Transfer of learning, the application of learning to different contexts over time, is important to all learning for development. As 21st century skills specifically aim to be "generic," there is an assumption that they can be transferred from context to context. We investigate the process of transfer in problem solving, with specific focus on mathematical problem solving tasks. Problem solving is highly valued in 21st century workplaces, where mathematical skills are also considered to be foundational in STEM and of paramount importance. This study examines the transfer of first semester mathematics learning to problem solving in second semester physics at university. We report on: (1) university students' (n = 10) "think-aloud" accounts of the process of transfer; and (2) students' (n = 10) and academics' (n = 8) perspectives on transfer processes and problem solving. Think-aloud accounts show students' recursive use of interpretation, integration, planning and execution thinking processes and highlight the meta-cognitive strategies used in transfer. Academics' and students' perspectives on transfer show disparities. Understanding these perspectives is important to current initiatives to integrate and optimise 21st century learning within universities. We argue that renewed attention on the concept of transfer is needed if the generic aims of 21st century skills are to be understood and promoted.
Keywords: 21 century skills; interdisciplinary; mathematics; problem solving; science; think-aloud; transfer; university.