Subject:  Metacognition – Copernicus’ Definition of True Knowledge

Event:  Birthday of Nicolaus Copernicus, 1473

Today is the birthday of Nicolaus Copernicus, a man who not only changed the world as we know it, but also the universe.  

Nicolaus Copernicus (Wikimedia Commons)

Born in Poland in 1473, Copernicus was both a polyglot and a polymath.  He spoke Latin, German, Polish, Greek, and Italian.  In addition to holding a doctorate in canon law, he was also a physician, mathematician, classics scholar, translator, governor, diplomat, and economist.  Today, we know him best as the astronomer who challenged the orthodox belief that Earth was the center of the universe.  Fifteen-hundred years after the ancient Greek astronomer Ptolemy established his theory that the planets, the sun, and the stars revolved around a stationary Earth, Copernicus presented his revolutionary theory.  He claimed that not only did the Earth rotate on its axis, but also that Earth and the other planets revolved around the sun.  Copernicus’ work in astronomy was the quintessential achievement of the Renaissance, totally transforming mankind’s view of the universe and paving the way for future work by Galileo, Kepler, and Newton.

A true man of science and of learning, Copernicus embodied the Renaissance ideals of searching for knowledge and challenging conventional wisdom. His opus On the Revolution of the Celestial Spheres was published in 1543, the same year he died (1).

One quotation that typifies Copernicus’ scientific approach is one that uses simple terms to express a profound insight:

To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.

Today cognitive psychologists sum up Copernicus’ insight using a single term: metacognitionMeta is Greek for “about,” and cognition is Latin for “to know.” Metacognition, therefore, is “thinking about thinking.”  More than just being aware that we think, metacognition is the process of monitoring our own thinking.

As Copernicus reminds us, metacognition is not just what we know, it is also being aware of what we don’t know, as well as being aware of the ways we sometimes delude ourselves.  To understand the ways we think best and the ways we fall short of sound thinking, we should always keep in mind the relationship between both knowledge and ignorance.  

Notice, for example, how the following wise voices from the past express this relationship:

-Real knowledge is to know the extent of one’s ignorance.  –Confucius

-The greatest obstacle to discovering the shape of the earth, the continents and the ocean was not ignorance but the illusion of knowledge. –Daniel J. Boorstin

-The only good is knowledge and the only evil is ignorance. — Socrates

-The recipe for perpetual ignorance is: Be satisfied with your opinions and content with your knowledge. — Elbert Hubbard

-To be conscious that you are ignorant is a great step to knowledge. — Benjamin Disraeli

-The beginning of knowledge is the discovery of something we do not understand. — Frank Herbert

In the book Make It Stick, the authors discuss one specific learning strategy that employs metacognition to help learners be more productive and more efficient in their study.  The strategy is called retrieval practice, and recent studies have documented that this strategy is much more effective than rereading a text, highlighting a text, or even reviewing notes.

The key aspect of retrieval practice is self-quizzing or testing.  When reading a text or listening to a lecture, therefore, the student should generate questions for self-testing.  Once the student has finished reading or listening, he or she should use the questions to recall and recite out loud the facts, concepts, or events from memory, without using the book or notes for reference.  The basic premise of retrieval practice is that learning that sticks is learning that is effortful.  Furthermore, the effortful act of retrieving knowledge from memory strengthens the memory, increasing the likelihood that knowledge will stay in long-term memory.  Like walking an unfamiliar path through the woods, the more you travel the path, the more confidence you have in remembering your way without getting lost.  Retrieval practice also decreases the likelihood that students will delude themselves into believing they know what they don’t know. Since the strategy requires that students recite answers aloud without notes, they are able to exercise good metacognition by clearly determining what they know and what they don’t quite know yet (2).

Recall, Retrieve, Recite, Ruminate, Reflect, Reason:  What is retrieval practice and how does it relate to metacognition?

Challenge – What Do You Know?

How can you apply retrieval practice to increase your metacognition?  Select an article or short story that you have not read before.  As you read the passage, write down three questions based on the key ideas you’re reading.  When you finish the reading, put the passage away, and attempt to answer each of your questions by reciting the answers out loud.  As you answer each question, rate your level of confidence with your answer on a scale of 1 to 10 (10 being you feel highly confident; 1 being you need to look back at the passage to answer).  Once you have finished, take a moment to reflect on the strategy.  How did it feel to answer out loud?  Do you feel like this strategy will work for you in the future? 


1-”Nicolaus Copernicus” – New Mexico Museum of Space History

2-Brown, Peter C., Henry L. Roediger III, Mark A. McDaniel.  Make It Stick:  The Science of Successful Learning.  Cambridge, Mass.:  Harvard University Press, 2014.


Subject:  Memory – Herman Ebbinghaus

Event: Birthday of John Medina, author of Brain Rules, 1956.

Today is the birthday of John Medina, a molecular biologist at the University of Washington School of Medicine.  In 2008, Medina published a book called Brain Rules where he summarized research on the human brain in twelve categories, including exercise, sleep, stress, attention, and memory.  In the book, Medina endeavored to focus on what is known about the brain based on research rather than to speculate on specific prescriptions or recommendations.  His standard was that supporting research for his brain rules must be supported by published, peer-reviewed, and replicated research.  

Hermann Ebbinghaus (Wikipedia)

In his chapter on memory, Medina presents a simple rule:  “Repeat to remember.”  To explain important insights on how the human brain transfers knowledge from short-term memory to long-term memory, Medina profiles a man we might call the ‘father of memory,’ the 19th-century German researcher Hermann Ebbinghaus. 

Ebbinghaus spent years memorizing three-letter nonsense words, such as TAZ, LEF, REN, and ZUG.  His purpose for doing this was to gather data on the lifespan of human memory.  What he found was that human memory is fleeting; without reinforcement, students forget about 90% of what they learn within 30 days.  The good news, however, is that Ebbinghaus also discovered the key to extending the lifespan of memories, which is repetition in timed intervals.  In other words, the effortful act of trying to retrieve a memory strengthens that memory and makes it more likely to survive in long term memory. Ebbinghaus also discovered a concept known as the serial position effect.  For example, if students are given a list of words to remember, most will remember the first few and the last few.  Words in the middle are most likely to be forgotten.  The name for our tendency to recall what is presented first is called the primacy effect.  The name for our tendency to recall what is presented last, or most recent, is called the recency effect.

Writers and speakers should consider the serial position effect when organizing their messages.  Your hello and your goodbye are always the most memorable.  Order matters.  Every piece of writing and every speech has a beginning, a middle, and an end.  Put important points at the beginning and the end.  And realize that you will need to put in extra effort if you want the middle of your message to be memorable.

As both Medina and Ebbinghaus remind us, when it comes to memory we must remember that like water in a glass it can evaporate quickly unless we actively do something to stop it from disappearing.  The keys to memory are spaced repetition coupled with retrieval practice — the practice of consciously recalling information without looking at notes.  If you want to move something from short term to long term memory, you must take the time to repeat it, recite it, and retrieve it using deliberately timed intervals.  While it is true that procrastination is the thief of time, it is also, clearly, the thief of memory (1).

Recall, Retrieve, Recite, Ruminate, Reflect, Reason:  What did Hermann Ebbinghaus discover about memory, and how can we apply his concepts for more effective learning?

Challenge – Recall, Recite, Repeat:  Apply Medina’s rule for memory and Ebbinghaus’ spaced repetition to commit a short poem of at least ten lines to memory.


1-Medina, John. Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School. Seattle, WA: Pear Press, 2008. ISBN 978-0979777707