Usage Note 37932: When doing a screening analysis using Fit Model, what are the "Orthog Coded" and "Orthog t-Test" columns?
The "Orthog Coded" and "Orthog t–Test" columns are displayed when doing effect screening for a model with correlated parameter estimates.
The Orthog Coded column shows orthogonalized estimates. These are used in the pareto plot because this plot partitions the sum of the effects and partitioning requires orthogonality. These are computed by premultiplying the column vector of Original estimates by the transformation matrix shown by selecting Show Transformation from the Effect Screening pop-up menu in Version 3, or opening the Transformation to make uncorrelated table in Version 4 and higher, and then multiplying by the standard error of the model. The transformation matrix is the Cholesky root of X`X. These estimates depend on the model order unless the original design is orthogonal.
The "Orthog t-Test" values (formerly labeled "normalized") are constructed to make the parameter estimates independent and identically distributed. These are used in the normal plot, which requires these properties. The p–values associated with these estimates (given in the Prob>|t| column) are equivalent to type I sequential tests. Consequently, if the parameters of the model are correlated, these estimates and their p–values depend on the order of terms in the model. These estimates are computed by dividing the orthogonalized estimates ("Orthog Coded" estimates) by their standard errors.
Operating System and Release Information
|Product Family||Product||System||SAS Release|
|JMP Software||JMP software||Macintosh|
|Microsoft Windows XP 64-bit Edition|
|Microsoft® Windows® for x64|
|Microsoft Windows 2000 Professional|
|Microsoft Windows Server 2003 Standard Edition|
|Microsoft Windows XP Professional|
|Linux for x64|
|Date Modified:||2009-11-20 12:06:26|
|Date Created:||2009-11-20 11:05:50|