Deciding with Personal Knowledge

by Christine Drew and Richard Erdmann

People make decisions based on what they know. Well, that makes perfectly good sense, right? There’s a name for using what you know to make a decision. It is called the availability heuristic. It is quicker and easier to decide based on what you know than it is to learn something new. It is a shortcut and it often works, which is why it is a heuristic. It is a shortcut that works, except when the knowledge is wrong or incomplete. 

We have a strong interest in this particular heuristic because our work is moving the learning sciences into learning applications. The problem? This knowledge bank, the science of learning, is not available in the professional ranks of teaching. For the most part, it’s not taught in colleges of education. Let’s look at some examples of what would be available knowledge in a complete bank about learning.

The following people are famous and important in learning science circles. How many did you study? Why are they famous?

Hermann Ebbinghaus
Eric Kandel
Edward Deci
F. C. Barlett
Donald Hebb
Robert Bjork

Hermann Ebbinghaus provides examples of why what we don’t know can hurt us. Memory, a book by Hermann Ebbinghaus, was published in 1885. This summarizes a few of the conjectures from his experiments. 

  1. There is a learning curve. The greatest learning gains are at the beginning, which makes sense. The learner is growing from an incredibly small base, so the initial learning gains are big. The smallest gains are near the end, when the lesson is near completion. 
  2. Now comes the one he is best known for – there is a forgetting curve. Our default setting is to forget what we learned and forgetting starts almost immediately. A teacher should always assume that the student forgets what is taught unless there is an intentional and well designed intervention.
  3. Remembering is fragile. It is a ‘use it or lose it’ proposition. If we want to remember what we learned, we need to repeat what we want to remember but massing the practice (like almost all teachers do on the day of initial instruction) is like cramming. It has a short term benefit but not a long term one. To have a long term benefit, the memory retrieval and application needs to be spaced daily over three or four days and then again and again over time – maybe spaced by a month or two. If all teachers did this, test prep at the end of the year would not be necessary. It is called spaced repetition or practice. It is so important that it should be in every pacing guide. Is it?
  4. You can learn faster with association and remember more. Association is a complex activity. The brain does it automatically but a good learner or teacher requires and guides it.
  5. Memory is more or less stable – permanent. It resides in the brain somewhere, even if you cannot retrieve it. As a result, relearning takes less time than initial learning and associations are used when learning, even unconsciously. 

Remembering is foundational. Learning is inferred from what a learner recalls and how the learner is able to use it. Knowledge is based on remembering. As a result, this is pretty important stuff not to know. If we were to pick up a pacing guide we would expect to see spaced memory retrieval. We don’t. If we were to analyze test preparation, we would not see it at the end of the year but spaced throughout the year, but we don’t. If you think that this has changed, read the following article,

Let’s go back to our examples of Covid-19 and in education, testing. The initial interpretation of Covid-19 was dependent on which knowledge bank you brought to the table. If it was last year’s flu, Covid-19 would pass. If it was the pandemic of 1918, Covid-19 would require social distancing to stop the spread. The knowledge bank at the table meant everything. Once it was accepted as a pandemic, the public had to hear the message over, and over, and over again before accepting it. Think of that as repetition.

If memory retrieval is essential to building a knowledge platform, isn’t questioning essential? Isn’t testing a form of questioning? Doesn’t questioning drive inquiry – curiosity? Couldn’t the right design of testing actually create interest? Bringing a memory bank to the table about testing that depends primarily on opinions about the end-of-year test creates a false mental framework.

All individual knowledge banks are incomplete. The question is how do you compensate? Adam Grant, author of Give and Take and Originals, has challenge friends. These are people who bring a different perspective to the work he is doing and they push back. You can hear the pushback in some of his podcasts, Work Life. Who are your challenge friends? Do you listen to them? They should be part of your decision-making tool kit. We explore what a decision-making tool kit might look like in later blogs in this series on Why Is Change Hard?