Cognitive Load Theory: The transient information, split attention, redundancy, and modality effects

The transient information, split attention, redundancy, and, modality effects

Cognitive load theory is a model of human cognition that splits the way we learn into two parts, working memory and long-term memory. 

Working memory can be described as out conscious thought at any moment in time, and is limited in two ways; it is restricted to about four items (+/- 1 or 2) at any one time, and has a limited duration in that once something else has our attention the information is gone.

Long-term memory is where information that we have memorised is stored as schema.  As we learn and memorise new item of information, we build these new items into existing schema and in this way schemas in long-term memory grow into multidimensional ‘chunks’.  Importantly, there is no known limit to how many or how complex schemas can be.

The power of having information in the form of schemas in long-term memory is that schema in long-term memory can be drawn into working memory and only take up the space of four items.

Cognitive Load Theory: A Model of Cognition

Research into cognitive load theory has identified many implications for instruction called ‘effects’ (such as the worked example effect which I have written about here).  In this blog I want to discuss four of these effects which I think every teacher can apply to their instruction all of the time.  These effects are the transient information effect, the split attention effect, the redundancy effect, and the modality effect.

The Transient Information Effect:

The transient information effect occurs when learners are being asked to integrate multiple items of sequential transient (spoken or video) information. In this case the item and duration limits of working memory are exceeded. Earlier information disappears from the learners working memory and therefore can’t be integrated with the more recent information being presented.

The Split Attention Effect:

The split attention effect occurs when learners are being asked to direct their attention to two or more sources of information that are separated by space (in different locations) or time.  A good example of this is having to flip backwards and forwards in a book to understand something.  The limits of working memory are exceeded because learners have to hold partial information in working memory whilst they switch, and then integrate another source of information.

The Redundancy Effect:

The redundancy effect occurs when learners are presented with information which is not related to the intended learning, or when presented with duplicates of essentially the same information.  Valuable working memory capacity is used as learners either search for connections between relevant and irrelevant information, or attempt to integrate the same information simultaneously.  An Example of when the redundancy effect occurs is when a teacher reads verbatim notes from a PowerPoint slide.

The Modality Effect:

Working memory appears to have two channels, one for auditory information and anther for visual information. These two channels are not isolated, but work together when processing and integrating new information.  When these auditory and visual channels are encoded together (called dual coding), a ‘double trace’ aids later retrieval.  In addition to this, when done effectively working memory capacity can be increased (but not doubled).  There are some important caveats to ensure that dual coding is applied effectively.

·      The auditory and visual information must rely on each other effectively

·      The information complexity needs to be high.

·      The auditory component needs to be short enough to be processed in working memory.

If you want to learn more about the modality effect then I suggest getting hold of a copy of Dual Coding With Teachers by Oliver Caviglioli.

Application:

The cognitive load theory effects describe above can be applied to instruction using the following principles:

• Focus: Have a laser-sharp focus on what you want your students to learn for a given lesson, or sequence of lessons.
• Cut and Declutter: Once you have focused on what you want your students to learn remove (or avoid adding) any information that is redundant and has the potential to unnecessarily exceed working memory limits.  Then declutter and simplify the presentation of information.  I have written about this process here.
• Reduce Transient Information: Ensure that all key transient information is recorded permanently for students to access.
• This includes any videos or animations.
• Add Modality: If it makes sense to, add simple diagrams and present information in the form of knowledge organizers.  In general it is better to avoid cluttered photos or busy videos because these include a lot of redundant and distracting information which take up valuable working memory capacity.
• Synchronise and Reduce Transiency: Present all relevant information at the same time, and ensure that all key information is written down for learners.  Then make sure that any verbal explanations are directly relevant to what the visuals that students are looking at.  It is important that any verbal explanations are kept short (ideally short enough to be only one element in working memory).

Applying the transient information the split attention, the redundancy, and the modality effects

See here If you want to learn more about cognitive load theory

I hope you find this blog post useful.

Dan (@dan_braith) 

The Worked Example Effect

The Worked Example Effect

Before I spent a good chunk of last year reading about Cognitive Load Theory I would find myself falling into the trap of telling my physics students who are struggling to do more problems.  It is probably in part due to the pervasive view in education that it is always better if a student figures something out for themselves (if the student discovers it). 

The worked example effect (one of the many ‘effects’ that have come out of research into Cognitive Load Theory) stands opposed this the view that it is always better for learners (and particularly novice learners), to discover something for themselves, and suggests instead that it is always better for a learner to be presented with multiple clear, well-structured and logically sequenced worked examples.  Simply put, novice learners benefit more from studying worked examples than spending the equivalent time on problem solving.

The reason that the worked example effect is more effective than problem solving comes down to schema, and the way that experts and novices approach problems.  When experts are faced with a novel problem they use existing schema, which is a large store of procedural and content knowledge in long-term memory that they draw on.  This leads to automated complex thought processes where the correct set of moves to make seems clear.  The experts understand how and why they have achieved the goal.

In contrast novices, when faced with a novel problem, tend to start by focusing the goal (in physics this is finding the answer), and then work backwards using means-end analysis.  A nice example of means-end analysis is finding your way through a maze for the first time, using trial-and-error to find a path through the maze. You may achieve the goal, but not know how or why you got there.  This process puts extraordinary burdens of working memory, and often means that students fail to build schema beyond the surface structure of a problem.

Problem Solving: Novices vs Experts

I think you can see this happening where students appear to be successfully solving lots of problems in class and at home, but in a test or exam can’t solve similar problems. What is happening is the students are using means-end analysis problem solving techniques for each question, eventually solving the problem, but not having a clear idea of how or why they solved the problem.  They are essentially memorising how to solve a variety of different problems, without building a strong schema of understanding.

The goal then, when providing students with worked examples, is to build expert schema (a large store of procedural and content knowledge).  This is only achieved if the worked examples reduce the students extraneous cognitive load.  The worked examples have to be clear, well structured, logically sequenced, and expose expert schema.

Its not enough to provide students with example after example, lesson after lesson, because there is no way for you as a teacher to check for understanding; to check that schema has been built, so time needs to be allocated for students to work independently on similar questions, and for teachers to use this time to check and correct student understanding.

In my teaching practice I have found that finding time to check for understanding has been difficult, as a complex worked example could take the better part of a lesson, when allowing for my explanations and student questions along the way.  To overcome this I have been providing pre-written worked examples that I discuss with the students in class.  I find that this takes about half the time that doing the same question on the board because I don’t have to write the information down, and I don’t have to wait for students to catch up with their notes.  I have also observed the following advantages:

• Students can focus on how the question was answered, rather than copying down notes.
• When one student answers a question, all students hear and engage with the answer, rather that just those who are caught up with their notes.
• The example is laid out in a way that I would do it, and no information is lost whilst students are copying off the board.

Below are some examples of my pre-written worked examples.  I think that the steps taken to solve a problem need to be clearly identified, so I sequence my examples using the steps I took as headings.  I also provide explanatory notes to clarify where I feel that this needs to be written down.

Electric Fields Worked Example

Magnetic Fields and Forces on electric currents/charges

See here If you want to learn more about cognitive load theory

I hope you find this blog post useful.

Dan (@dan_braith) 


References:

Clark, R.E., Kirschner, P.A., Sweller, J. (2012). Putting Students on the Path to Learning: The Case for Fully Guided Instruction. American Educator, v36 n1 p6-11 Spr 2012

Sweller, J., Ayres, P. L., & Kalyuga, S. (2011). Cognitive load theory. New York: Springer.