sdm-help-list > How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
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Sep 23, 2020  03:09 AM | Chengyu Wang
How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
Hi,

I recently conducted a linear model to compare the effect of variate 1 (code as 0 and 1, i.e two group comparison) adjusted for variate 2 as a covariate, how should I set the matrix, "variate 1+variate 2,0+1+0+0+0,50" or "variate 1+variate 2,0+1+1+0+0,50"? And how to interpret the linear model results since the meta-analysis inherently involves a comparison of the functional alteration between patient vs healthy control?

Thanks for answering all these questions. I really appreciate any help!

Best,
Chengyu
Oct 29, 2020  01:10 PM | Yizhen Li
RE: How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
Hello,i am also confused of the linear model. When i used this to compare two groups ,i got no results.I set sdm_stable a group variable to seperate the two groups(A for-1 and B for 1).But My model is ''modelline = mi_lm ,0+0+0+0+0,50,,1''    I just do not understant the 0 or 1 in this part.Have you solved this ploblem?
Oct 30, 2020  03:10 PM | Lydia Fortea - Instituto de Investigaciones Biom├ędicas August Pi i Sunyer (IDIBAPS)
RE: How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
Hi Chengyu,

To set the linear model with variable1 adjusted by variable2 the command should be LinearModel = mi_lm var1+var2,0+1+0+0+0,50,,1.

The results indicate if there is a correlation (positive of negative) of that variable with the main results. Eg. if i have a Z value positve in a certain area when studying adult sample, that mean that area is stronger activated (in comparison of patients with healthy controls) when the sample are adults.

Kind Regards,
Lydia
Oct 30, 2020  03:10 PM | Lydia Fortea - Instituto de Investigaciones Biom├ędicas August Pi i Sunyer (IDIBAPS)
RE: How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
Hi,

You should specify one group as 0 and the other 1 (instead of -1 and 1). When selecting the variables in your model, be sure you put  1 for the hypothesis you want to test.

Kind regards
Nov 2, 2020  02:11 AM | Yizhen Li
RE: How to set 'model and hypothesis' and interpret the result in the Linear Model of V6.21
Thank you so much! That works!