Cognitive load theory was first introduced by John Sweller in the late 1980s. Since that time, an abundance of research has been conducted in the fields of cognitive psychology and education to examine the cognitive processes at work throughout the learning process and how individuals receive, process, and store information. The results of this research have had a significant impact on both the design and delivery of instruction in K-12, higher education, and corporate settings. Best-practices for designing presentations such as limiting the amount of text on a slide, including captions with images, and using simplistic color palettes can all be attributed to the cognitive load literature base. Further, this literature base is largely responsible for several best practices in instruction. For example, the worked-example effect can easily be explained through the "I Do, We Do, You Do" approach to instruction in which an instructor begins by working examples out completely and then slowly transitions into the learners working them independently (with several worked examples for reference).

• Definition: Cognitive load can be defined as the cognitive restriction on the amount of information that can be processed at any one time (Day & Goldstone, 2012).
• Working Memory is comprised of the cognitive processes necessary to process and organize new information. We can only process 3-5 bits of information at a time (Kirschner, Sweller, & Clark, 2006) and it is lost if not put to use within 15-30 seconds (Driscoll, 2005). The images below represent how we receive and then organize information into a schema to be transferred into long term memory.

• Long-term Memory is where we store information once we have organized large chunks into schemas. Content experts have developed multiple schemas and organized them along with schemas in other areas to create complex knowledge structures over time. Long term memory has unlimited storage. Once something is stored in long-term memory we never lose it, just the ability to retrieve it. Retrieval is a function of the way the information was originally coded and stored and how many links/connections are provided across other schemas during the encoding phase.
• Experts are able to reduce the demand on working memory with schema automation. That is, experts are able to complete complex tasks which require heavy processing loads because they are able to perform large chunks of the task without utilizing any working memory capacity (See The Curse of Expertise). This is similar to when you download a program "in the background" but continue to surf the web, work in PowerPoint, etc.

• Intrinsic Load refers to the inherent complexity of the concept being studied or task being attempted. This type of cognitive load has also been referred to as element interactivity which is dependent on the complexity of the "to-be learned" material and the learner's expertise. Simply stated, "How hard is the stuff we are doing? Are we talking physics or arithmetic?"
• Extraneous Load refers to the irrelevant and/or inadequate material presented in conjunction with the "to-be learned" material which requires the learner to expend precious working memory capacity on activities which are not directly related to schema construction. Examples of extraneous load include: unnecessary images and videos, an abundance of text on a slide, lack of guidance/direction for a task, and poorly formatted online courses.
• Germane Load refers to the mental activities devoted to constructing schema and automation processes as a result of the presentation or design of instruction. It is germane cognitive load which contributes to, rather than interferes with, learning. This is the type of cognitive load instructors desire to activate in their students: a genuine curiosity which leads to engagement and productive struggle with the material.
• Cognitive Overload occurs when the sum of the three types of cognitive load exceeds the capacity of an individual's working memory. The amount of cognitive load which equals overload will vary from one person to the next for a given topic. A content expert sitting in on a lecture in their field for example, would have a much greater working memory capacity than the students in the class.

• Eliminate extraneous load
  • Be intentional in designing your course and each lesson within it.
    • Tips for Improving Presentations
  • Be aware of the students' developmental level and plan activities accordingly.
    • As pointed out by Kirschner, Sweller, and Clark (2006), constructivist instructional approaches (See Constructivism) have significant limitations with novice learners and should be carefully designed and implemented. The novice learner's working memory is easily overloaded even when instruction is effectively designed and delivered using best practices. Therefore, placing novice learners in a situation in which they must be self-motivated, self-directed, and receive little guidance is not ideal and in fact can significantly hinder the learning process. This is because they still require large amounts of working memory to simply process the content and the logistical tasks associated with the activity itself depletes much of the working memory capacity.
• Minimize intrinsic load
  • Being that intrinsic load refers to inherent complexity of a concept, this is the area where you have the least control. However, by eliminating extraneous load and maximizing germane load, you will effectively make inherently complex tasks and concepts easier to comprehend.
  • Well-designed and structured lessons delivered consistently throughout the course allow students to focus their working memory capacity on comprehension of content and not on what they should be doing or how they should be doing it. This is especially beneficial when dealing with intrinsically complicated material.
• Maximize germane load
  • In planning the design and delivery of material, consider both the structure of information being presented and the cognitive architecture necessary to process that information.
  • Provide directions in both written and verbal form. Especially in online settings, recording a short video explaining an assignment and the criteria for success serves to ensure that students are exerting less cognitive resources in administrative tasks and more on constructing schema.
  • It is essential that instructors are attuned to the developmental level of their students. Instructional techniques that are effective for novice learners will not always be effective for more advanced learners. In fact, in many cases the redundancy of information which benefits the novice learner actually has a negative effect on the more experienced learner. This is known as the expertise reversal effect.
• Final Thought
  • In order to facilitate schema construction we must be able to break our content down into bite-sized chunks and be intentional about how we choose to deliver it. Remember, you are an expert in your field with extremely well-developed and complex schematic mappings of your content. Your students are incapable of processing information anywhere close to the way you do. The connections you have built over years of study and practice are not yet present in the your students' schemas.

Day, S., & Goldstone, R. (2012). The import of knowledge export: Connecting findings and theories of transfer of learning. Educational Psycologist, 47(3), 153-176.

Driscoll, M. P. (2005). Psychology of learning for instruction (3rd ed.). Boston: Pearson.

Kirschner, P. A., Sweller, J., & Clark, R.E. (2006). Why minimal guidance during instruction does not work: An analysis of the failure of constructivist, discovery, problem-based, experiential, and inquiry-based teaching. Educational Psychologist, 41, 75-86.