Type I and Type II Errors

Question 1

What is there a possibility of in any outcome from a statistical test?

Answer 1

the possibility that chance causes the result

Question 2

What does it mean if chance caused the result?

Answer 2

the researchers will have made an error

Question 3

What is the likelihood of making an error equal to?

Answer 3

the level of significance e.g. 5% if p<=0.01

Question 4

What is a type one error?

Answer 4

-A false positive result (optimistic error). -outcome of the statistical test suggests the result is significant, but in reality, the positive outcome was due to chance
-null hypotheses has been wrongly rejected (and the alternative hypothesis has been wrongly accepted).
-More likely to occur with a lenient level of significance (e.g. p≤0.1)

Question 5

What is a Type two error?

Answer 5

-false negative result (pessimistic error).
-outcome of the statistical test suggests the result is not significant, but in reality, the observed effect was actually due to the variables being investigated and not due to chance.
-null hypotheses has been wrongly accepted (and the alternative hypothesis has been wrongly rejected).
• More likely to occur with a strict level of significance (e.g. p≤0.01)

Question 6

What should you do to check if you have a type one error?

Answer 6

test your calculated value against a more stringent significance level to check if you have a type one error