The human brain is remarkable but it does have a limited working memory. It is often said that our short term memory is only able to process a small number of items for a very short time. Information fades quickly unless it is actively rehearsed or connected to existing knowledge in long-term memory. Learning depends on schema formation. This is the process of gradually building, connecting, and automatizing knowledge in our long-term memory. When instruction includes too much irrelevant or poorly timed information, working memory can become overloaded. For that reason, it is useful to think carefully about cognitive load and to reduce any mental effort that does not directly support learning.

Cognitive load is usually broken down into three different components. Intrinsic load is the element of interactivity of material that makes tasks challenging. It is the inherent difficult of the material which can only be managed by segmenting materials, isolating sub-skills into smaller steps. Extraneous load is considered to be bad load, since it is generally made up of instructional junk like poorly designed presentations, or conflicting elements that split the learner’s attention. This has to be rigorously avoided if any serious learning can happen. The mental effort involve in schema formation is known as germane load. This can only be increased if extraneous and intrinsic load are reduced.

Teachers often fall into the “more is better” trap, as learning materials become more dense. For example, a language trainer might provide an audio, a full transcript, an L1 translation, and a detailed grammar reference, all on the same presentation slide. The learner’s brain isn’t just processing the language, it is processing the relationships between the text, the audio, and the translation. It splits the learner’s attention between too many elements.

If the learner understands the audio, the transcript becomes redundant noise, information that they have to filter out. This is wasting energy that could be used for real learning. The redundancy problem happens when the learners are not challenged by material that they already encountered and know. They are being forced to read something entirely redundant to their needs, increasing their extraneous cognitive load. The problem is that this doesn’t just waste valuable mental space, it actively steals precious processing power from their working memory. It halts real schema formation.

One of the worst examples of the redundancy problem is listening to audio in your target language while reading the subtitles below. This might be interesting for a beginner learner who is unable to understand the text. What’s happening is that the auditory cortex and the visual cortex are processing identical data. This actually slows down listening fluency because the brain relies on the crutch of text, rather than training the ear to parse phonemes. If you read the subtitles, the audio becomes redundant background static.

Another example of split attention is the idea of providing L1 translation as a standard practice. If the learner knows 80% of the words in a text, then these translations are totally redundant. The eye is forced to scan them, creating visual clutter that distracts from the 20% of target vocabulary that is truly new.

A similar problem applies to communication tasks. For example, sentence stems, substitution tables, model answers, and vocabulary lists can be useful at lower levels or when learners are dealing with unfamiliar language. But for more proficient learners, too much scaffolding may become distracting or unnecessary. If learners have already automatized a structure, they often benefit more from tasks that require freer retrieval and production.

This is why adaptive support is so important. Subtitles, translations, grammar explanations, and other aids should not always appear by default. Provide them only when learners genuinely need them. One useful approach is graduated support where, if a learner struggles, they first receive a brief prompt or simple rule, followed by a fuller explanation only if difficulty continues. If they complete the task successfully, the extra explanation can remain hidden because it would add little value at that moment.

Teachers can also watch for signs that support is mismatched to learner needs. If learners complete a gap-fill task very quickly and accurately, the task may be drawing on knowledge that is already well established, so a less scaffolded activity may be more appropriate. On the other hand, if a learner struggles with a free speaking task, more support may be needed to reduce overload and make successful performance possible.

The key point is not that learners need less information in every case, but that they need the right amount of information at the right time. Good instructional design reduces unnecessary load, supports learners when support is needed, and removes redundant help when it no longer serves a purpose. In that sense, effective teaching does not simply add more material. It should create the conditions in which working memory can be used efficiently for learning.


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