1.3 Cognitive view: cognitive load theory

Cognitive load theory

The information-processing model has given rise to a theory of instructional design called cognitive load theory ( Sweller&Chandler, 1994 ; van Merriënboer&Sweller, 2005 ). Because working memory is the principal player in the process of learning new information, cognitiveload theory focuses exclusively on working memory. The gist of this theory is that there are distinct types of demands imposed uponworking memory during learning: intrinsic, extraneous, and germane. We now examine each of these.

Intrinsic cognitive load

Intrinsic cognitive load represents the burden imposed on working memory by the inherent nature of the material. In otherwords, simple topics require very little processing capacity in working memory, and complex topics demand a large amount of space.For example, it requires considerably more focus to safely drive a semi truck through a rainstorm than to sign your name with a pen onpaper. Driving the semi requires attention to many different information inputs (e.g., gauges, mirrors, windshield) andcoordinating the requisite motor skills in response; all of this processing is conducted in working memory. Signing one's name takesbarely any attention at all (for adults) because it has been done thousands of times before. Thus, the effect of having practiced theskill reduces its intrinsic cognitive load.

But practice alone cannot reduce the intrinsic cognitive load of all tasks. The element interactivity (i.e., coordination among multiple aspects) inherent in some tasks cannot ultimately reduce thetask to a trivial activity, even with extensive practice. If that were the case, we should all be capable of becoming skilled airlinepilots or successful politicians.

For beginners learning an essential skill, element interactivity becomes problematic and must be temporarily reduced. When learning alanguage, one first learns the alphabet and then proceeds to acquire simple words or phrases—not complex prose. But one cannot beconsidered proficient in a language unless one can understand its complex prose. This is an example of element interactivity becauseunderstanding prose depends upon not only understanding its nouns, verbs, adverbs, etc., but also how each of them modifies or alters themeaning of other words nearby. Topics or skills that contain element interactivity must at first be oversimplified and then gradually builtup to their full complexity before one can successfully deal with the intrinsic cognitive load.

Extraneous cognitive load

Extraneous cognitive load is the set of mental demands that are irrelevant to the current task. Recall the butterfly display thatwas distracting Pierre ( [link] )? The butterflies had nothing to do with the directions the teacher wasgiving Pierre's group, yet Pierre was distracted by his classmates on the other side of the room. His classmates' activity was extraneouscognitive load for Pierre because it was consuming his precious cognitive resources yet not providing any real benefit to him in thetask of understanding his teacher's directions.

It is critical to realize that these various forms of cognitive load are additive —that is, they each increase the amount of processing space that is active in working memory. For example, ifthe intrinsic load is already high, there is not much room for any extraneous load unless the learner decides (like Pierre) to reduce theprocessing of the intrinsic load and focus more on the extraneous load. Teachers should strive to reduce extraneous cognitive load intheir classrooms because students are likely to sacrifice attention to important material and distract themselves with the extraneousstimuli.

Extraneous cognitive load is, for the most part, under the direct control of the teacher. Have you ever seen presentations that weredecorated with graphics which were only tangentially related to the content? You probably found yourself sidelined by the images and notpaying sufficient attention to the material itself. Because working memory has such a limited capacity, we cannot afford to “clutter up”this valuable space with unproductive ideas that divert attention from more important content. As a teacher, you should make earnest effortsto avoid exposing students to extra “fluff” during learning activities.

Germane cognitive load

Germane cognitive load has been explained in various ways. The explanation I prefer is the more traditional characterization thatgermane load represents increased demand upon working memory in the service of the learning goal. This can be explained more easilythrough an example. Most (if not all) languages have forms of expression that are not appropriate for all audiences. For example,in English one would not address the President of the United States in the same informal way as one would address a close friend( “How is your day going, Mr. President?” versus “Hey dude, whazzup?” ). The meaning of the utterance expressed to these two individuals may be the same, but the words andintonation are somewhat different. If an international student were learning English, it would be important for the language teacher tocommunicate not only the meaning of the words (intrinsic load) but also the contexts in which those words are appropriate (germane load).Learning the situations in which certain phrases are most appropriately used goes beyond intrinsic load but could hardly beconsidered extraneous if one's purpose is to learn the language well.

It goes without saying that beginning learners should not be exposed to germane cognitive load; the intrinsic load for many tasks is ofsufficient complexity that beginners cannot handle any additional processing burdens. However, as learning proceeds and the intrinsicload becomes more and more automatized, teachers can add aspects of additional complexity that enhance students' understanding of thematerial in a germane way.