Dear all,

I have a data set with a diagnosis factor (three groups) and four covariates, the fsgd.txt file is pasted below: <!-- /* Font Definitions */ @font-face {font-family:Cambria; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Cambria; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} @page Section1 {size:595.0pt 842.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;}  GroupDescriptorFile 1 Title Thickness-subj Class control Class EHM Class NEHM variables zAge zGender zCTlh zCFF Input c_12 control 0.15 1 -0.66 0.24 Input c_13 control -0.64 1 1.02 -0.09 Input c_14 control 0.28 2 1.14 1.93 Input ehm_1 EHM 0.81 2 0.22 1.17 Input ehm_10 EHM 1.47 2 -0.34 -0.15 Input ehm_16 EHM 1.34 1 -2.18 -0.09 Input nehm_10 NEHM 0.81 2 -0.8 1.11 Input nehm_11 NEHM -0.77 1 -0.06 0.59 Input nehm_13 NEHM -0.64 1 0.63 0.09 ...   The contrast to test whether intercepts are different between groups (ANOVA) would be:

1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 -1 0 0 0 0 0 0 0 0 0 0 0 0   whereas if I want to test for slope differences between groups for the zCFF variable I should write:

0 0 0 0 0 0 0 0 0 0 0 0 1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 -1   An example of post hoc contrast for the former case would be

1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0   and for the latter

0 0 0 0 0 0 0 0 0 0 0 0 1 -1 0   I just need confirmation that everything is fine (or wrong).   Thanks in advance for your help.

Best regards, Jose

--- Jose L. Cantero, Ph.D. Laboratory of Functional Neuroscience Department of Physiology, Anatomy and Cell Biology University Pablo de Olavide Ctra. de Utrera, Km.1 41013 - Seville - Spain - Phone: +34 954 977433 Fax: +34 954 349151 Email: jlcanlor@upo.es http://www.upo.es/neuroaging/es/