According to information processing approach in short term memory or working memory little information is stored for short duration which by rehearsal is converted into long term memory. In long term memory huge information is stored which can be retrieved over the years. Information processing done by working memory depends on cognitive abilities. Cognitive capability of working memory is narrow so if learning task has too much capacity learning will be hampered. We are persistently bombard with tons of information in our sensory memory through all five sense, only that information which we pay attention to is converted in to working or short term memory.
In working memory 3-4 bits of information lasts for 10 seconds only. It has finite capacity. This information by rehearsal and retrieval is transformed into long term memory. Long term memory has infinite capacity. Information here is stored as organized and structured knowledge called schemas. Basically interaction in both ways is going on, new information from working memory goes in the form of new schemas into long term memory and pre existing knowledge from long term memory is brought into working memory to comprehend the world.
So for intricate tasks cognitive overload that is total amount of intellectual commotion imposed on working memory at instant is reached soon. When this load exceeds capacity of person‘s working memory processing information, further learning is restricted. Because learning occurs when information is processed and moved from working memory into long term memory where it is proficiently stored. There are two types of cognitive overload intrinsic cognitive overload defined by complexity of subject matter it can be altered by instructional methods like dividing the content. Chandler and Sweller argue that staging design that incorporates diagrams decreases cognitive load.
Extrinsic cognitive overload occurs due to poor learning designs or instructional material that does not directly contribute to schemas formation. It can be prevailed over if material is presented in integrated way. This phrase is also explained in terms of Vygotsky’s cognitive development theory. It postulates that social communication is elementary to cognitive development.
According to Vygotsky learning should be done in zone of proximal development which means that individual cognitive skills are in process of growing and can be accomplished only with aid of more skilled persons. This theory tells us learning is a sequential process from simple tasks by working on your own to complex tasks with assistance of capable instructor to decrease intrinsic cognitive overload. This is done by scaffolding that is changing level of support from direct to indirect which helps students to learn independently
Its practical implications are instructional courses where either the context is so complicated or trainer went through content so rapidly that there was hardly any learning. So we have to formulate instructional designs which optimize the use of working memory. This is done by measuring expertise of students and asks their familiarity and use Bloom taxonomy model.
Effectual instructional designs essentially connect lower level schemas to higher level schemas hence new schemas are programmed by referencing to schemas of preexisting understanding. The gap between taught situation and desired goal needs to be reduced. Also split attention effect needs to be eliminated and effective usage of auditory and visual channels to facilitate working memory.