Self-directed learning (SDL) is the major educational aim to cultivate resilient and adaptive lifelong learners of the 21st century [1], where the “self” should be vested so that the student can adjust to new situations in the learning process [2]. This requires (a) specific SDL skills [3], and (b) the heightened capability to manage all the learning elements on one’s own, which, however, creates a severe bottleneck for novice students [4]. Because relating several mental items, while also guiding the learning steps, challenges one’s cognitive activities in making sense of the sub-material quickly enough [2,3]. Yet, the latter is the core of efficiency in SDL: task-relevant information processing in working memory, and memorizing respective results in long-term memory [5]. As this process directly depends on the cognitive load per moment - due to the limitations of human cognitive architecture - there is a high need to avoid the cognitive overload of the learner [5]. The problem is that although higher-order cognitive skills are inevitably needed in SDL to lead the learning, understand the material [3], and to memorize while completing assignments at the same time [6-8]. From the developmental perspective such a multilevel cognitive capability cannot be taken for granted in school age students [9,10]. Learners with weaker cognitive skills get more easily confused, not able to resist distractions, and therefore perform worse at memorizing the task-relevant items [11]. This aspect is important especially in novice students, restricting their as quick as in adults “online” processing [7,12]. Yet, most of the SDL suggestions have been given based on adults, while only few studies have been carried out with school-age students [3]. In spite of that, SDL requires more sophisticated learning strategies to be employed by the learners themselves [13]. This need to combine both: (1) domain information what the learner knows and what he/she needs to know to successfully carry out the learning tasks, and (2) procedural information how-to, in order to adjust if needed [5]. All this creates a remarkably higher cognitive load for learners in SDL compared to conventional learning methods, where the teacher orchestrates most of the operations, and therefore the cognitive load of learners is lower while processing the information pre-organized by the teacher [14]. However, if the cognitive load becomes too high, it directly hampers learning quality and the transfer of knowledge [4,5]. These aspects may impact young learners’ reaching a proper final conclusion [2]. On the other hand, differences have been found also in the cognitive control function between boys and girls [10]. In light that SDL lays the ground for other competencies essential for educational growth and lifelong learning, it is reasonable to research this approach and its different corners [13]. Based on the findings given above, the current work concentrates on adolescence-age students’ SDL outdoors using a small-group learning format that has been suggested to lower one’s own cognitive load [15].