In a "survival kit" published a few years ago, Ms Allison drew attention to the "rewards from being a regular class teacher . . . as a student you are a great novelty, as the class teacher you build up a relationship with your pupils that goes far deeper and lasts much longer.
She also believes, however, that moving from school to school provides an opportunity to "window-shop" and may give the supply teacher an advantage in landing a permanent job.