Perception vs. Reality: Discrepant Events How People Learn - Discrepant Events

When you look at the full Moon, how big does it appear to be in the sky? If you were to stretch out your arm and pretend that you could pluck the Moon out of the sky, pinched between your thumb and index finger, in the same way that you could pluck a berry off of a bush, what would you learn?


Firstly, that you would have to close one of your eyes in order to “zero in” on “grabbing” the Moon. Secondly, your perspective of how big the Moon appears to be would undoubtedly change. In fact, you would see the Moon appear to shrink before your very eyes as your fingers reach up to pluck the Moon from the sky. And this will happen on any date and at any time that the Moon is visible from Earth. Don’t believe me? Try it! If you do, you will experience a discrepant event.


A discrepant event conflicts with everything you think you have learned from past experiences. It grabs and focuses your attention, arouses your curiosity, and sets the stage for learning to occur. And if you want to really blow your mind, purchase a Lifesaver candy and hold it up at arm’s length while looking at the Moon. [Yes, close one of your eyes.] You’ll see that the Moon will immediately “shrink” to fit inside the hole of the Lifesaver every time, with room to spare! [Note: The hole in a Lifesaver candy is only 7 millimeters across.]

So, what’s happening? It’s called “The Moon Illusion.” At some times, the Moon will appear to be larger in the sky than at other times. To make sense of this, some people believe that the Moon moves substantially closer to the Earth during those times. However, while it’s true that the Moon’s orbit is not perfectly circular, the difference in distance from the Earth is so small from our perspective on Earth that it doesn’t affect how large the Moon appears to be.


Also, many people think a “larger” Moon is due to some sort of magnification caused by the Earth’s atmosphere. But this is all strictly an optical illusion. In fact, the eye is tricked, as the brain compares and measures the size of the Moon against the size of nearby objects, such as buildings and trees. The Moon appears huge, especially when it’s near the horizon because your brain knows that the Moon is much, much larger than a tree…. So the brain, in fact, creates this optical illusion of a huge Moon. If you keep a Lifesaver nearby or in your pocket, you can test the Moon Illusion anytime the Moon is visible in the sky… or if you don’t have a Lifesaver, you can simply hold up your fingers to pluck the Moon from the sky and watch the Moon shrink.
 
So, what are the learning and teaching processes presented during this exploration of the Moon Illusion? The process of learning can start with a focus activity, spotlighting a discrepant event, to get the learner’s attention. How?

1. The participant is presented with a surprise which is not the conclusion of the learning moment, but rather the introduction to the learning moment;
2. A discrepant event is used which actually prepares the brain to want to learn more about the subject matter being introduced;
3. An attractive prop [such as a piece of candy!] can be used as a learning tool; and, yes,
4. These techniques work with all formal and informal subject matter.

An effective introductory focus encourages the participants to process and apply the information:

1. by testing the information themselves;
2. by sharing the information with others;
3. by pursuing more information on the subject matter; and
4. by applying that information to the real world.

Only once the application of information occurs can we say that the participant has truly learned.


So, for those of you who will share this discrepant event and focus activity with others: you will have learned about how the human brain perceives the size of the Moon. For those of you who will peer through the hole of a Lifesaver to “size up” your own brain’s perception of the Moon: you will have cemented this teachable moment into your memory banks.
 
Here are a couple of other effective examples of discrepant events:


Distinguishing Colors: Note: A variety of brightly colored paper works effectively for this discrepant event; I am showing the use of blue, orange, and yellow pieces of paper (below).

Look at each of the three colors of paper side-by-side. Then cut the papers so that you have a two quarter sheets of blue paper, two quarter sheets of yellow paper, and two sixth sheets of orange paper. Take one of each of the blue and the yellow quarter sheets of paper and cut them into approximately ¼ -inch strips. Then place the papers as shown below, by laying one orange paper on top of the yellow paper and the other orange paper on top of the blue paper. Next lay the cut strips of colored paper on top as shown below: (a) the blue strips of paper across the orange and yellow paper and (b) the yellow strips of paper across the orange and blue paper. Notice: Do the orange papers appear to be the same shade of orange as each other? What’s happening?!

Clearly, the orange-colored paper did not actually change its color, however, just as in the activity of the brain comparing the size of the Moon to nearby, familiar objects, here the brain is comparing the different colors to one another. And while in fact, these pieces of colored paper don’t change their actual color, they have the appearance of changing color.


A fascinating discrepant event can open the door to an intriguing discussion of how the brain interprets information supplied by our senses.

Submitted by Guest Author Janet Yamaguchi

Janet Yamaguchi’s background includes a Bachelor’s Degree in Biology from California State University, Fullerton and 36 years of teaching experience: four years as a high school science teacher; eight years with the Orange County Department of Education; and twenty-four years with Discovery Science Center/Discovery Cube as Vice President, Education.


While working for Discovery Cube, Ms. Yamaguchi served on several advisory boards, including the MacMillan, McGraw-Hill Textbook Publishing Company (2006-08); and wrote middle school science labs for Holt, McDougal Textbook Publishing Company (2009). She served on the Science Review Team and the Science Expert Panel for the California Department of Education (2011-2013) in order to modify and edit the nationally developed Next Generation Science Standards (NGSS) for the State of California and in 2014, she was appointed by the CA Department of Education to the 20-person Strategic Leadership Team that created the statewide plan for implementing the CA-NGSS.


Before retiring from the science center in 2017, Ms. Yamaguchi was awarded the 2017 National Science Teachers’ Association’s “Distinguished Informal Science Educator” Award.