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# st: Re: Using margins

 From Arti Rayit To statalist@hsphsun2.harvard.edu Subject st: Re: Using margins Date Fri, 4 Feb 2011 15:11:37 +0000 (GMT)

```Hello,
I am trying to teach myself how to use margins and I am using a simple oneway
dataset from the manual.
. anova weight treatment
. margins treatment, post asbalanced
. test (1.treatment = 2.treatment) (1.treatment = 3.treatment) (1.treatment =
4.treatment) (2.treatment = 3.treatment) (2.treatment = 4.treatment)
(3.treatment = 4.treatment), mtest(bon)

( 1)  1bn.treatment - 2.treatment = 0
( 2)  1bn.treatment - 3.treatment = 0
( 3)  1bn.treatment - 4.treatment = 0
( 4)  2.treatment - 3.treatment = 0
( 5)  2.treatment - 4.treatment = 0
( 6)  3.treatment - 4.treatment = 0
Constraint 2 dropped
Constraint 4 dropped
Constraint 5 dropped

---------------------------------------
|        chi2     df       p
-------+-------------------------------
(1)  |       63.83      1     0.0000 #
(2)  |       16.13      1     0.0004 #
(3)  |       17.26      1     0.0002 #
(4)  |        9.80      1     0.0105 #
(5)  |        8.95      1     0.0167 #
(6)  |        0.02      1     1.0000 #
-------+-------------------------------
all  |       64.37      3     0.0000
---------------------------------------

Yet when I run the example:
. oneway weight treatment,bon

Analysis of Variance
Source              SS         df      MS            F     Prob > F
------------------------------------------------------------------------
Between groups      5295.54433      3   1765.18144     21.46     0.0013
Within groups      493.591667      6   82.2652778
------------------------------------------------------------------------
Total             5789.136      9   643.237333

Bartlett's test for equal variances:  chi2(3) =   1.3900  Prob>chi2 = 0.708

Comparison of Average weight in grams by Fertilizer
(Bonferroni)
Row Mean-|
Col Mean |          1          2          3
---------+---------------------------------
2 |   -59.1667
|      0.001
|
3 |     -33.25    25.9167
|      0.042      0.122
|
4 |      -34.4    24.7667      -1.15
|      0.036      0.146      1.000
I get completely different adjusted probabilities.
What am I misunderstanding and doing wrong.
Arti

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```