A few weeks ago, I was complaining that the version of instructional theory I knew did not reference specific mechanisms of cognition (Help Wanted: Linguist Seeking Cognitive Components). But my horizons recently got expanded to include Cognitive Load Theory. Actually I first found it in The Cambridge Handbook of Multimedia Learning (Chap 2) in an article written by John Sweller. The key concept I like

Learning has been defined as an alteration in long-term memory. If nothing has altered in long-term memory, nothing has been learned.

Specifically cognitive load theory says that knowledge (I assume facts/procedures in this case) is stored with some organizational structure attached (possibly all hierarchical schemas or schemas plus other structure). In contrast, new information has to be filtered through working memory (a type short term memory) Sweller proposes that when receive information, the working memory will try to get to a schema from long term memory to reduce cognitive load (I would say you try to recognize first, then learn new information). Interestingly, he proposes that if the learner’s memory can’t get a schema, the learner may first try to see if another person has one available (an instructor, a peer or the textbook). This fits the social aspect of learning, but it slightly contradicts the constructivist approach in that constructivism does not really assume that the learner is looking for a close match internal content organization. They assume the learner is constructing everything from scratch. On the other hand, if the learner already has a schema in place it is easier to process new additions (the more you know, the easier it may be to learn more). On the other hand, CHANGING a schema to fit new information can be pretty tricky. Some non-intuitive predictions I found interesting

• Redundant/duplicate information adds cognitive load – because you have to process ALL the material before you can determine it was duplicate. Instructional designers sometimes advocate showing the same information multiple ways to help different learner types, but you can get into overkill territory if you’re not careful (been there, done that)
• Worked examples critical – Sweller cites research that learners may need to see fully worked example problems to best learn the technique. Asking learners to "recreate" a technique from scratch may not be as productive. On the other hand, you do have to help learners transition to solving their own problems. Interestingly, although Sweller does not address the creative arts, it is interesting to note that art is usually taught by showing many examples of how a "design problem" is solved.
• Experts actually store a lot of "factoids" – But Sweller contends that experts index factoids in such a way so that they can recall the correct one given a current problem they’re solving. It’s different from being able to recite a random list of trivia. But you still need to get the factoids in there at some point…

I think this theory is on the right track, but there are a few valid criticisms I think a constructivist could make:

• There is no overt role for motivation or emotion – although I generally feel that motivation is something that either enhances or interferes with the ability of learners to place content in long term memory. However, a complete model should take this factor into account somehow, and I actually think a model like this could easily accommodate affective factors as a factor affecting memory storage.
• Assumes all hierarchical schemas – Actually I think this is what the EXPERTS store (but only "left brained" knowledge). Novices may be storing facts as "unstructured lists" and need help sorting what they know into appropriately structured schemas. Still some creative processes involve a "subconcious" or "right brained" mulling of the problem with strange tangents that is not well understood.
• Cognitive load theory may be more math/science geared – That is his focus is on learning a set body of facts and procedures. He does not really address issues like creativity in the arts or multiple points of view in sociology. On the other hand, even policy studies rely on being able to interpret facts and figures.
• Does not acknowledge cultural differences – Even if people are born with the same brain, they don’t get the same upbringing. Conflicts between home culture and academic culture can interfere with learning (because of affective issue). Acknowledging cultural differences can enhance opportunities for learning (especially for the instructor)
  I suspect Sweller would NOT believe different cultures store knowledge with different mechanisms. Different cultures may have different schemas (e.g. the tropics subdivide fruits into "hot" and "cold" varieties for various reasons), but they’re still schemas!
• Does not acknowledge "inborn" learner differences – On the other hand, some people may wonder if such a thing exists!