## 1 Introduction
### Cognitive Load Definition and Measurement  
In recent years, the measurement of cognitive load with respect to task performance or problem solving has become a necessary process, as it helps us understand performance and facilitates an analysis and adjustment of how tasks or problems are presented. Interest arises from a variety of fields and contexts (the educational and instructional sector, marketing, driving, aviation, business, etc.). However, there are many challenges involved in what seems at first to be manageable. The concept of cognitive load is based on the idea that cognitive resources are limited. Cognitive load develops as a complex interaction between the different demands of tasks and the cognitive processes required to process and execute them, and a subject'sperformance often decreases when cognitive demands are either very low or very high. The techniques for measuring cognitive load can be classified into four main categories: (1) performance-based, (2) subjective, (3) behavioural and (4) physiological [1; 2; 3]. Performance can be measured through learning outcomes, subjectivity through learning history and the use of scales, and behaviours through behavioural analyses. When it comes to physiological components, various indicators can be applied to measure physiological responses during task performance or problem solving. For example, research using eye tracking technology shows that the frequency of fixations, saccades and pupil diameter appear to be suitable indicators for predicting task difficulty at an early stage [4]. The theory of cognitive load is related to studies in the field of developmental educational psychology and instructional cognitive psychology, specifically the study of the relationship between working memory and long-term memory (LTM) [5]. The theory first appeared in 1976 with [PERSON]'s studies [6]. Subsequently, in the late 1980s, the concept of cognitive load was used to explain performance on different tasks with respect to the use of various forms of information processing. A distinction was made between the intrinsic cognitive load (which refers to the complexity of the knowledge to be processed by the learner and is independent of how the task is presented) [7] and extrinsic cognitive load (referring to how the task is presented) [8; 9]. Cognitive load seems to be related to divided attention with respect to information received through different channels (visual, auditory, or both). This information must be integrated in order for the learning agent to gain an understanding of a task [9; 10]. The comprehension process also seems to be influenced by the way the task is presented [11]. These results are based on [PERSON]'s theory [12], according to which memory is divided into different types of storage [short-term memory (STM), working memory, and LTM]. For [PERSON] [12], working memory consists of an auditory subsystem and a visual subsystem. Until the second half of the 1990s, research on cognitive load theory focused on instructional designs seeking to reduce the extrinsic cognitive load, since at that time the intrinsic load was difficult to measure or manipulate. Later, the concept of germane cognitive load was used to refer to the mental resources that learners deploy to deal with the intrinsic cognitive load of learning tasks [8]. It was introduced in reference to the development of cognitive schemas in LTM on knowledge integration. Subsequently, studies by [PERSON] [13] showed that integrating information through different channels (visual or auditory) does not always lead to better learning. The explanation was that eliminating redundant information can be beneficial in the learning process. [PERSON] tried to integrate cognitive load theory into the broader theoretical framework of evolutionary theory [13]. This new view was explained by a representation of the cognitive architecture in which there are different memory stores.