The concept of 'cognitive load' refers to the total amount of mental effort being used in the working memory. In educational psychology, cognitive load theory suggests that learning is most effective when instructional materials are designed to minimize unnecessary cognitive load, thereby freeing resources for schema acquisition. However, recent research has challenged the assumption that reducing cognitive load always enhances learning. For instance, a study by Kalyuga and colleagues found that for learners with high prior knowledge, certain forms of guidance (such as worked examples) can actually create a 'expertise reversal effect', where the guidance becomes redundant and interferes with performance. This indicates that optimal instructional design is not universal but depends on the learner's level of expertise. Consequently, adaptive learning environments that adjust the level of scaffolding based on individual progress may be more effective than static materials.