False  Positive and False Negative: Part II

Now you basically know what they are, but there's more to know.  So let's take it a step further and apply these two to the matter of reality.  When we try to see reality, we can see things correctly, or incorrectly.

In other words, what we see can be true, or false (for now, let's leave out the idea of intentional falsehood, or lying--what the boy who cried wolf did). 

We can't eliminate both false results at the same time

It would be nice if we could, but we can't.  n spite of all our efforts, we can come up with invalid, or false observations, or conclusions.  So we have to deal with that, too. 

BUT, and this is a big but, when we try to reduce the possibility of one kind of false conclusion, we increase the possibility of the other.   The more we try to prevent a false positive, the more we make it possible to come up with a false negative, and vice versa.

Why?  Because how deal with false positives and false negatives is by how high, or low we set the bar for deciding whether something is true, or not.   The "bar" is the criteria for deciding validity.

Here's how it works:

If we set the bar high for saying something is true, we increase the possibility of incorrectly saying something is false (a false negative). 

Take a murder trial, for example.  We set the bar high by telling the jury to convict a person only if the evidence is "beyond a reasonable doubt."  That means if we have some doubt, don't convict, and this is setting the bar for convicting someone pretty high. 

And that means, based on the evidence provided, we might have a "reasonable doubt" when the person is actually guilty--as a result, we come up with a "Not guilty" verdict.  Turns out this is a false negative, because the person is really guilty (but we couldn't be sure).  Since we've set the bar for conviction high, some people who are really guilty may go free. 

Most people would prefer this.  Why?  Because if we set the bar low in a murder trial and say go ahead and convict someone if we're only "pretty sure" the evidence shows that person to be guilty, we increase the chance of convicting an innocent person.   And we might end up executing, or permanently imprisoning someone who didn't commit murder.

Same thing with the medical diagnosis.  If we set the bar high for for saying there is NO illness, we increase the possibility of saying there is an illness when there isn't.   Most people would prefer this, because the alternative is failing to diagnose a real illness.

 If you'd like to know even more about this topic, including how it fits in the Scientific Method.

 To read about a couple ways of thinking (divergent and convergent)

 To read about causality

 To read about who likes it when people are ignorant, or stupid

 To go to the Articles Page.