The Mental Tool Rack: Scripts and Schemas

I was in the middle of writing the next great American novel when my hard-drive became extremely fragmented, and it mixed up all of my sentences. Can you help me put them back in order?

1. I cleaned up my mess and threw away my napkins, wrappers, and cup.
2. I waited for my food to be prepared.
3. I ate my delicious food.
4. I paid for my food.
5. I read the menu behind the cashier and decided what I wanted to order.
6. I sat down.
7. I placed my order.
8. I opened the door and walked into the restaurant. 
9. I left the restaurant.

How did you do? When you first started the task, was there any ambiguity that you had to resolve before putting the sentences in order? How did you decide where to put things in sequence? To see the order that I intended, check the footnotes [1].

"Line!" --Ned Nederlander in Three Amigos!

One of the emerging themes throughout this blog is that the mind craves (at least) two things: meaning and order. To make sense of the information-rich world, it helps when actions and events follow a pattern. Over many exposures to the same sequence of events, the mind assembles a script, that is, a mental representation of the expected sequence of events for that situation. You have many different scripts, like going to a restaurant, flying to another city, going to work/school, shopping for groceries, or attending a sporting event. Scripts help set expectations about what is supposed to happen, and they greatly decrease the amount of problem solving that you have to do. If you don't have a script for a given situation, then you find yourself trying to figure out what to do next. 

For example, when my wife and I bought our first car together, we went through a dealership. Neither of us had ever bought a car from a dealer, so we were pretty clueless about all the steps that stood between us and actually driving off the lot in our new (to us) car. We were particularly bewildered when, after we had test driven a couple cars and selected the one we wanted, the salesperson who had been helping us through the process had to go talk to his manager several times during the negotiation process. We now know that this was all part of a very typical script that takes place at most car dealerships: The customer looks around the showroom; a salesperson approaches the customer and tells him why the car he is interested in is ok, but why another model is even better; the customer takes the car(s) for a test drive; and then the customer, salesperson, and an unseen "manager" engage in a long and drawn out negotiation that, in stories with happy endings, results in the customer getting a reasonable deal on their car of choice.

A Schema Is Like an Organized Tool Rack

Scripts work well for organizing sequences of events. There is another mental representation, called a schema, that does essentially the same thing for information in general. In fact, you could say that a script is a type of schema that is specialized for one particular type of information (i.e., events). 

Traditionally, a schema is described as a structure with labeled slots. I think of it as a tool rack where all the tools have an outline drawn around where they should go. When an old tool is ready to be put away, you find the spot where it fits on the rack and store it there for future use. If an unfamiliar tool comes your way, you will likely look at your well-organized tool rack, see whether the new tool seems like any of the others you already have, and store it with those that are most similar to the new one. 

A good example of a mental schema comes from my hobby-level interest in cars. I love reading about the newest models and their embedded technologies. Over the years, I have built up a schema for cars. The slots in my schema include: category (e.g., sedan, coupe, sports car), make (e.g., Honda, Ford, Porsche), model (e.g., Civic, Taurus, 911), and origin (e.g., foreign or domestic).

Schemas can be violated when you encounter new information that doesn't fit into the existing organizational structure of the schema. When this happens, there are a couple of potential outcomes. One outcome is that you dismiss the new information because it does not fit into your current understanding of the world. Another outcome is that you misconstrue the true nature of the new information by trying to fit it into an existing schema where it doesn't really fit. Yet another outcome of a schema violation is that it inspires a person to modify his or her existing schema to accommodate the new information. I recently had my car schema violated when I learned about the Tesla Type S, which is a purely electric car. It has no tailpipe, spark plugs, or fuel door. In fact, it doesn't even require an oil change! To accommodate these new facts, I had to add a new slot to my car schema, which is fuel type (e.g., gas, pure electric, hybrid).

The STEM Connection

One could argue that the primary goal of education is to help students create accurate and detailed scripts and schemas. Because we live in a changing world, however, educators also need to confer upon their students the tools to notice violations and modify their representations when needed. 

The scientific method is perhaps one of the most successful scripts for producing new knowledge. A scientist starts with noticing something in the world that is in desperate need of an explanation. Toward that end, the scientist formulates a hypothesis and begins the arduous task of collecting data to confirm or disconfirm her hypothesis. This script works well, but it's important to teach budding scientists that they need to be willing (eager even!) to update their beliefs once the data are collected. This can be difficult, of course, but it is the best way to move the field forward. In a sense, scientists need to be flexible in constructing and updating their schemas. 

Some scientific discoveries, like penicillin, happen precisely because some piece of empirical evidence violated a scientist's schema. As the story goes, Alexander Fleming was working on a project that required him to create colonies of the Staphylococcus bacteria. Getting nowhere, he decided to take a vacation, and he left his lab in disarray. As expected, when he got back from vacation, some of his petri dishes were overrun with bacteria. What he didn't expect, however, was that some colonies were suspiciously missing. Fleming noticed that some of the bacteria were killed by a mold that was also growing in the dish. In that moment, Fleming experienced a profound schema violation.

Louis Pasteur famously said, "In the fields of observation, chance favors only the prepared mind." Given the language introduced here, we might recast Pasteur's recommendation to students to become more like Fleming: Take the time to construct a detailed schema. Then, be on the lookout for violations of your schema because they might result in important scientific advancements. 


Share and Enjoy! 

Dr. Bob

For More Information

[1] The answer is: 8, 5, 7, 4, 2, 6, 3, 1, 9

[2] Hollywood relies on schema violations to delight their audiences. The Matrix and Memento are excellent examples of movies that rely on violating our schemas to enhance the storytelling.