## Key ideas > [!abstract] Core concepts > > - **Three load types**: Intrinsic (content difficulty), extraneous (presentation problems), germane (schema building) (Sweller et al., 1998) > - **Working memory limitation**: Working memory holds about four items at once (Cowan, 2001) > - **Management**: Reduce extraneous load, manage intrinsic load, then increase germane load (Sweller, 2010) ## Definition **Cognitive load**: The mental effort used in working memory during learning. Sweller et al. (2019) distinguish three types, each with different implications for instruction. ## Connected to [[Cognitive Load Theory]] | [[Memory]] | [[Element Interactivity]] | [[Part-Whole Approach]] | [[Scaffolding]] --- ## Three types of cognitive load ![[CognitiveLoad.png|400]] ### Intrinsic load Intrinsic load comes from the [[element interactivity|inherent difficulty]] of material relative to the learner's [[Prior Knowledge]] (Sweller, 1994). A Year 7 student solving simultaneous equations faces high intrinsic load; a Year 11 student who has automated linear equations does not. The load cannot be removed, but it can be managed. The [[Part-Whole Approach]] is the most direct method: break a complex procedure into smaller steps and teach them sequentially (Catrambone, 1998). Pre-teaching works similarly by automating prerequisite knowledge before the main lesson, so students are not learning two things at once (Mayer et al., 2002). In procedural learning, a snowball approach has students learn a new step, then complete all previous steps together, building fluency across the whole sequence (Renkl et al., 2002). [[Chunking]] helps too. Grouping related information into meaningful units reduces the number of items held in working memory (Miller, 1956). When intrinsic load is high, [[Worked Examples]] are useful because they show the solution process without requiring the student to problem-solve independently (Sweller & Cooper, 1985). Slower pacing and frequent checks for understanding also help, particularly with high element interactivity material (Sweller, 1994). ### Extraneous load Extraneous load is wasted effort caused by poor presentation (Chandler & Sweller, 1991). It contributes nothing to learning. Decorated slides, split-attention layouts, chaotic environments, distracting images: all consume working memory without benefit (Fisher et al., 2014; Mayer et al., 2001; Chandler & Sweller, 1992). This is the easiest type to address because it is entirely under teacher control (Sweller et al., 1998). Placing text next to the relevant part of a diagram, rather than separating them, removes the need to search and match (Chandler & Sweller, 1992). [[Use Booklets|Booklets and worksheets]] give students permanent reference material so they do not waste effort holding transient information from a slideshow (Leahy & Sweller, 2011). Removing decorative elements that lack pedagogical value reduces distraction (Mayer et al., 2001). Quiet during independent practice prevents auditory interference (Shield & Dockrell, 2008). Physical environment matters here too. Classroom noise affects attainment (Shield & Dockrell, 2008), poor ventilation impairs cognitive performance (Satish et al., 2012), and even dehydration affects brain function in adolescents (Kempton et al., 2011). ### Germane load Germane load is the effort of building and strengthening schemas, the mental structures that organise knowledge in long-term memory (Sweller et al., 1998). It is the productive part of cognitive load. The key constraint: germane load should only increase after intrinsic load is manageable and extraneous load is low (Sweller, 2010). Introducing complex problem-solving or interleaved practice before students have automated the basics produces confusion, not deeper understanding (Kalyuga et al., 2003). When students are ready, [[Retrieval Practice]] strengthens memory traces through testing and recall (Roediger & Karpicke, 2006). The [[Interleaving Effect]] forces students to discriminate between problem types rather than relying on blocked practice (Rohrer & Taylor, 2007). Asking students to explain connections between concepts strengthens schema development (Chi et al., 1994). Complexity should increase gradually (van Merriënboer et al., 2003). ## Common mistakes The most frequent error is adding germane load too early. Teachers introduce complex tasks or mixed practice whilst students still struggle with the basics, so intrinsic and germane load combine to overwhelm working memory (Sweller et al., 2019). A related mistake is skipping prerequisites: if foundational knowledge is not automated, students must learn and apply new concepts at the same time (Mayer et al., 2002). Decorative content is another trap. Fun images and jokes feel motivating but add extraneous load (Mayer et al., 2001). Teachers also rush through complex material without enough processing time, preventing schema construction (Sweller, 1994). The [[Curse of Knowledge]] makes all of these harder to spot. What feels simple to an expert whose knowledge is chunked and automatic can overwhelm a novice (Hinds, 1999). Teachers with deep subject knowledge routinely underestimate how much their students need to hold in working memory. ## Teacher cognitive load Teachers face the same working memory constraints as their students (Willingham, 2009). A lesson requires monitoring understanding, managing behaviour, delivering content, and adjusting in real-time. For novice teachers, who lack automated routines, this easily exceeds capacity. Expert teachers have automated most classroom management, freeing working memory for responsive teaching. They spot patterns in student behaviour that novices miss and anticipate difficulties before they arise. This expertise takes years of deliberate practice to develop. Planning is the main lever. Detailed preparation reduces in-lesson cognitive load by pre-solving instructional problems: anticipating misconceptions, preparing alternative explanations, sequencing content carefully. Teachers should also write down what works and what does not. Memory for teaching events fades quickly, and relying on recall alone means repeating the same mistakes. ## References Catrambone, R. (1998). 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