With increasing expectations and new standards, it can be tempting to throw everything (including the proverbial kitchen sink) at our students. Doing so may, in fact, hinder learners’ understanding of a topic and have the opposite of the desired effect. Instead, by applying research-based strategies, we can ensure that even complex topics are presented in a comprehensible manner. Today, we will take a look at Cognitive Load Theory and how to use it to maximize the efficiency of both instruction and materials to facilitate learning.
Cognitive Load Theory
Previously, we learned that the Working Memory is vital in learning but limited in its capacity. Cognitive Load Theory attempts to account for the limitation of Working Memory by recognizing that learners can only process so much information at a time and attempting to adjust instruction accordingly. The Total Cognitive Load of a learning episode, or how taxing a task is on the Working Memory, can be described by the equation:
Intrinsic Load + Extraneous Load + Germane Load = Total Cognitive Load
The Intrinsic Load of an activity is the inherent difficulty or complexity of the information to be learned. Basically, the Intrinsic Load of a task boils down to how much information the students must process in their Working Memories at one time. Consider, for example, the two mathematical terms defined below:
- A two-way frequency table shows data from one sample group as it relates to two different categories.
- A unit fraction is a number that represents one equal part of a whole.
In this example, the first definition has a higher intrinsic load, not because it simply has more words, but because there are five elements to the definition that must be considered simultaneously in order to fully understand the term. The second definition places a lower intrinsic load on the student, as it consists of fewer elements that need to be processed in order to comprehend its meaning.
Because the Intrinsic Load is a quality of the task itself, it cannot be manipulated in any way. However, being aware of the Intrinsic Load of the information presented to learners is important, as instruction can be modified to account for tasks with varying Intrinsic Loads.
Extraneous Load is any demand placed on a learner unrelated to the information to be learned. Unlike the Intrinsic Load of a given activity, the Extraneous Load can be manipulated to make learning more efficient for students. When considering the Extraneous Load of information, there are two variables to be aware of: presentation of information and instructional strategies used.
Presentation of Information
Presenting material to learners in a clear, concise manner is crucial in limiting the Extraneous Load. Overloading materials with information that is not relevant to the learning goals (e.g., unnecessary images, redundant or overly-complex wording) distracts the learner and increases the Extraneous Load, having a negative effect on learning. Consider the two definitions of unit fractions below:
- A unit fraction is a number that represents one equal part of a whole.
- A unit fraction is a fraction 1/b formed by 1 part when a whole is partitioned into b equal parts.
Both definitions define the same term, however, the second term includes elements that increase the Extraneous Load (e.g., inclusion of variables), without adding to the clarity of the definition. For that reason, the first definition is more appropriate to present to students.
Similar to the presentation of information, the strategies an instructor uses can contribute to the Extraneous Load of a learning episode. As an instructor, it is critical to ensure that, during a lesson, all information is on topic and contributes to the desired learning goals. It is equally important to monitor redundancy to limit the information that is repeated unnecessarily. This is not to say that reteaching should never occur in a classroom. Reteaching is a useful strategy when students need more clarification. However, when learners understand a topic, hearing it repeated excessively can have a negative impact on learning.
Germane Load is the portion of the learning that is directed at schema construction. With information presented in a manner that promotes Germane Load (both in materials and instruction itself), learners can construct new or build up previously constructed schemas (complex categorization of information). Construction of schemas allows learners to interact with complex information without overloading their Working Memory.
Consider, for a moment, the term classroom. Despite the many elements of a classroom (e.g., desks, students, whiteboard) you can bring a mental picture of a classroom into your consciousness with relative ease. You are able to do so because, over time, you have constructed the schema of a classroom, allowing you to bring a fairly complex categorization of information into your working memory as one entity, rather than having to access and interact with each element of a classroom individually.
This third variable in Cognitive Load Theory is unique, in that the goal during efficient instruction is to increase Germane Load. Essentially, Germane Load can be considered the “good load,” and should be increased to promote learning.
Managing Cognitive Load in the Classroom
Worked Example Effect
A worked example is simply a step-by-step demonstration of how to perform a task. In early stages of learning a new task, worked examples are an effective instructional strategy for developing problem-solving skills in learners. Worked examples are most effective when the instructor models his or her thought process and emphasizes features of the problem that are related to the most efficient problem-solving method. The former provides learners with an expert explanation of the problem-solving process, minimizing Extraneous Load. The latter increases the Germane Load of the learning episode and makes schema construction more likely. Worked examples are utilized with this in mind in the Explicit Direct Instruction principle of the Rule of Two.
Expertise Reversal Effect
An interesting caveat to the Worked-Example Effect is the Expertise Reversal Effect. While worked examples are helpful for novice, or inexperienced, learners interacting with new material, worked examples that are too simple can have a negative effect on expert learners with prior knowledge on the topic. For a learner who already understands how to solve a problem, worked examples become unnecessary and only add to the Extraneous Load. For that reason, it is important to be aware of how much prior knowledge learners have coming into a lesson. It is equally important to monitor learners’ progress during a lesson, as, even with novice learners, too many worked examples can become redundant, leading to negative effects. In an Explicit Direct Instruction lesson, this is addressed through the slow release, where worked examples become progressively less guided by the instructor.
Split Attention Effect
The Split Attention Effect describes the increase in Extraneous Load when learners are required to direct their attention to two or more items simultaneously. A visual representation of the Split Attention Effect is shown below:
In Figure 1, the learner’s attention must be shared between the diagram and text below, unnecessarily increasing the Extraneous Load. In Figure 2, the diagram and the text are integrated, so the learner’s attention is not split and would be more likely to facilitate learning.
The Split-Attention Effect can also occur in auditory information. Dual narration of a single item can distract a learner and make it difficult for attention to be placed on all relevant information being presented.
During practice of a procedure, problems should include different variants of the task. By providing learners with a variety of problem types, they are more likely to make generalizations about the task, leading to construction of schemas. Development of schemas will make it more likely that learners will recognize the task in future problems, even if the superficial elements of a problem are unlike those practiced.
Sweller, J., Merrienboer, J., & Paas, F. (1998). Cognitive Architecture and Instructional Design. Educational Psychology Review, 10(3). 251-296.
Sweller, J. (1988). Cognitive Load During Problem Solving: Effects on Learning. Cognitive Science 12, 257-285.