Hi Saqib, 

For the design matrix that you have given, [-1 1] will test whether the group modelled by the first column is LESS THAN the group modelled by the second column. I hope that helps. 

Andrew

Originally posted by Saqib Mamoon:

Hi Andrew,

I read the articles and manuals on NBS, but I need some clarification. Here, you stated the  [-1 1] and [1 -1] to test for MCI>CN and MCI<CN. Here, the greater sign is towards -1. However, in the NBS manual 1.2, it is stated like:

Design Matrix:

0 1
0 1
0 1
1 0
1 0
1 0

"Given the above design matrix, the following contrast vector specifies a onesided t-test assessing whether the group modeled by the first column is greater than the group modeled by the second column Example contrast [1 -1] with group1 > group 2. Here, the greater sign is towards 1.

Does direct NBS infer the greater smaller direction differently, or it has something to do with design matrix?

Thank you for your valuable time and kind consideration. 

 

Best regards,

Saqib