👋 Hey {{first name | DistillED reader!}}

In this fifth edition of the CLT series, we're exploring transient information and why it causes students to forget your instructions before you’ve even finished giving them.

Transient information is information that disappears before students have finished processing it. The most common example is speech: once we’ve said something, it's instantly gone, unless students hold it in their working memory. Videos, animations, PowerPoint slides that move on and board work that gets rubbed are all fleeting and work in the same way (Wong et al., 2012).

In everyday life, this rarely presents a problem. We follow conversations, stories and films with relative ease. In the classroom, however, it becomes more challenging because students must hold earlier information in mind to make sense of what comes next.

John Sweller and Wayne Leahy give a neat example from a lesson on reading temperature graphs (Leahy & Sweller, 2011). Students can easily hold the spoken instruction “Find 35°C on the temperature axis" while looking at the graph. They can do the same with "Follow across to a dot". Join them into one spoken sentence and it gets much harder. Written down, students can read the first half, find it on the graph, then come back for the second.

What counts as "long" depends on how many ideas interact and what students already know. That makes this a close cousin of 👉 Element Interactivity.

In typical DistillED fashion, here's what transient information is, and what it isn't:

One study shows the transient information problem clearly. Year 6 students learned to read temperature graphs from a slideshow, with the explanations either spoken or written beside the graph (Wong et al., 2012). When the explanations came in short statements, the spoken version won. When the same content came in long statements, the result flipped: students who read it scored 43%, and students who heard it scored 23%. The content was identical, it was only the length that changed.

A second study took the diagram away altogether. Year 10 students learned how a bill becomes law, either by reading a two-minute explanation or by listening to it (Singh, Marcus & Ayres, 2012). Readers outperformed listeners on both the test and a harder transfer task. But when the spoken version was split into eight short chunks, with a five-second pause after each, listeners improved on both.

There was an interesting twist, too. In the first round of the study, readers performed only slightly better than listeners. The researchers noticed why: readers weren’t going back to re-read the text. In other words, having information available is only useful if students actually make use of it.

Videos follow a similar pattern. When Year 5 students learned to make an origami model, short video clips were more effective than still pictures. However, when the same demonstration was presented as one continuous video, that advantage disappeared (Wong et al., 2012).

There is an important caveat here. These studies used recorded narration and slides that advanced automatically, rather than live teachers in real classrooms. In our lessons, we can pause, repeat information and check for understanding. Nevertheless, the underlying principle remains relevant. When students need to hold several pieces of information in mind at once, anything we communicate only verbally places additional demands on their limited working memory.

Oliver Caviglioli offers a useful way of thinking about this: the board, the slide or the page in front of students can act as an external memory field. Information displayed there remains available, so students don’t have to hold it all in their working memory. This reduces the burden of holding information, without removing the need to think about it. This also fits with last week's edition. Cutting the repeat still applies: if students need to read something long, let them read it first, then talk.

👉 Students still do the hard thinking: The Generation Effect

👉 Read more on cutting unnecessary information here: The Redundancy Effect

The good news is that most of the fixes are easy. The five steps below all do the same thing: they make the important things stay where students can see them.

Consider how this might look at the start of a science practical. In a typical lesson, the teacher explains six steps aloud, students nod along, and the equipment comes out. By step four, some students are already asking what they were supposed to do first!

Now imagine a different approach with transient information in mind. Before the lesson begins, the six steps are numbered on the board. The teacher talks through each one, pointing to it as they go, before modelling the first step with the equipment. The instructions remain up and visible throughout the practical, giving students something to refer back to whenever they need it.

👉 Read more on modelling a process step by step here: Worked Examples

Working memory is limited, and information presented only through speech can quickly disappear before students have had time to make sense of it. By keeping instructions, key ideas and explanations visible in our extended memory field, we reduce the burden of holding information in mind and free up more capacity for thinking.

— Jamie

If you want more:

👉 Read Element Interactivity: why complex content is where transience hurts most

👉 Read The Redundancy Effect: when to cut, and why to read first and talk second

👉 Read Worked Examples: modelling processes students can follow step by step

👉 Read Cognitive Load Theory: the first edition in this series, and the big picture

👉 Get the Reducing Cognitive Load pack: practical ways to cut unnecessary load from your resources

👉 Get the Explanation and Clarity CPD Collection: for explaining clearly, with words and visuals working together

👉 Get the Memory and Cognitive Load CPD Collection: the fuller case for how working memory shapes learning

Cognitive Load Theory Unpacked One-Page Guide
To help you put this into practice, download Cognitive Load Theory Unpacked: a one-page guide to six strategies for managing what students must hold in mind, from checking prior knowledge to fading guidance as knowledge grows. Useful for your own planning, in coaching conversations, or during team PD.