type 1 and type 2 errors

Question 1

type 1 error

Answer 1

ERROR OF OPTIMISM

• when the null hypothesis is rejected and alternative is accepted when it should have been the other way around (so null is actually true)
• most likely if significance level if too lenient (high) (so more likely at 10% than 5%)

Question 2

type 2 error

Answer 2

ERROR OF PESSIMISTS

• when the null hypothesis is accepted and the alternative is rejected when it should have been the other way around (so alternative is actually true)
• more likely if significance level is too stringent (low) (so more likely at 1% than 5%)

Question 3

consequence of type 1 error

Answer 3

• researcher publishes false data + other researchers waste time trying to replicate findings
• scientific journals waste resources publishing replications showing no difference

Question 4

consequence of type 2 error

Answer 4

• researcher may think their study is not good enough to find an affect so improves experiment (eg larger sample) when they may not have enough funding for this
• researcher gives up research that might have provided important findings, scientific journals don’t publish findings of no significance