Question

18.What information does the F ratio on the SPSS output for an independent samples t test provide? That is, what assumption does it test?

19. Explain briefly why there are two different versions of the t test on the SPSS printout and how you decide which one is more appropriate.

20.What is η2?

Answer 1

(18) Assumptions we want to test as follows-

(a) whether two independent sample have been drawn from normal population with same variance.

(b) whether two independent estimates of population variance are homogenious or not.

SPSS output provides us whether population variance of two groups are homogeneous or not .

(19) There are always two columns, one for equal population varince, second for unequal population variance assumed. Both column has own degree of freedom, t statistics, mean difference, confidence interval etc. you chosse what is your interest, to equal or unequal population variance.

(20) η2 is correlation ratio. η2 includes in when we apply F test for tesing the significance of observed sample corrleation ratio.