Satterthwaite degrees of freedom [Regulatives / Guidelines]

posted by Helmut Homepage – Vienna, Austria, 2008-03-06 14:57 (5984 d 11:48 ago) – Posting: # 1663
Views: 14,973

Dear SKR!

❝ My question is can we manually calculate MIXED ANOVA results?

Theoretically yes, practically no.
The solution of a linear mixed effect model (this is not an ANOVA!) is based on a numeric iterative procedure – so if you have truly a lot of spare time, you should be able to do it… :lol3:

❝ One more thing is, what DDFM=SATTERTH; indicates?

DDFM: D (?) Degrees of Freedom
SATTERTH: Welch-Satterthwaite approximation for unequal variances / sample sizes (i.e., unbalanced data)$$\nu \approx \frac{\left (\frac{s_{1}^{2}}{n_1}+\frac{s_{2}^{2}}{n_2}\right )^2}{\frac{s_{1}^{4}}{n_1(n_1-1)}+\frac{s_{2}^{4}}{n_2(n_2-1)}}$$

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

UA Flag
 Admin contact
23,127 posts in 4,859 threads, 1,646 registered users;
57 visitors (0 registered, 57 guests [including 11 identified bots]).
Forum time: 03:46 CEST (Europe/Vienna)

No problem can stand the assault of sustained thinking.    Voltaire

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz