Difference testing - Prametric testing

Question 1

Rules which must be followed when using parametric statistic tests

Answer 1

data must have been measured on a parametric scale (interval/ratio)
the data must have come from a population whose distribution was normal
The 2 groups must have similar variance

Question 2

Advantages of parametric statistics

Answer 2

more powerful (less type 2 errors)

sometimes easier to understand as actual scores are used

Question 3

the t test

Answer 3

if we test differences with a t test, what we are actually testing is the following null hypothesis: our samples come from the same population
T tests looks at the data, assumes that the data are normal distributed and compares means and standard deviations