You may be making inferences every day of your life and not even knowing that you are doing it. It is normal. Inferences are thought processes that are performed almost without realizing it and that they are based mainly on making conclusions about what is seen and what is reasoned. But how exactly does an inference work?
What is an inference
Inferences are conclusions reached on the basis of evidence and reasoning. Cognitive psychologists use computer models to draw conclusions (make inferences) regarding mental processes.
Inferences are missing pieces of information that an individual fills in through prior knowledge or through prior theories or beliefs. For example, if someone walks into a room and sees that digital clocks are flashing, you can "infer" that there must have been a recent power outage. Therefore, an inference is a process of drawing conclusions based on the evidence. On the basis of some evidence or a "premise," a conclusion is inferred. Examples:
- Premise: The news says there is a 90% chance of rain. It is inferred: It's a good idea to go out with an umbrella.
- Premise: My throat hurts and my nose is running. It is inferred: I may have caught a cold.
- Premise: Grapes are poisonous to all dogs. It is inferred: You better not give my dog grapes.
There are also bad inferences, or inferences that may appear persuasive that are misleading on subsequent inspections. For example:
- Premise: The news says there is a 90% chance of rain. You should not infer: There is a 10% chance that it won't rain. Why? With a 90% chance of rain, it is very possible that it will rain.
- Premise: My throat hurts and my nose is running. You must not infer: I must take antibiotics. Why? Antibiotics should only be used if you have a serious illness, and they usually don't work for colds anyway.
- Premise: Grapes are poisonous to all dogs. You must not infer: Dogs should not eat any fruit. Why? Apples and bananas can provide your dog with vital nutrition for your dog.
The strength of the argument depends entirely on two things: the accuracy of the evidence and the strength of the inferences. If you have strong evidence and draw valid inferences, your argument is complete.
Inference types
To better understand the inferences it is necessary to differentiate what types exist. There are two basic types of inference to understand:
Deduction or deductive inference
This type of inference is based on logical certainty and starts from a general principle and then infers something about specific cases. Example: 'Grapes are poisonous to all dogs. ' This allows you lower than poisonous ones for your dog.
If the premise is true then the conclusion must be true. There is no other possibility. However, keep in mind that this doesn't really tell you anything new: once you say 'grapes are poisonous to all dogs', you already know that grapes are poisonous to your particular dog. Deduction has the advantage of certainty, but it does not generate new knowledge.
Induction or inductive inference
This type of inference is a probability-based inference. Generally, you start with specific information and then infer the more general principle. Example: "For the last two years, Lucia has woken up at 8 in the morning every day." This allows you to infer that Lucia probably wakes up at morning today as well. You're probably right, and it's a reasonable inference, but it's not safe. Tomorrow could be the first day that Lucia decides to get some more sleep. Despite this uncertainty, however, Induction offers the ability to predict future events and create new insights.
Are inferences the same as observation?
An inference starts from a premise (like evidence) and then moves beyond it. But what happens when you only see the evidence for yourself? Do you need to make inferences then? It may seem that inference and observation are two very different processes, related, of course, but very different. But in fact, it is not so easy to separate them.
Example: 'I saw Luis go into the supermarket the other day.' This is a direct observation. It does not seem to imply any inference. But if you look carefully and skeptically, you will see that it contains many inferences: what do you really see? 'I saw someone who looked like Luis walk into the supermarket the other day.'
You may well have made a mistake! It's easy to confuse people on the street with the people you know, so you can't be completely sure you've seen what you think you saw. The person could even be any other person or that you get completely confused.
This isn't the kind of thing you really need to worry about - 99% of the time, you're right about what you're seeing. The point is that observations are never 100% reliable, and they always involve a certain amount of inference. This may sound like an abstract question - after all, we trust our senses in everyday life, and they generally work well. Shouldn't that be good enough to be able to argue truthfully?
Philosophical history of observation and inferences
There is a famous story in philosophy that begins that way:
A great philosopher was speaking in a room full of colleagues, trying to draw his conclusion in conversation and realize that observation is reliable enough for most practical purposes. To illustrate his point, he looked over it and said, 'Look, I see the window above me! I see the glass panels, and I see the blue sky through them! There is no need for me to be skeptical about things that I can see with my own eyes! ' But in fact, the window was a highly realistic painting.
The point is, don't rely too heavily on direct observation: your senses are not always reliable, and even when you think you are making direct observation, you are actually making inferences, which may or may not be correct.