The value of critiquing alternative problem solving strategies.
In a traditional classroom, a task is often used by the teacher to introduce a new technique, then students practice the technique using similar tasks. This is what some refer to as ‘Triple X’ teaching: ‘exposition, examples, exercises.’ There is no need for the teacher to connect or compare alternative approaches as it is predetermined that all students will solve each task using the same method. Any student difficulties are unlikely to surprise the teacher. This is not the case in a classroom where students employ different approaches to solve the same non-routine task; the teacher’s role is more demanding. Students may use unanticipated solution-methods and unforeseen difficulties may arise.
The benefits of learning mathematics by understanding, critiquing, comparing and discussing multiple approaches to a problem are well-known (Pierce, et al. 2011; Silver, et al. 2005). Two approaches are commonly used: inviting students to solve each problem in more than one way, and allowing multiple methods to arise naturally within the classroom then having these discussed by the class. Both methods are difficult for teachers.