The search for assessment procedures that are more fair and useful have led to the investigation of alternatives to traditional forms of intellectual assessment. This study explored an alternative which combined a dynamic assessment approach with the Planning, Attention, Simultaneous and Successive Processing (PASS) model of cognitive processing. The aim was to investigate the effectiveness of a planning intervention programme based on Feuerstein's criteria for Mediated Learning Experience (MLE) with a group of Grade 4 and 5 remedial school learners who presented with a range of barriers to learning. Twenty six learners were assigned to the experimental group and 25 to the control group. The results showed that there was a significant improvement in the experimental group's Planning Scale score on the Cognitive Assessment System, following the intervention. These results imply that children often have far greater potential than is realised and that intentional mediation can help to enhance cognitive functioning and assist in further developing children's learning potential.