Approaches to discipline.

At a recent parent teacher conference I was informed by my 9 year old son's teacher that she had placed his single desk in the center of the class room, in an attempt to encourage good class behavior from him. The remaining students were stationed in groups or clusters of four each group at each corner of the room surrounding his isolated desk. The other 16 students were also instructed during the class period to "ignore" this student "when he lashes out." I was shocked to be hearing this for the first time at the conference as his teacher informed me that this was one of many "last resorts" to an ongoing problem. His teacher says that the kinds of outbursts she is noticing are things like not raising his hand to answer questions, switching the subject, creating distractions to get the attention of other students... I really wish I'd known there was a problem before the teacher went through two different methods of disciplining my son. By different I mean unusual to the standard methods used to encourage the other students in the class room. My question is in regards to this method, it seemed unusual and extreme to me but I'm not a teacher? I don't have to work with children in groups, is this a technique that is often used to correct or address behavior problems in the classroom?