Memory is more than Ebbinghaus

This blog is inspired by the #blimage blog series.

“Dante Alighieri01”. Licensed under Public Domain via Wikimedia Commons

In February my wife and I visited Florence in Italy. It’s an extraordinary place – go for the art, go for the leather shops, go for the food, but if you ever have the opportunity, just go.

Walking past the Uffizi we paused in front of a statue. Recognising it was Dante Alighieri, we fell into a collective fit of the giggles. Then we recited together:

Dante Alighieri
Seldom troubled a dairy.
He wrote the Inferno
On a bottle of Pernod.

It’s a Clerihew, named for its inventor Edward Clerihew Bentley. All Clerihews follow the same four-line format and contain some ridiculous biographical nonsense.

My father – who is fond of all forms of poetry – recited this Clerihew to me when I was a young teenager:

Sir Humphrey Davy
Abominated gravy.
He lived in the odium
Of having discovered sodium.

I heard this Clerihew once, and remembered it. In contrast I had to ask my dad several times who the author was before I could remember his name – Clerihew. The picture of Davy suffering at the hands of the mob for his science was at once ridiculous and vivid and formed a dramatic picture in my mind.

Years later, living in Turkey, I purchased The Complete Clerihews at a British Council library sale of excess stock. A quarter century later, it remains a treasured book, always guaranteed to produce a laugh with its combination of Clerihew’s text and illustrations.

It is from this book that I read Dante’s Clerihew. Again, it stuck at one reading – it was so deliciously absurd, how could it not? At some point in our near two decades of married life, I recited it to my wife who laughed, appreciating in particular the sly innuendo of ‘Never troubled a dairy’ and it stuck with her, too.

And so, a few years later, we found ourselves in Florence, laughing at poor Dante’s statue.

All this says something about memory. Two different people hear 15 words in a particular order and remember them perfectly at one sitting.


Unlike my memory of Sir Humphrey Davy’s, I have no strong mental image of the Dante Clerihew, so this isn’t about pictures. Its appeal is purely in the sheer delight in the words, the absurdity of the situation, the portrayal of Italy’s leading man of letters as a lush, the anachronism of the drink Pernod. Together those 15 words form a coherent whole that stuck a vibrant chord with my mind – and my wife’s – and stuck, seemingly forever.

Now contrast this with what is often repeated about what we know about the human memory from the experiments of Herman Ebbinghaus. The ‘Forgetting Curve’ has been a standard inclusion in L&D presentations for many years now (including my own):


The Forgetting Curve

The common interpretation of this curve is that memory automatically decays after we are exposed to something new, and it needs several repetitions to remember the new thing.

It’s actually more complex than that.

Remember how Ebbinghaus did his experiments – by reading new, nonsense syllables and attempting to remember them. All subsequent experiments to explore this phenomenon have taken the same approach. The syllable sets are carefully sifted before they are given to people to ensure that each individual non-word has no meaning.

This is entirely right, if you want to explore people’s memory properly, you can’t have some people better able to remember their syllables because the syllable (let’s say ‘BRIK’) sounds more familiar than another group’s syllable (say ‘ZIK’).

In memory experiments, the content you learn is meaningless.

But in real life, much of what we learn is not meaningless. When my father rattled off the Humphrey Davy Clerihew, I already knew who that famous scientist was; I knew he had discovered sodium, and I knew what odium meant. There was very little entirely new meaning that I had to take on board. Only the arrangement of the words was new. The Forgetting Curve did not apply.

Let me be clear here. I am not saying that the Forgetting Curve is wrong. Quite clearly it is right for a great deal of what we learn. In fact, the very word Clerihew required me to do some spaced learning (going back and asking my dad repeatedly what that bloke’s name was) until it stuck. Why? Because the word by itself had absolutely no meaning. There were no hooks in my mind ready for it to latch on to.

In contrast, when I read the Dante poem I knew all the words, and they made me laugh. If I had been asked to remember this, instead:

Dairy the Alighieri
Pernod troubled on he
a bottle Inferno
On wrote a Dante bottle of seldom

I would have once again required spaced learning – repeatedly testing myself until I got it right.

Not everyone is a fan of Clerihews. But everyone has a memory that is particularly attuned to learning some things very easily. For me, it’s song lyrics, the origins of words and useless facts like the speed of light in miles per second and the capital of Mongolia.

In addition to these idiosyncratic traits, people develop the ability to memorize certain things faster and more accurately as a result of their work. Famously, Chase and Simon (1973) showed board positions from chess games to a range of players from beginners to international masters for about 5 seconds. When asked to recall the location of the chess pieces, the beginners could manage on average 4 pieces, while the masters could recall virtually all 20 pieces.

This was not a matter of super memory but of meaning. When shown a board not from a game, but with randomly arranged pieces, the masters fared no better than the beginners. They were unable to use their immediate appreciation of how the pieces related to each other to make sense of the position. It was like trying to memorize a poem with jumbled up words.

This knowledge can be used in learning and is. Sometimes spaced learning is the right choice. Sometimes it is the only choice. Sometimes we make content vivid, we use humour, contrast and absurdity to make it need less repetition. But as well as these tricks of the trade, the best content designers do something else.

They go to where the person already is, and use what they already have, to make the content coherent, resonant and easy to remember. They present their chess players with a real game position; they give their poetry lovers words with rich meaning, because they know the best language – the only effective language – is the language of your audience.


If you’d like to know more about spaced learning, read Dr Will Thalheimer’s excellent research piece.

If you’d like to take up the #blimage challenge, pick one of these photos and see what it triggers in your mind:

2015-05-12 15.15.56


2015-04-30 16.47.40

2015-06-03 13.52.51

5 responses to “Memory is more than Ebbinghaus

  1. I’ve been chuckling away this morning to another favourite Clerihew, which I just had to share with you:

    Cecil B de Mille,
    Rather against his will,
    Was persuaded to leave Moses
    Out of the Wars of the Roses.

    • Excellent piece Nick – I particularly liked the phrase ‘cognitive misers’. Shame it took me 5 years to catch up with you! (Although to be fair, I’ve had this piece in the back of my mind for a bit…..)

  2. Pingback: always something to learn

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