Bioequivalence and Bioavailability Forum

Oops! df! [Study As­sess­ment]

posted by d_labes  – Berlin, Germany, 2019-02-21 11:54 (1882 d 20:42 ago) – Posting: # 19956
Views: 10,058

Dear Helmut,

❝ ❝ ❝ Degrees of freedom?

❝ ❝

❝ ❝ Presumable YES. ... Maybe they are or can be different, IIRC. Why ever.

❝

❝ ANOVA: 30 (well…)

❝ TaaTP:

❝   B/A 8

❝   C/A 8

❝   D/A 9

❝

❝ 8? 9?? What the heck? ... I don’t get it.

Ok, something like that I have expected.
Let's try a 'theoretical' approach. Since we do not recode the periods and / or sequences the df can be obtained via (model without decomposition of the subjects effect into sequence and subject within sequence, design 4x4)

source    df
-------------------------------
Total    2*n-1 = 23
treat    t-1   =  1
period   p-1   =  3
subject  n-1   = 11
-------------------------------
error    n-4   = 23-1-3-11 = 8
-------------------------------

So far so good. Two numbers of three 'explained'. Why the heck the comparison D/A has one degree of freedom more: Duno .
We have already noticed a similar effect for the EMA 'crippled' model for replicate designs. See this post.

Nevertheless: The degrees of freedom are different for the 2x2 design and the design of the TaaTP. We can mimic the df's, at least approximately, if we use the robust df's.

Complete thread:

• CV values in BE studies: intra, or inter, or total? Elena777 2018-01-20 12:31 
  • CV values in BE studies: intra, or inter, or total? jag009 2018-01-20 19:18
    • CV values in BE studies: intra, or inter, or total? Elena777 2018-01-20 21:10
      • CV values in BE studies: intra, or inter, or total? jag009 2018-01-21 03:17
        • CV values in BE studies: intra, or inter, or total? Elena777 2018-01-21 08:21
  • CV values in BE studies: intra, or inter, or total? Helmut 2018-01-21 17:33
  • CV values in BE studies: intra, or inter, or total? ElMaestro 2018-01-21 18:17
    • CV values in BE studies: intra, or inter, or total? Elena777 2018-01-27 09:57
      • CV values in BE studies: intra, or inter, or total? Louis52 2018-02-07 20:22
        • CV values in BE studies: intra, or inter, or total? Helmut 2018-02-07 20:31
          • CV values in BE studies: intra, or inter, or total? Rosy 2019-02-19 18:33
            • PowerTOST: CVfromCI Helmut 2019-02-20 13:00
              • PowerTOST: CVfromCI -> CI.BE d_labes 2019-02-20 14:12
                • Oops! Helmut 2019-02-20 15:32
                  • Oops! df? d_labes 2019-02-20 19:45
                    • Oops! df? Helmut 2019-02-20 20:43
                      • Oops! df!d_labes 2019-02-21 10:54
                      • Oops! df? zizou 2019-02-21 11:33
                        • Oops! df? nobody 2019-02-21 12:42
                        • All the answers are here d_labes 2019-02-21 14:49
              • PowerTOST: CVfromCI Rosy 2019-02-20 15:25
                • type known.designs() in PowerTOST Helmut 2019-02-20 16:14
                  • type known.designs() in PowerTOST Rosy 2019-02-20 17:14