What does research say about memory?
Scientists and psychologists have spent years developing numerous models to try and unpack how our memory work. Whilst debates between them still continue, perhaps the most useful, for educators so far, is the multi-store model that includes the notion of short-term memory (STM), working memory (WM), and long-term memory (LTM). However, within academic literature the terms ‘STM’ and ‘WM’ have become problematic and require a little unpicking. Although some researchers use the terms interchangeably, others (for example, (Cowan, 2005)) suggest that the terms do actually differ. For Cowan, the STM is described as the temporary holding of new information, whereas the WM (although not a completely separate idea from the STM) is described as both the holding and active use of the new information. That said, Cowan (Cowan, 2005) also acknowledges that the difference between the two may just be a matter of semantics. Furthermore, Aben et al. state that ‘studies using correlational designs have not consistently succeeded to unequivocally differentiate between STM and WM’ (Aben et al., 2012). Given the sheer complexity and need for even more research in this area, this article, will use the term STM throughout and acknowledges the role of WM within it.
The differences between STM and LTM are essentially brought down to duration and capacity of storage. The STM has a limited duration and is thought to hold only a few ‘chunks’ of new information (for example, names, numbers, words, phrases, or other items) at a time. The exact number of items, though, has been debated for decades. Miller (Miller, 1956), for example, posited that the capacity of the STM was 7 +/- 2 items, whereas more recent research (Cowan, 2008) suggests that it is more like 4. This latter figure presents a potential problem for classroom-based learning. For example, English lessons that require students to know eight different rules about using commas, history lessons that involve learning long lists of dates and events, and maths lessons where students are engaged in learning complex formulae are possibly asking too much of their students’ STMs. What is likely to happen, therefore, is that due to cognitive overload within the lesson, students forget key parts of the new information taught from one lesson to another.
In a unit of work taught between September and October, for example, students may work through their learning intentions and probably do very well in the end of unit summative assessment. But are they going to score just a highly (if not better) in June when a lot more information on a variety of topics have been given? In the past, it was often believed that when information was stored into the LTM it was there for a lifetime. However, more recent research suggests that information in the LTM weakens after a period of time due to lack of recall (Sousa, 2015). To avoid forgetting, not only does research suggest that we need to introduce new information in small amounts, but also that it needs to be rehearsed to that it can be encoded into the LTM. In order to aid learning and to elicit whether our students have retained new information, a logical response might be to simply test them on a regular basis, and there is much evidence that retrieval practice is an effective approach. However, testing needs to be managed carefully or it can be problematic.
When students focus on the consequences of marks or grades, the emotional side of the brain takes over and the cognitive processing of new learning appears to decrease (Sousa, 2015). Furthermore, Gärtner et al., (Gärtner et al., 2014) have shown that elevated levels of cortisol have a negative effect on an individual’s learning, cognitive function and memory. Small amounts of cortisol are always present in the bloodstream and help the brain to stay alert and perform tasks. This ceases to be the case, however, when a student’s anxiety levels rise due to the knowledge that they are taking an important test (or assessment) which will result in some sort of mark or grade. What has been shown to happen, therefore, is that the increased anxiety levels cause the adrenal glands to pump more cortisol into the blood to warn the body it is stressed (Slavin, 1980). This also impacts on the STM, which, instead of focusing on responding to the test, shifts to calling on the LTM to help other areas of the brain deal with the stress the body is undergoing (Kim et al., 2010). As a result, frustration sets in and the student experiences difficulty in recalling information required from the already pre-occupied LTM. It is ironic, however, that the brain’s ability to remember emotional situations such as these is enhanced during periods of high cortisol levels (van Ast et al., 2013). For the student, this means that the next time they are faced with a similar situation, their emotional memory of the previously experienced stressful situation (and perhaps the low mark or grade as well) is recalled and cortisol levels rise again.
What can we do to enhance long-term learning in the classroom?
Making sense and making meaning
Sousa (Sousa, 2015) posits that if students are able to link new information with their own past experiences and knowledge of how the world works, they will be able to make sense of the new information given. Making meaning refers to whether the student sees the information as relevant to them. Hattie and Yates (Hattie and Yates, 2014) have suggested that if new information makes no sense or meaning, then it is highly unlikely that it will be remembered. This increases with one or the other being present, but if both are part of learning then the chances of getting new information to be encoded into a student’s LTM is very high – even after several months. For example, in maths, students who are working on ordering measurements could use results from a recent sports day event (which could be times or distances) to work out the results for their class in each event. Furthermore, in English, students could write a newspaper report to inform parents about the event.
Prior knowledge and organisation
In addition to making sense and meaning to the student’s own past experiences we must also consider their prior knowledge of learning. As Ausubel puts it:
if I had to reduce all of educational psychology into just one principle, I would say this “The most important single factor influencing learning is what the learner already knows. Ascertain this and teach [them] accordingly (Ausubel, 1968).
Hattie and Yates (Hattie and Yates, 2014) suggest that if students are not able to relate new information with their existing knowledge it will be quickly forgotten. With this in mind, what is also needed is to establish an organisational structure (also known as chunking) whenever we learn. This is an important aspect of retaining information in the LTM:
[w]e find it extremely difficult to learn random lists or when coping with unrelated materials. We need to find the organisation, structure and meaning in whatever we learn … We benefit enormously from being shown how to group information, how to locate patterns, how to use order, and how to schematise and summarise’ (Hattie and Yates, 2014).
If information is to stay in our memory then it has to be frequently rehearsed or patterns established to help aid learning and memorisation. The notion of rote learning, particularly with spellings or times tables, for example, may be a quick-fix solution, but retention using this type of learning has been found to be very low. Instead, mnemonics have been found to support ‘deeper memorisation’, as well as free up valuable space in the STM. For example, as an adult, even now, I still recall the mnemonic given to me by first music teacher who taught us that the five lines of the treble clef stave are: EGBDF by using ‘Every Great Band Deserves Fame’. Similarly, one of my primary school teachers showed us the spelling of ‘because’ with ‘Bake Easter Cakes And Use Six Eggs’. Later, my GCSE maths teacher helped us remember the formula for solving trigonometry problems with ‘Silly Old Harry’, ‘Caught Aunt Harriet’, ‘Treading On Arthur’ (SOH CAH TOA).
Forgetting is part of learning and memorisation
The science and psychology of memory on learning has implications on formative and summative notions of assessment. This is important because, even though teaching and learning may have moved forward, we need to find out what our students can still remember sometime after teaching. Whilst students may indeed forget parts of previously learnt material, providing them with opportunities for frequent rehearsal allows for greater depth of understanding as well as for both the STM and LTM to work together to help increase the speed of information retrieval for future use. From a summative perspective, for example, questions relating to previous topics or units of work could be included in current end-of-topic assessments. The active use of the information this elicits, then, has strong implications for formative assessment (Booth, 2017); we become clear as to where each student is in their overall learning so far, what still needs to be done, which then results in regular conversations as to how teaching and learning can move forward.
Enhancing memory through feedback
Whilst feedback is a key formative strategy for moving student learning forward, it is the quality of the feedback given which could have differing effects on pupils’ LTM. For example, feedback which identifies which answers are right and wrong may be helpful to students, but teachers who give hints as comments (Finn and Metcalf, 2010), such as ‘there are several errors here – find them, fix them’ allow students to go back and re-think, for themselves, the learning processes from the previous lesson. As such, this allows previous information to pass from the LTM to the STM, resulting in a quicker speed of retrieval for future use. In addition to this is the notion of delayed feedback; research studies (for example, (Mullet et al., 2014)) have shown that students retain more information in the long-term if feedback has been delayed a little. This is not to say that in-class immediate feedback should be disregarded; we know students like getting immediate feedback, and this is certainly important for maintaining motivation. What needs to be taken into account, perhaps, is whether the feedback we give would cause greater thinking if it has been delayed. This has implications on many assessment and feedback policies within schools. Referring to Bjork’s new theory of disuse, Wiliam suggests that ‘when students have to struggle in the learning task, the quality of their performance on this task reduces, but the amount of learning that takes place increases’ ((Wiliam, 2018), italics my own). Within this in mind, in order to help enhance long-term learning, what is required from teachers, though, is a careful balance between the two.
By understanding a little more of the science behind learning within the STM and LTM, we, as teachers, are able to create effective classroom learning experiences, which, with the regular interaction and interweaving of the key strategies explored above, are designed to limit cognitive overload and provide effective memory strategies to help aid the improvement of outcomes for all our students.