The current research revealed a disordinal aptitude-treatment interaction between learning style and mode of training. Over the course of several tutorials, 157 students were randomly allocated to one of the two teaching methods: face-to-face or on-line. At the end of the tutorial, students' learning was assessed using a short multiple-choice test and their learning style determined via Honey and Mumford's Learning Style Inventory. Results showed that more interactive learners (Activists and Pragmatists) performed better in the face-to-face condition compared to the on-line condition, whereas more independent learners (Theorists and Reflectors) performed better in the on-line condition compared to the face-to-face condition. This result suggests a psychological reason why on-line delivery of material has not superseded traditional face-to-face teaching methods, as prophesised by some commentators during the 1990's. Traditional face-to-face teaching and modern on-line delivery of material are complementary, each suited to the needs of different learners and neither replacing the other.