Type I and Type II errors

Question 1

how to control type I error

Answer 1

we control type one error when we choose the signifcance level

Question 1

What is a type one error

Answer 1

Rejecting the null when it is true, this occurs when p<signficance level but the null is remains true. This can occur bc in a 95% confidance interval we are 95% sure that our value will fall within that interval however there is a 5% chance that the value falls outside of this value

Question 2

What is type II error

Answer 2

Fail to reject the null when it is false , This may occur as there are times when the null is false however we do not have the evidance to spport it

Question 3

what causes type II error

Answer 3

our sample size and study design, a larger sample size should limit type II error

Question 4

what is POWER

Answer 4

1-P(typeII error) High powers make it easier to reject a null, low powers make it more challnaging

Question 5

mutplie comparisons

Answer 5

Suppose the null is true. We still have a 5% chance of rejecting a true null, and therefore a 95% chance of correctly not rejecting it.
If we have two nulls, both of which are true, then the probability that we correctly don’t reject either is 0.95*0.95 = 0.9025. This means we have a 9.75% chance of rejecting at least one of them, even though they’re both true.
The multiple comparisons problem states that, when we check a lot of p-values, the Type 1 Error increases.