In 1980, K. Anders Ericsson and his colleagues published a fascinating experiment. They took a student of average intelligence, memory capacity, and IQ and had an experimenter test the limits of his memory.
The experimenter read a series of random numbers and then had the student recite them back in the exact order. If he was able to recite the numbers in the correct order, the experimenter would add another digit to the next random set. If he made a mistake, the next set of random numbers would be one digit shorter.
At the beginning of the experiment, the student proved his average intelligence and memory by only being able to memorize a sequence of about 7 numbers. This also confirmed George Miller’s earlier theory that an average human can only hold 7 items (+/- 2) in their working memory at a time.
The experiment was repeated, 4 days a week, for almost two years.
20 months later, the student who began with an average memory, just like you and me, could now memorize a sequence of numbers 80 digits long. Imagine 8 people telling you their phone number (including area code) and being able to recite it back perfectly all at once.
How did the student achieve such a dramatic increase in the ability of his short-term memory?
The answer to how the student's learning retention rates improved so significantly can be found by analyzing the concept of chunking.
What is chunking?
Chunking is the act of breaking a component into smaller “chunks” of related information. This very sentence you are reading is composed of individual letters that have been “chunked” together to form words and a sentence.
Every skill is composed of chunks that aggregate to form the greater whole. For example, if you want to learn how to swing a golf club, you need to learn several different things: how to grip the club, how to position your feet, the proper stance, how to bend your elbow in the backswing, how to follow through, where to focus your eyes during the swing, how to retrieve your golf ball from the woods, etc.
It would be impossible to learn everything at once since our working memory can only hold about seven items of information at a time. So, decompressing the skill into bite-sized chunks and mastering them one at a time until the act becomes unconscious is an effective way of learning.
How does chunking work?
"There are three straightforward sides to chunking processes—the search for chunks, the noticing and memorizing of those chunks, and the use of the chunks we’ve already built up. The main purpose of consciousness is to search for and discover these structured chunks of information within working memory, so that they can then be used efficiently and automatically, with minimal further input from consciousness." - Daniel Bor, The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning
In addition to reducing the cognitive load, chunking also provides meaning and context to the information, making it easier to remember.
How was the student in the experiment able to memorize 80 random numbers?
It turns out the student was a track runner. Instead of seeing a random strings of numbers, the student converted them to track times, with 8357 becoming 8 minutes and 35.7 seconds and so forth. After several months, he discovered a new strategy that further increased his ability to recall the numbers. As explained in The Ravenous Brain:
“…he was using his memory of well-known number sequences in athletics to prop up his working memory. This strategy worked very well, and he rapidly more than doubled his working memory capacity to nearly 20 digits. The next breakthrough some months later occurred when he realized he could combine each running time into a superstructure of 3 or 4 running times—and then group these superstructures together again.”
The student was combining 3 or 4 running times into a larger chunk. While he never held more than 7 items in his working memory at once, by chunking the numbers into larger groups, he was able to expand his ability to recall the numbers. Chunking allows us to “hack” the limits of our working memory by taking complex data, decompressing it, and then putting it back together in a way that is easier to understand.
Three Ways to Chunk
If you’ve ever wondered why phone and social security numbers include dashes, it’s because the dashes make the numbers easier to remember (for example, is it easier to memorize 6125559510 or 612-555-9510?). By separating the numbers into arbitrary groups, they are easier to recall.
"Spotting patterns is about finding redundancy in the information. You can compress the information into a different, smaller, and more useful form by spotting parts that repeat in some way or other, and, ideally, capturing the repetitions in a rule. If we can successfully turn any group of data into a pattern or rule, then near-magical results ensue. First, we no longer need to remember that mountain of data—we simply need to recall one simple law. But the benefits don’t just stretch to memory. We’re also, crucially, able to predict all future instances of this data, and so control our environment more efficiently. The rule may even capture something about the mechanism of the data, allowing us to understand it in a more fundamental way."
- Daniel Bor, The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning
It was once thought that master chess players had photographic memories that allowed them to easily recall strategies and improvise. The Dutch psychologist Adriaan Dingeman de Groot was skeptical of this theory so he conducted his own experiments with chess players. He discovered that what separates chess masters from novices isn’t photographic memory, but the knowledge and memorization of different patterns.
Organizing involves dividing a group into multiple categories based on meaning. For example, when learning a new language, one might choose to learn nouns before moving on to verbs, adjectives, and all of the different tenses.
Tips for Applying Chunking
1. Understand where the learner is coming from
Using chunking often involves understanding what the learner knows so you can determine how far to decompress the skill. If you break a skill into too small of chunks, much of the learning will be repetitive. If you don't break a skill into small enough chunks, the learner will be needlessly confused and frustrated. The extent to which you should decompress a chunk of information or skill is a balancing act that requires an assessment of the learner's knowledge so you don't repeat what they already know, but build on it.
2. Build each new chunk upon existing knowledge
Building upon what the learner already knows creates a far more efficient learning experience. By connecting new information to information the learner has already mastered, it shrinks the emotional learning barrier and shows the context of the new information. When you understand the context of information, it’s much easier to see how it is important as well as relates to the whole.
When we design and deliver blended learning solutions for clients, we often recommend doing eLearning before classroom training. This is an effective way to bring learners who may be at different levels to a common baseline of knowledge.
It’s helpful to think of learning a new skill much like putting together a puzzle. You have a model of what your goal looks like, but the only way to get there is by connecting one piece at a time. Sometimes you might be starting with a half-completed puzzle.
3. Focus on one thing at a time
New information needs to be learned slowly and in the context it will be used. When you speed through a course, you may get a good feeling from checking it off a list, but you won’t receive the lasting change of improved performance.
Focus the learning experience on one chunk at a time. If you are creating an eLearning course, this means only showing one main idea, or chunk, on each slide. Learning slowly so you can perform quickly seems strange, yet it’s exactly how many world-class performers learn.
Daniel Coyle, in his book The Talent Code, explains how experts approach chunking:
First, the participants look at the task as a whole— as one big chunk, the megacircuit. Second, they divide it into its smallest possible chunks. Third, they play with time, slowing the action down, then speeding it up, to learn its inner architecture.
4. Make time for practice
To really master a “chunk” of information, you need to shift from passive consumption of information over to active practice. The student in the experiment mentioned earlier was only able to develop an improved memory because of practice and repetition. Only through active practice and repetition can information shift from working memory to the unconscious, allowing the learner to advance to higher level thinking.