The tutorial model is suitable for giving feedback to individual learners, avoiding the risk of causing embarrassment or intimidation if the feedback is made available to everyone. Overall, however, the co-operative model is probably the most beneficial for the learner. It encourages collaborative learning supporting Vygotsky and Feuerstein's belief that 'the secret of effective learning lies in the nature of the social interaction between two or more people' (Williams and Burden, 1997: 40). The co-operative model also provides excellent opportunities for students to participate in stimulating task-based activities.