
How we change what others think, feel, believe and do 





Fratio
Explanations > Social Research > Analysis > Fratio Description  Discussion  See also
DescriptionThe Fratio is a test statistic for multiple independent variables. It is used in ANOVA calculations and calculated as: Fratio = MS_{M} / MS_{R} ... where MS = SS / df Subscripted M means 'Model' and indicates the expected systematic variance. This is often measured as betweenmeasures variation, and the subscript B is consequently often used here. Subscripted R means 'Residual' and indicates the random, unsystematic variance. This is measured as withinmeasures variance, and the subscript W is consequently often used. F can also be calculated with the Pearson correlation coefficient, r: F = r^{2} / (1  r^{2})(n  2) DiscussionA Test Statistic is generally calculated as the ratio of intended, systematic variance divided by the undesirable and unexpected unsystematic variance. Test statistic = systematic variance / unsystematic variance This is typically measured as the sum of squares, SS, then this is: Test statistic = SS_{M} / SS_{R} However, with multiple variables, there are multiple sums of squares. Therefore the Fratio takes the mean of these. See also 

— Contact — Caveat — About — Students — Webmasters — Awards — Guestbook — Feedback — Sitemap — Changes — 

 
