levels of significance and type 1/2 errors

Question 1

Why do we have to decide a level of significance we are happy with?

Answer 1

Statistical tests are not 100% accurate, there is always the possibility that the results obtained were due to a chance/fluke

Question 2

What are 3 significance levels?

Answer 2

p ≤ 0.10
p ≤ 0.05
p ≤ 0.01

Question 3

What is p ≤ 0.10?

Answer 3

There is a 10% probability that your results are due to chance. results can be accepted with a 90% confidence level.

Question 4

What is p ≤ 0.05?

Answer 4

There is a 5% probability that your results are due to chance. results can be accepted with a 95% confidence level.

Question 5

What is p ≤ 0.01?

Answer 5

There is a 1% probability that your results are due to chance. results can be accepted with a 99% confidence level.

Question 6

What is a type 1 error?

Answer 6

Likely to have used p ≤ 0.10 as we accepted our hypothesis when it’s not true.

Question 7

What is a type 2 error?

Answer 7

Likely to have used p ≤ 0.01 as we rejected our hypothesis, believing it’s not true, when actually it is true. Level of significance is too strict.