Based Learning (PBL) has been shown to be effective from elementary school through medical school. This would be an excellent domain name for a site devoted to problem based learning in science, either as a sharing and reference site, or for a book, workshop, learning centre, etc. Problem based learning works, so can this domain name! The domain name is registered until summer 2018, and renews at standard .science TLD rates. The term PBL has excellent SEO stats and CPC value, and Estibot valuate the PBL.science domain name at $1600 - pick the domain name up here for a small fraction of that price! The name PBL is already taken in most extensions.