## Key Ideas > [!abstract] Core Concepts > > - **Multiple sources compete for same working memory resources**: Simultaneous presentation of identical information in different forms creates interference > - **Eliminate unnecessary and duplicate information**: Remove irrelevant content and avoid replicating necessary information > - **IKEA instruction principle**: Diagrams only, no redundant text that competes for processing capacity ## Definition **Redundancy Effect**: Decreased learning when information is presented simultaneously in multiple forms that compete for the same working memory resources, causing interference and reducing processing efficiency (Sweller, Chandler, Tierney, & Cooper, 1990; Chandler & Sweller, 1991). ## Connected To [[Cognitive Load Theory]] | [[Split-Attention Effect]] | [[Modality Effect]] | [[Transient Information Effect]] | [[Use Booklets]] --- ## Common classroom examples Redundancy appears in three main forms in classroom instruction. Verbal redundancy occurs when teachers narrate worked examples whilst writing them on the board. Sweller et al. (1990) found that silent modelling followed by annotation after completion reduces interference between visual and auditory processing channels. Reading slides aloud whilst displaying text forces students to process identical information through two competing channels simultaneously; students learn better when they read independently or listen, not both (Kalyuga, Chandler, & Sweller, 1999). Verbally describing fully-labelled diagrams creates unnecessary duplication when the diagram already communicates the information (Chandler & Sweller, 1991). Visual redundancy creates different problems. Written descriptions accompanying clear diagrams add interference when the diagram is self-explanatory (Chandler & Sweller, 1991). Decorative images in textbooks distract from learning content without adding instructional value (Mayer, Heiser, & Lonn, 2001). Classroom displays competing for attention during direct instruction fragment student focus (Fisher et al., 2014). Content redundancy wastes cognitive resources. Lengthy contexts in mathematical problems consume working memory without aiding understanding (Sweller, 2010). Multiple examples showing identical procedures without variation provide repetition without learning value (Paas & van Merriënboer, 1994). ![[SplitAttention4.png]] ![[SplitAttention5.png]] ## Implementation guidelines Reducing redundancy requires discriminating between what adds value and what creates interference. Irrelevant visuals distract from content without supporting learning. Teachers should avoid speaking over clear written instructions; selecting one channel prevents competition between processing pathways. Multiple sources presenting the same information differently create processing demands without learning benefit. However, some information must be preserved. Essential information should be presented through the most effective single channel. Non-competing explanations using different sensory pathways can enhance learning through the modality effect: spoken words paired with visuals work well, but written words paired with visuals create redundancy (see [[Modality Effect]]). ## Design principles Four principles guide the reduction of redundancy without eliminating necessary support. First, choose an optimal presentation mode. Present content in written or spoken form, not both simultaneously (Kalyuga et al., 1999). Second, prioritise clarity over quantity. A single, clear explanation produces better learning than multiple confusing ones (Sweller et al., 1990). Third, consider expertise level. Experts may need less explanation, whilst novices may find some apparent redundancy necessary (Kalyuga et al., 2003). Fourth, test whether elimination reduces understanding. If removing information does not impair comprehension, it was redundant (Chandler & Sweller, 1991). ## References Chandler, P., & Sweller, J. (1991). Cognitive load theory and the format of instruction. *Cognition and Instruction*, 8(4), 293-332. https://doi.org/10.1207/s1532690xci0804_2 Fisher, A. V., Godwin, K. E., & Seltman, H. (2014). Visual environment, attention allocation, and learning in young children: When too much of a good thing may be bad. *Psychological Science*, 25(7), 1362-1370. https://doi.org/10.1177/0956797614533801 Kalyuga, S., Ayres, P., Chandler, P., & Sweller, J. (2003). The expertise reversal effect. *Educational Psychologist*, 38(1), 23-31. https://doi.org/10.1207/S15326985EP3801_4 Kalyuga, S., Chandler, P., & Sweller, J. (1999). Managing split-attention and redundancy in multimedia instruction. *Applied Cognitive Psychology*, 13(4), 351-371. https://doi.org/10.1002/(SICI)1099-0720(199908)13:4<351::AID-ACP589>3.0.CO;2-6 Mayer, R. E., Heiser, J., & Lonn, S. (2001). Cognitive constraints on multimedia learning: When presenting more material results in less understanding. *Journal of Educational Psychology*, 93(1), 187-198. https://doi.org/10.1037/0022-0663.93.1.187 Paas, F., & van Merriënboer, J. J. G. (1994). Variability of worked examples and transfer of geometrical problem-solving skills: A cognitive-load approach. *Journal of Educational Psychology*, 86(1), 122-133. https://doi.org/10.1037/0022-0663.86.1.122 Sweller, J. (2010). Element interactivity and intrinsic, extraneous, and germane cognitive load. *Educational Psychology Review*, 22(2), 123-138. https://doi.org/10.1007/s10648-010-9128-5 Sweller, J., Chandler, P., Tierney, P., & Cooper, M. (1990). Cognitive load as a factor in the structuring of technical material. *Journal of Experimental Psychology: General*, 119(2), 176-192. https://doi.org/10.1037/0096-3445.119.2.176