 According to Vetter it may not have been as effective as "dhyana", and methods were developed to deepen the effects of discriminating insight.Insight was also paired to "dhyana", resulting in the well-known "sila-samadhi-prajna" scheme.According to Vetter this kind of preparatory ""dhyana"" must have been different from the practice introduced by the Buddha, using kasina-exercises to produce a "more artificially produced dhyana", resulting in the cessation of apperceptions and feelings.