S2 help needed in hypothesis testing!

Hi... what's the definition of 'level of significance' in hypothesis testing and what's the difference between that and 'actual significance level'?
Pretty pretty please answer quick as I need instant help!

definitely very bad at stats but this is how I understand it

significance level
is the benchmark set
e.g H₀ is unlikely if the probability falls below a cetain level say 5%


actual significance is the probability of rejecting the H₀ incorrectly

PS I stand corrected

Ahhh.... ok... i understand actual level of significance but can you further explain level of significance a bit?? sorry for being a bother!!

Ahhh.... ok... i understand actual level of significance but can you further explain level of significance a bit?? sorry for being a bother!!

significance is the likelyhood(probability) of getting it wrong and reject H₀ when in fact H₀ is true

Yay!! Now i understand it! Thanks a bunch... I've got an S2 exam tomorrow and I've had difficulty understanding this!!

I think that the level of significance is what you're defining as 'very unlikely'.

If your significance level was 5%, then you'd reject $H_0$ if an event that had less than a 5% chance of occuring occured. You either have a type 1 error (don't worry about that in S2) or your model is not right.

You can't always have exactly 5% so you can choose values which are as close to that as possible, and the actual level of significance is the probablity of getting the values that would lead to you rejecting $H_0$.

good luck tomorrow