probability, significance, errors in research

Question 1

significance meaning

Answer 1

statistical measure to show how certain we are that the result is real

• if significant , we reject the null hypothesis , and accept alternative hypothesis

Question 2

difference between null and alternative hypo

Answer 2

null- no diff /correlation
alternative - difference/correlation exists

Question 3

what does a p-value of 0.05 mean

Answer 3

5% probability that results happened by chance
95% confidence levels in findings

if human costs are involved, e.g drug trials p= 0.01 is used for greater certainty

Question 4

type 1 errors

Answer 4

• false positive (optimistic error)
  incorrectly rejecting null hypo
• claiming a difference when none actually exists

Question 5

type 2 error

Answer 5

false negative (pessimistic error)
incorrectly accepting null hypo