20 Assumptions

Assumptions Are Key

You've probably been warned more than once in your life not to make assumptions. This advice is far from accurate; it's necessary to make assumptions. You can't come to a conclusion about anything without making assumptions.

An assumption is a thought you have and presume to be correct. Based on that, you can come to a conclusion. The big difference between automatic versus critical thinking is:

• In automatic mode, you take it for granted your assumptions are correct.
• In critical thinking mode, you ask, “How do I know my assumption is a good one?”

The advice about assumptions should be, “Don't make assumptions without knowing how you arrived there or make assumptions you cannot validate.”

Have you ever left for work earlier than usual because the weather was bad and because you had to be there by a certain time? You assumed it would take longer to get to work because it was raining, snowing, or hailing. Why did you assume that? Because you've dealt with the situation before, and just about every time the weather is bad, the commute is slower. Therefore, your assumption is probably valid.

Let's say you're working on a project, and one team member you've never met is late to a status meeting. There is another status meeting one week later. Do you assume this member will be late? Because you've had only one experience with him or her, making that assumption would be a poor choice. However, if he or she were late to four out of the last five status meetings, then it would be a fair assumption to make.

Assumptions are formed from facts, observations, and experiences. You make an assumption about what might occur or what the current situation is. For example:

• It's 8:00 AM on Saturday morning. Your child has a soccer game scheduled at 2:00 PM (observation: although it's a fact that it is scheduled, there is no guarantee that it will actually occur). You hear the weather report: 90 percent chance of rain, starting at 11:00 AM and continuing through the rest of the day (observation). For the last three years, your kid's soccer game was cancelled when it rained (experience). Therefore, based on the starting time of the game (observation), the rain forecast (observation), and cancelled games because of rain (experience), you make the assumption this afternoon's soccer game will be cancelled.
• The last 10 times you had a conversation with your manager, you got more work to do (experience). You're in a situation where you need to have a conversation with your manager. You might rightly assume if you have this conversation with your manager, you'll probably get more work to do.
• A particular customer calls and places an order (fact). He cancelled the last six orders he placed (experience). You ask how firm the order is; he claims it's very firm (observation). You think to yourself, “That's what he said the last four times, and he still cancelled” (experience). Therefore, you figure you probably shouldn't count on this sale, because there's a good possibility he will cancel it (assumption).

You make thousands of assumptions each day, most of which you take for granted. When we drive our car to a store to buy something, we assume, among many other things:

1. We won't have a flat tire.
2. The car's gas gauge is correct.
3. The roads won't all be closed.
4. The store will be open.
5. We will be able to pay for the merchandise.
6. The store will have the merchandise.

We make a ton of assumptions, all based on facts, observations, and experiences.

Here is a more complicated example: You're attending a project status meeting to determine whether your group will complete this project on time. Most of the milestones look good and tasks are being accomplished, but a few are behind schedule. The people in charge of those deliverables say, “Yes, it's a yellow flag, but we think we'll be okay.” Two days later, the same tasks now have red status because they have fallen further behind. Again, people assure you that things will be all right. You've found while working with these folks that they tend to be optimists with good intentions and work really hard, but they miss milestones. Based on this experience, you make the assumption the group will not finish the project on time.

If you make assumptions based on facts that are not facts, on observations not indicative of a situation, or solely on a single experience, then your eventual assumption might not be a good one. You go into a store and see an item you recognize at a very low price. Would it be correct to assume that the prices for other items are low? Of course not, because it's only one experience, in essence, one item. However, if you examined 30 recognizable items, and almost all were at a lower price than the store from where you usually buy, you could assume the prices at this store are lower—at least on that day.

We make countless assumptions in automatic mode. But in critical thinking, we don't take our assumptions for granted. We ask what facts, observations, and experiences we are using to come up with these assumptions. Can we validate or invalidate these assumptions by gathering additional observations? Do others have different, contrary experiences?

People make different assumptions because they have different observations or experiences. If you listened to a weather report that said there might be rain (observation) but your friend heard a different weather report, then you might assume you need to bring an umbrella, but your friend would not.

Now it's time to put it all together. Facts, observations, experiences, beliefs, and assumptions comprise the premise. In the next chapter, we'll look at how these components are combined to form your solutions (conclusions) and how people combine them differently.