Since the mid-1990s Bahá'í community life has been organised around a training institute process, most widely through the sequence of courses developed by the Ruhi Institute in Colombia. Participants work through a series of workbooks in small groups with a tutor — explicitly not a teacher — reading passages aloud, answering written questions and discussing, and each book culminates in an act of service: hosting devotional meetings, teaching children's classes, animating junior youth groups for eleven to fourteen-year-olds, or accompanying others through the same books. The design principle is replication without professionals: anyone who has completed a book is expected to be able to tutor it, so capacity multiplies without a trained cadre. Activity is organised in three-month cycles of expansion, consolidation and reflection within geographic clusters. The approach has been criticised inside the community as formulaic and as displacing other forms of intellectual life, and defended as the first method that produced sustained growth outside the faith's existing social networks. Either way, it is what Bahá'í practice mostly consists of now.