Traditionally, recursion is primarily taught using coding activities, presenting a high cognitive load for novice programmers. A possible method to teach recursion to novice programmers is the use of unplugged activities, engaging tasks not involving coding. Despite having been shown to improve students’ understanding of computational thinking, it has been argued that unplugged activities alone are not effective to teach recursion. In response, the authors engaged novice programmers who are non-computer science students by utilising unplugged visual activities to illustrate basic recursion concepts. Thereafter, the students were shown how to implement the activities with coding. The authors created three activities that illustrate recursion using breadth-first search (BFS) and depth-first search (DFS) algorithms. An evaluation study with 19 students was conducted in an on-line teaching environment. Empirical results show that most students learned the covered activities. Further, the students reported that the activities were engaging, and helped them learn how to think recursively
