The medical model, where trainee doctors shadow a doctor as she goes about her rounds, has been adopted by two Boston colleges and their partner elementary schools in an attempt to get student teachers into as many different classrooms as possible.
As in the UK, Boston's trainee teachers used to spend almost all of their classroom practice with only one teacher-mentor. Initially, trainers tried to broaden students' experience by asking them to exchange classrooms for a week. They also asked pairs of students to team-teach in two classrooms.
But the "ward rounds" approach has proved most popular with students and schools, in a study carried out by Nancy Frane, a Massachusetts teacher.
Groups of three students can see as many as 16 different teaching styles during the course of a year. They can also attend 10 meetings to reflect on what they have learnt.
The system does not work perfectly. Some students feel that they need at least two hours in each classroom - rather than one. And some teachers have found the observations uncomfortable.
But, on balance, the model works. As one student kindergarten teacher said, the tour of classrooms was a reminder that "there is a whole other universe out there. Your own classroom can seem like a small world."
Correspondence: Nancy Frane, Edward Devotion School, Brookline, MA 02446