type 1 and type 2 errors Flashcards
What is meant by a type 1 error? (2m)
- researcher has used a lenient p value
- think the results are significant
- actually due to chance or error
- wrongly accept alternative hypothesis
- wrongly reject null hypothesis
What is meant by a type 2 error? (2m)
- researcher has used a stringent p value
- think the results are not significant
- when they could be significant
- wrongly accept null hypothesis
- wrongly reject alternative hypothesis
What is the difference between type 1 and 2 errors? (2-4m)
- in a type 1 error the null hypothesis is rejected when it is true
- whereas
- in a type 2 error the null hypothesis is accepted when it is false
Example of a lenient p value…
- p < 0.1
- less than 10% probability results due to chance/error
- more than 90% probability results due to IV affecting DV/relationship co-variables
Example of a stringent p value…
- p < 0.01
- less than 1% probability results due to chance/error
- more than 99% probability results due to IV affecting DV/relationship co-variables
Example of a stringent p value…
- p < 0.01
- less than 1% probability results due to chance/error
- more than 99% probability results due to IV affecting DV/relationship co-variables
Why do psychologist use the 5% significance level?
- p < 0.05
- is a conventional significance level
- strikes a balance between the risk of making a type 1 and 2 error
How to check for a type 1 error…
- compare calculated value
- to critical value
- from a more stringent p value
- if results still significant NOT type 1
- if results now not significant IT IS type 1
How to check for a type 2 error….
- compare calculated value
- to critical value
- from a more lenient p value
- if results still not significant NOT type 2
- if results now significant IT IS type 2
Writing frame:
The researcher DID/DID NOT make a TYPE1/TYPE 2 error because when using a more STRINGENT/LENIENT p value of … for a ONE-TAILED/TWO-TAILED test where N=… the calculated value of … is GREATER/LESS than the critical value … and is STILL/NOW SIGNIFICANT/NOT SIGNIFICANT.
Therefore the researcher DID/DID NOT wrongfully ACCEPT/REJECT the alternative hypothesis and DID/DID NOT wrongfully ACCEPT/REJECT the null hypothesis.
They can be more than …% sure there is a significant difference/correlation between … and less than …% sure their results are due to chance/error.