Vygotsky’s zone of proximal development is a concept that all teachers are well aware of. ZPD is that sweet spot that pushes learning beyond the comfort zone of what students can do on their own and provides them guidance from an expert to move them forward into new learning. The concept just makes sense. It inspired Jerome Bruner to develop the theory of scaffolding, another familiar teaching tool that forms one of the foundations of good teaching. Both ideas have proven to stand the test of time and are a cornerstone of teacher training. The significance of both is undeniable. However, there is another key theory that is unknown to many teachers. It is not usually taught in education programs, despite being just as (if not more) essential as ZPD and scaffolding.
Cognitive load theory suggests that learning happens best when it matches the abilities of our working memory. It refers to the total amount of mental effort being used in working memory, where new information is processed. Unfortunately, it is limited. We can only process between 4-6 items at a time, and the information in working memory lasts only around ten seconds. If you think of solving a math problem, where you are asked to remember multiple steps at a time, you can see how the limits of working memory can be a problem. It can quickly become overloaded. As a result, lots of information given to students can often be missed, as it is not processed by a working memory that is overwhelmed.
The good news is that we have a huge storage capacity in our long-term memory which is like the hard drive of a computer. Once something is stored as schema in long-term memory, it is easy to retrieve and use. The construction of schemas in long-term memory and their development into higher-levels that become automated is what helps students to increase their expertise in any given area. It frees up working memory to process other information. The tricky part is transferring new learning from working memory and getting it to stick in long-term memory. Why was I never taught this in teachers’ college!? Its implications for learning are profound.
Cognitive load is divided into three types:
- Intrinsic load – refers to the inherent complexity of the learning material. Teachers cannot do much to reduce this load but it can be balanced. According to Sweller, it can ‘only be altered by changing the nature of what is learned or by the act of learning itself’. It is what it is.
- Extraneous load – any difficulty that comes from how the task was presented. Teachers should avoid the use of anything that distracts students and makes the learning process harder. It is the load to be wary of. Effective lesson planning can help rein it in.
- Germane load – this is the work that goes into creating schemas (permanent knowledge) and it happens when lesson plans and courses are well designed. This interesting post by Nick Rose explains in it more detail with links to studies.
In order to get students to maximize germane load and get into the struggle zone of effective learning (thinking hard, high challenge and low stress), some things we can do are: teach fewer concepts per lesson, chunk the learning, limit distractions, narrow the success criteria and procedures, avoid switching focus of attention, revisit material and use models and worked examples.
The importance of cognitive load and memory is something every teacher needs to consider. Many think of memory as rote learning, a linear stuffing of the brain with facts, where understanding is irrelevant. When you teach it properly, with imagination and association, understanding becomes a part of it.