Type 1 and Type 2 error

Type 1 error (alpha) = Stating that there is an effect or difference when none exists. Mistakenly accept the experimental hypothesis and you reject the Null hypothesis. 

Type 2 error (beta) = Stating that there is not an effect or difference when one does exist. You fail to reject the null hypothesis.

Ok I hate this crap. You read it 10 times and you are still confused! So I came up with a better way to remember these errors. When I think of the numbers 1 and 2 I think of going to the bathroom, Number 1 being urination and number 2 = going poo. Let's start with number 2.

Gamble and lose = this is when you think you have to fart and only fart so you let it go and to your surprise it was more than a fart, it was a fart with some fecal matter also known as a "shart". This is a Type 2 error = You did not think there was anything there but you were wrong there was fecal matter there = Type 2 error = mistakenly saying nothing is there when in fact something is there.

Now for number 1 or urinating. Older men and people with UTI's or bladder infections often experience something called urgency which is the feeling that they have to urinate. So they head to the bathroom to let it flow only to find out there is no urine to flow. So they thought something was there but nothing was really there. This is a type 1 error = think something is there when there really is nothing there. 

Null hypothesis = hypothesis of no difference. You do a study on men and women and their sleeping patterns. The null hypothesis would say that you do not think there will be any difference between the men or women's sleeping patterns. The alternative hypothesis is the hypothesis of difference so the alternative hypothesis would state that there will be a difference in the sleep patterns of men vs women. 

So let's say you do the study and you fall asleep so you miss a big portion of tracking the data. So your results show that there is no difference in the sleep patterns of men and women but had you been awake to record the data properly you would have seen that the women slept much more peacefully and did in fact have a different sleeping pattern than the men. The error here is you are stating that something (differences in sleep patterns) is not  there  when in fact there really is something (differences in sleep patterns) there. Now think of the Shart you are saying nothing is there but in fact there really is something there. You go to just fart but accidently crap your pants! This deals with feces = Type 2 error. I think you got it!