Type I and Type II errors

Question 1

What is a type 1 error?

Answer 1

Rejecting the null hypothesis when it is actually true, thinking there are significant differences

Question 2

What is a type 2 error?

Answer 2

Accepting the null hypothesis when it is actually wrong and there is a significant difference

Question 3

Example of a type 1 error?

Answer 3

Diagnosing a man as pregnant when he isn’t because you have rejected the null hypothesis and accepted the experimental and thought there is a significant difference

Question 4

Example of type 2 error?

Answer 4

Diagnosing a pregant women as not pregnant because you have accepted the null hypothesis wrongly and rejected the experimental thinking there aren’t sig. diffs

Question 5

When are results often accepted as statistically significant?

Answer 5

If there is a 1 in 20 likelihood or less of the results being due to chance (p<0.05)

Question 6

When are results nearly always accepted as statistically significant?

Answer 6

If there is a 1/100 likelihood or less of the results being due to chance (p<0.01)

Question 7

What level of significance is chosen if the experiment has been done before and the results have been found to be true?

Answer 7

p<0.01

Question 8

What level of significance is chosen if the experiment hasn’t been done before and there is minimal research in the area?

Answer 8

p<0.05 but depends on how serious the consequences of the study might be

Question 9

When might the significance p<0.20 be used?

Answer 9

When there is no research in the area