Cognitive load theory can guide approaches to learning. It is based upon an understanding of cognitive architecture, including memory.
Short-term working memory for acquisition of new information is limited. It is generally possible to keep only 5 to 9 separate pieces of new information from sensory input in working memory at any one time. Between two and four of these pieces can be processed simultaneously, and only for a few seconds. Almost all of this new information is lost after 20 seconds unless it is refreshed through review. Learners may go through multiple cycles of learn-forget before the new information gets into working memory.
Long-term working memory supplies information that is not limited to just a few items at a time. Information available from long-term memory becomes organized by schemas that can be complex but also automated. This is how expertise is applied. The expert has built up many informational items in long-term memory in organized patterns that can be recalled and applied quickly.
Novice vs Expert
Novice learners must first acquire simple ideas with limited information content. Novices are trying to process many new variables, and the possible combinations of those variables is a mathematical factorial, or combinatorial, multiplication, not simple addition.
Experts combine the simple ideas into complex schemas. They are automatically using extensive long-term memory banks, while the novices are struggling to process new information with short-term memory. Expert schemas reinforced though multiple usage speed the automated processing of large amounts of information. This explains why expert teachers can become frustrated with novice students.
Novices should start with simple problems with limited new data. For example, a novice learning acid-base balance can start with an example of respiratory acidosis, with the blood gas data already interpreted. At higher levels of learning, more variables and unknowns can be introduced into problem sets. Learners should seek out methods for schema construction.
Van Merrienboer JJG, Sweller J. Cognitive load theory in health professional education: design principles and strategies. Med Educ. 2010;44:85-93.