John Sweller did a lot of research in the area of technical education in the fields of math and physics.

One of his early and important discoveries was that the practice of assigning "problem solving' for learning was misguided. Sweller concluded that the cognitive effort required by conventional problem solving may not assist in the most important aspect of problem solving EXPERTISE -that is, Schema Acquisition.

In order to understand schema it is worth talking about research done by De Groot in the 1960's. De Groot was interested in the difference between less experienced and master chess players. He did not find any difference in the breadth or depth of their knowledge. The only difference between a novice and an expert was in their memory of realistic chess positions. A later study found that both types of players remembered configurations and sequences of moves in CHUINKS, there was little difference in the number of chunks. What set the masters apart from the less experienced was the chunk size - masters had much larger chunks of sequences and configurations than did the novice chess players. These chunks are what we now call Schema.
Schema acquisition is what John Sweller considered to be more vital to becoming a master problem solver, than actually solving problems.

This thought leads to the general Cognitive Load Theory. There are three components to it: Intrinsic, Germane and Extraneous cognitive load.

(1) Intrinsic cognitive load, which is imposed by the intrinsic characteristics of the content that is to be learned; (2) Germane cognitive load, which refers to the mental effort required to organise the elements of the content into a schema, integrate it into long-term memory, and automate its processing; and (3)Extraneous cognitive load, which does not contribute to the learning process (eg the mental effort required to block out loud music).
If the total cognitive load of the learning task exceeds the processing capacity of working memory, learning fails. This suggests that instruction should be designed with a view to reduce cognitive load and thereby avoid overload. . Sweller argues that focus on developing schema rather than overloading the brain with problem solving tasks(aka GERMANE LOADING) will result in a more efficient path to expertise in a subject and that AUTOMATION is required to achieve that expert state of understanding.

Almost all learning theory is derived from one or more of the following psychological schools of thought:
• Behaviourism
• Cognitivism
• Constructivism
• Connectivism

Cognitive Load is a theory derived from Cognitivism

While exploring design principals for multimedia learning Mayer and Moreno focused on Cognitive psychology and used Sweller's Split-Attention Principle with which I will enLIGHTEN you at a later point

The strength of Cognitive Load is that much research has been conducted on this theory, and there are experienced people who have paved the way for further research on the topic.

Also,Some of the concepts from the theory apply to my own learning style, so of course they seem legitimate! I am thinking of schema and element interactivity....which brings me to the weakness of the cognitive load theory

There are intrinsic weaknesses in the theory, which will affect Instructional Design, that stem from a Cognitive Load concept called ELEMENT INTERACTIVITY.
Let me start with the example first:
When we learn the symbols for each element in chemistry there is Low Element Interactivity. Each symbol stands alone, we simply memorize its intrinsic information.
On the other hand, understanding the chemical equations shown here involves HIGH Element Interactivity and requires a lot of learning which results in a high cognitive load.

Cognitive load that interferes with learning is a problem only under conditions of high cognitive load caused by high element interactivity.
So here is the kicker - Under conditions of low element interactivity, re-designing instruction to reduce extraneous cognitive load may have no appreciable consequences.
IT'S NOT WORTH THE TROUBLE!

What are the implications for online or blended learning?

One of the most enlightening principles that I have found will impact my own teaching style...the Split Attention principle which I mentioned earlier...

Let's start with an example of SPLIT ATTENTION: a group of students who viewed an animation
depicting the formation of lightning while also listening to a corresponding narration generated
approximately 50% more useful solutions on a subsequent problem-solving test than did
students who viewed the same animation with corresponding on-screen text consisting of the
same words as the narration. Sweller and his colleagues call this a
split attention effect.
Bottom line: Simpler is better when it comes to visuals with narration!

As a youngster when I was taking math courses I would freeze up on the WORD PROBLEMS - possibly if my teachers had listened to Sweller I could have avoided the terror of problem solving and learned to build Schemas instead!

There is some talk in the INDUSTRY that cognitive load theory is at an impasse. That some of the principles may not be FALSIFIABLE.

However, there are very practical, obvious take aways for teaching that seem to make sense - so I am not yet willing to toss this theory out.
And I will be looking for the POST COGNITIVE studies yet to come.

A list of works cited / resources used in APA format

E-Learning Provocateur: Volume 1Paperback – November 21, 2011
by Ryan Tracey