Cognitive Load Theory Just KILLED Active Recall

If you think memorizing facts with active recall and spacing works best for learning then you're probably wrong and I'm going to explain why.

So if you search YouTube for evidence-based study techniques you'll be presented with loads and loads of videos on active recall and spaced repetition from students and experts and it makes it seem as though these are the only learning techniques that you need and if you use them you'll definitely ace your exams or learn effectively. The problem is that the sheer volume of videos and opinions means it can be super confusing to actually know how to apply these learning techniques to your own studies and to actually understand when to use them.

So before we understand why active recall and spaced repetition don't always work as well as people hype them up to we need to understand a little bit about how learning actually works in the first place, then we're going to look at something called cognitive load theory and then we're going to look at where active recall and spacing actually fit in to give you the results you want with some practical tips at the end focusing on how to apply these strategies to get the best grades and spend less time working.

Learn How To Learn
Learn How To Learn helps your get top grades. While saving hours of studying every week.

A Quick Story About Learning

When I was at medical school I went on a bit of a learning journey from unconscious incompetence in first year where I'd just read, highlight and cram my learning to the point that I failed an exam to conscious competence where I was coming top in the year and spending minimal time actually in the library as I'd taught myself the science behind effective learning techniques.

But not all of my friends improved their learning ability and by the time I'd mastered how to learn efficiently using the techniques we'll discuss shortly many of them were still spending hours and hours in the library. I remember one of my friends would use active recall with flashcards and try to use spacing because he'd watched a YouTube video or something similar but he was still spending like 12-hours straight in the library trying to memorize everything in the medical textbook. At exam time he was super strung out and looked terrible because he'd been studying so hard and then because he didn't do as well as he thought he might despite using these hyped-up techniques he asked me how I studied as he knew I didn't really go to the library that much. When he told me his interpretation of how to use active recall it kind of clicked for me that lots of people don't actually understand how to apply active recall and how it fits into learning. Active recall is proven by science to be better than simply reading or highlighting but if you're just memorizing an entire textbook that's completely wrong and this is potentiated by people on YouTube jumping onto trending terms without really knowing themselves.

So a bit like evolving from being a caveperson our understanding of how to learn effectively has to go on a bit of a journey and the reason I say that is because if you're watching this video and you're currently reading your notes or highlighting things passively then active recall and spacing are a great place to start but to understand how to use them to learn effectively let's simplify things and look at what learning actually means and how our brains learn anything in the first place.

Learning vs Studying Vs Memory

So let's start with the difference between the terms learning, studying and memory. The first thing I want to point out is that studying is not the same thing as learning and this may be something that is really obvious to you but I found that a lot of people haven't even thought about this and loads of YouTube videos kind of mix and match terminology. Studying is actually the physical process that we are doing; it could be the writing of notes when we're in class or revising material it could be us watching a video about something. Right now you might be studying this video as you're listening, it's the stuff we do out in the physical world and the purpose of doing this is so that we can produce learning and learning is actually the cognitive process that occurs and this is essentially when information is connected into our brain. We can say that we have learned successfully if that knowledge is retained in our memory and we can recall what we've learned and apply this knowledge. So studying causes learning which is the process that forms and allows us to recall from our brain's memory.

So now we've got that down let's look at how our brains actually form memories and the cognitive process of learning in a bit more detail.

How We Learn

Memory is the ability to take in information, store it, and recall it at a later time.

The concept of memory storage was analysed by American psychologists including George Miller in the 1950s, who developed something called Information Processing Theory which is a cognitive theory that focuses on how information is processed into our memory. The theory describes how our brains filter information, from what we’re paying attention to in the present moment, to what gets stored in our short-term or working memory and ultimately into our long-term memory.

The premise of Information Processing Theory is that creating a long-term memory is something that happens in stages; first we perceive something through our sensory memory, which is everything we can see, hear, feel or taste in a given moment. In order for a sensory input to enter our short-term memory we have to deem it relevant and this is where attention comes in we have to pay attention; our short-term memory is what we use to remember things for very short periods, like a phone number; and long-term memory is stored permanently in our brains.

Information Processing Theory Model

Miller suggested that human short-term memory can hold approximately seven chunks of information for around 5-15 seconds. More recent research has shown that this number is roughly accurate for college students recalling lists of digits, but memory span varies widely with populations tested and with material used.

Learn How To Learn
Learn How To Learn helps your get top grades. While saving hours of studying every week.

Rehearsal is the process in which information is kept in short-term memory by mentally repeating it. When the information is repeated each time, that information is re-entered into the short-term memory, thus keeping that information for another 5 to 15 seconds.
Now to keep things simple I'm going to consider the term working memory to be the same as short-term memory since it pretty much is but I'll be diving into how working memory functions as part of short-term memory in a future video so be sure to hit subscribe to hear about it first.

So now we've looked at how information gets into our short-term memory let's look at the key part for learning which is how we store things to our long-term memory. The process of transferring information from short-term to long-term memory involves encoding and consolidation of information. This is a function of time; the longer the memory stays in the short-term memory the more likely it is to be placed in the long-term memory. In this process, the meaningfulness or emotional content of an item may play a greater role in its retention in the long-term memory. Unlike sensory and short-term memory, long-term memory has a theoretically infinite capacity, and information can remain there indefinitely.

In educational psychology, memory creation is further broken into three stages: encoding, storage, and retrieval.


The Memory Process

  1. Encoding: is the process of receiving, processing, and combining information.
  2. Storage: is the creation of a permanent record of the encoded information.
  3. Retrieval (or recall): is the calling back of stored information in response to some cue for use in a process or activity like in a test.

Now as we know from the work of Hermann Ebbinghaus and his forgetting curve our memories and what we've learned gradually deteriorate with time and he showed that active recall and spaced repetition reduce the effects of memory deterioration but that's just a small portion of the picture since retrieval is also impacted by how the information is encoded.

The process of encoding a memory happens in our short-term or working memory and how well we encode information is dependent on a few factors and this is where cognitive load theory comes in and this is what I want to really focus down on since quality active recall and spacing are dependent on encoding which is all about our short-term memory which has a limited capacity and only receives sensory input that we pay attention to.

Cognitive Load Theory

Cognitive load theory looks at the way that we consider short-term memory while learning complex concepts or solving problems. And to explain it let's use a worked example going through the steps of memory we've just covered.

When you see something hear something or take in any type of information through your senses it enters what psychologists call sensory memory and from here your brain quickly filters out information that is irrelevant. Let's take the example of me being intentionally lazy and devoting my focus to a video game for example. The sound outside or the smell of food cooking in the kitchen is forgotten the information that is relevant goes into my working memory as my attention is on playing a game like Elden Ring or Zelda. Now once the information is moved to your working memory your brain begins to process it or decides to forget it and the ultimate goal is to store the important information into your long-term memory. Psychologists believe that within long-term memory are structures of information hierarchies called schema and they help you relate new pieces of information to existing pieces of information. Within the schema of my video game for example I may have information about what each button on my PS5 controller does or the backstory of a specific character, both of which are pretty hard to follow in Elden Ring actually. Now the first time I used my controller or played a game information about what each button does was in my short-term memory I rehearsed by playing and worked with the information long enough that it's now in my long-term memory. It's then easy to retrieve every time you pick up the controller. But not all information that's important ends up going from your short-term memory to your long-term memory so why is that? Well in some cases it's because you're overwhelming your short-term memory and this is exactly what cognitive load theory is all about. So long term memory is like a computer with unlimited data storage while short-term on the other hand can only process a few pieces of information at a time. If we fail to come back to the information in our shorter-term memory it'll be forgotten forever. Cognitive load theory suggests that if we want to learn more effectively we must keep this limit in mind and only load up a few pieces of information into our short-term memory at a time. If we overload our short term memory we will be more likely to forget and won't connect information that we're trying to learn and this is why people who spend ages in the library even if they are using active recall probably aren't learning as efficiently as they could be. Now our age and our development influence how much of a cognitive load an individual can take on at once but in general the simpler the information is the easier it will be to process and store in long-term memory. John Sweller the creator of the cognitive load theory also did a lot of work to describe the different types of cognitive load and how learners and teachers can construct learning materials and lessons to lighten the load and help people to learn more effectively.

So now we know some basics about cognitive load let's dive a little deeper into the three different types of cognitive load; intrinsic, extraneous and germane with some examples of each and look at how we can optimise each when learning to learn more effectively than pretty much anyone else.

Intrinsic Cognitive Load

Intrinsic cognitive load just means the burden imposed on short-term memory by the difficulty of the material. In other words, simple topics require very little processing capacity in short term memory, and complex topics demand a large amount of space. For example the theory of cognitive load has a little bit more of an intrinsic cognitive load than say a mathematical fact like 4 times 4 equals 16. Now when learning we can't really impact how complex a topic is but we can chunk information up and start with the simplest elements first to speed up how our brains process the information - remember small chunks are good for our short term memory with limited capacity.

When learning a language, you first learn the alphabet and then proceed to learn simple words or phrases—not complex prose. But you're not proficient in a language unless one can understand its complex prose. This is an example of something called element interactivity which basically means the complexity of what we're learning due to the levels of connectedness that depend on the type of information and the learners’ prior knowledge. It stems from the number of elements that must be simultaneously processed in working memory. In our language example because understanding prose depends upon not only understanding its nouns, verbs, adverbs, etc., but also how each of them modifies or alters the meaning of other words nearby this is element interactivity. So we want to minimize intrinsic cognitive load by simplifying complex topics into bite-size chunks and building up complexity. And this is another example of how if people using active recall are just memorizing facts and information that isn't directly relevant to building a deep understanding of complex topics they are probably not going to be able to then apply this knowledge because even though active recall is way better than just reading or highlighting, if you're not using active recall to actually test your application of the more complex topics you're not actually learning properly. For example if you only learn words but never practice actually putting together sentences you're never going to deeply learn a language.

Extraneous Cognitive Load

Next up we have something called extraneous cognitive load which is basically information not relevant to what you are learning and this is all about the method in which the information is taught and is really about limiting anything that isn't directly relevant to what you want to learn. So if you keep getting distracted by external information or the method of learning is ineffective this increases extraneous cognitive load and the goal of teachers, whether they know it or not, is to reduce extraneous cognitive load and communicate information in a simple and effective way.

When a learner's working memory becomes clogged up by unnecessary information, they may remember the irrelevant information and forget what they actually need to know. This is known as The Redundancy Effect and it often hinders learning due to inefficient use of short-term memory resources. For educators, this means reducing the unnecessary cognitive load of redundant information for learners and focusing primarily on what matters most.

Equally having to receive information alternatively from two or more sources can place a burden on short-term memory as focus is being spread too thinly and this is known as the Split Attention Effect. Switching between different sources can lead to learners remembering less content because their energy and resources are spent trying to process several things at the same time. Research from learning psychologists in Germany shows that people who learnt in a split-source format achieved lower learning outcomes than their peers who learnt in an integrated format.

As an example let's look at two ways you can learn a simple fact like remembering the Great Lakes in America. One way of learning these might be to use an acronym or mnemonic like HOMES where H is for Huron, O is for Ontario, M is for Michigan, E is for Erie and S is for Superior. A second method might be looking at a map and trying to learn that way. Obviously the first method is going to have a lot less cognitive load as it uses a mnemonic aid and it's easier to remember and the information is already organized for our brain as there's structure using the word HOMES and people who learn this will commit it to long-term memory faster as it has a lower extraneous cognitive load ie you're not distracted by all the other information on the map. So basically anything irrelevant to what you are learning needs to go and this is why it's so important that before you just start going through a textbook, video or lectures from A-Z using active recall you actually spend time understanding what the core concepts are, what is likely to be used regularly or tested and what just isn't that important. We want to reduce extraneous cognitive load as this will keep you efficient when learning, save time encoding and ensure active recall is focused on learning what matters rather than clogging your brain up with stuff that isn't relevant.

Germane Cognitive Load

Now the third type of cognitive load is germane cognitive load and this type of load occurs when we are creating a new schema for this concept and how we relate it to existing knowledge. Schema are structures in which we organize and hold information they provide context and make new information related to those schemas easier to remember. So let's say you enter an operating theatre with no prior knowledge of surgery. One surgeon starts the operation by asking you for your current level of understanding, introducing to you all the surgical instruments, who everyone is, what you can touch and what you can't and the reason for the operation. Now let's take another surgeon who dives into the same operation asking you to grab instruments that you're unfamiliar with and talking about new concepts. That the second surgeon is increasing your cognitive load as you've got to play catch-up as you attempt to build a more complicated schema with information that you do not already have in your long-term memory and it's putting pressure on you and just basically overloading your brain. We want to maximise schema creation and linking new information to existing concepts to help our brains encode efficiently and to also then become more adept at recalling this information from these schema. So again if you're not spending time to organize what you are learning and just memorizing facts from book chapters you're going to overload your brain and 12 hours in the library won't be producing quality learning that you can recall easily.

So now we've look at just why cognitive load kills the hype of active recall and spacing when you understand the science let's look at how to optimize our cognitive load and encode efficiently so that when we do use active recall and spacing to make learning stick we are doing it as efficiently and effectively as possible.

How To Optimize Cognitive Load and Encode Efficiently

So our main goal is to simplify the difficulty of the information, reduce irrelevant information and maximise how we organise new content and link it to what we already know to encode and the goal here is to select processing strategies that will increase the likelihood of a learner recalling new information at a later point in time. So here are 5 strategies I use to make sure I'm actually understanding what I'm learning and encoding efficiently.

Activate Prior Knowledge

One of the most important cognitive principles is the importance of relating information from long-term memory to information newly entering the system. If you are starting a study session going over existing knowledge at the start through self-testing is a must for reminding you where new content will fit in. For teachers and trainers any good lesson-plan begins the class with some form of prior-knowledge activation. It might be a reminder or a brief review of what was studied in the previous day’s lesson, or it could be a question similar to, “Have you ever had a problem you couldn’t solve?” The purpose of this phase of the lesson is to activate prior knowledge–i.e., bring long-term memories back into short-term memory so that new knowledge can be connected with old with the result of more solid understanding of the new information.


Skim reading through a new topic, reading the course curriculum and grouping together new information will help organize things in a meaningful way. In simple terms just organizing where your notes or active recall questions are stored on your computer or organizing study sessions by topics in your calendar are ways you probably naturally organize things without consciously knowing spending time organizing is actually really, really vital. And this also works as a basic memory strategy in everyday life — think about your latest visit to the shops with a shopping list, rather than using a random list try grouping items together like by meal or things like vegetables and then link this to the aisles in the shops as a mental cue to aid you.

Deep Processing

It is easy to become convinced that you spend all day everyday studying for an exam, then you'll ace the exam. However, cognitive studies show that it is not specifically the time you spend studying that matters most but how you actually spend that study time.

For example, jumping back to my friend at medical school, his exam-preparation strategy was using flashcards for active recall. He'd take terms from the textbook or lectures, write them down on flashcards, and then rehearse them until he had the flashcards memorized. He was convinced he knew loads but the problem with this approach to learning is that he had only done “surface-level processing” of the material, rather than “deep” processing. It is surface-level because he'd memorized terms and definitions rather than truly understanding the meaning and applications of those concepts so when he needed to apply that knowledge he just couldn't do it.

Deep processing occurs when we use something called elaborative rehearsal to connect a concept to other concepts that are already known or are being learned. Basically rather than just rote learning flashcards it involves thinking about the meaning of the information you're learning and connecting it to other information already stored in memory. For example, I sometimes write a summary of a concept in my own words to check my comprehension, following the Feynman technique of being able to explain things in simple terms and relating it to my own experiences. Another approach to facilitate deep processing is to think of examples of the newly learned concepts from your own life or experiences. So in medicine you might think back to a clinical case you've seen if you are learning about a specific new sign or symptom.

The point is, learning that comes from surface-level processing is not durable. people don't remember the content of flashcards for very long after the exam. But spending the same amount of time (or even less time) meaningfully engaged with new content can result in learning that could last for a lifetime.

Distributed Practice

To be the most effective learner, you need to “space” or “distribute” your learning over a period of time. Attempting to cram a lot of learning into one or two concentrated study sessions rarely works as shown by Hermann Ebbinghaus' work on the forgetting curve and spaced repetition but even before we get to recalling information making sure that your learning sessions are broken down and you are staying focused and engaged is absolutely vital. Taking breaks and doing things like exercising and getting a good night's sleep rather than doing like my friend did and staying up all night to learn also helps to aid memory consolidation which is the biological process by which memories are created and are impacted by sleep and our general health.


Scaffolding impacts intrinsic cognitive load by gradually introducing your brain to more complex topics just like putting training wheels on a bike first. If you are starting off learning a complex topic your brain will benefit from scaffolding like using worked examples, when a problem has been solved and each step that leads to the solution has been thoroughly explained or in medicine or languages watching a video of an expert walking you through the steps to reduce your cognitive load and actually understand how knowledge comes together in the application. And that's true of learning how to learn too so don't worry I'll be doing some screenshare going through in detail how I apply all of these concepts myself.

Once you've mastered worked examples we want to follow our earlier advice on chunking up intrinsic load and introducing more complexity. Doing things like completion tasks where some of the problem is shown but you need to apply basic knowledge are similar to the worked examples but are only completed partially and you need to finish the rest. This provides you with some structure so you don't get overloaded, but still stretches you. Once these are mastered you then can go crazy on complex active recall questions that apply knowledge and you need to solve problems independently.

For me when I skim through a lecture, video or textbook or question bank I'll look for worked examples and then ensure the active recall questions I'm creating actually test my understanding.

The Modality Effect

The final tip here to optimize cognitive load and encoding is all about understanding that the mind processes visual and auditory information separately. Auditory items in your short-term memory do not compete with visual items in the same way that two visual items, for example a picture and some text, compete with one another. This is known as the "Modality Effect." So, for example, explanatory information has less impact on working memory if it is narrated, rather than added to an already complex diagram. So you can mix these up and integrated audio and visual learning without overloading your brain.

And so to wrap things up and summarize we can only process so much information at once and if you jump in and start actively recalling flashcard facts you're going to overload your brain and you'll also miss out on actually understanding a topic and applying it your long-term memory. Active recall and spacing are awesome and way better than just reading things passively but too much information can lead to cognitive overload, which can affect the transfer to long-term memory. Reducing this when possible is important to maximise your learning efficiency and remembering the information for years to come.

Learn How To Learn
Learn How To Learn helps your get top grades. While saving hours of studying every week.