06-10-2015 08:59 AM
I've trouble interpreting the GLIMMIX and MIXED output. May I request to shed some lights with the documents (or some useful hints) which could be understandable easily. Although I read the documents available in support.sas I still have difficulties to follow the output.
I'm naive to these procs.
Thanks in advance for your guidance.
06-10-2015 10:25 AM
With such a broad and general question, you must get the book SAS for Mixed Models, second edition (2006) by Littell et al. You have to buy this, but it is absolutely essential! Anyone doing anything with mixed models needs to have a copy of this book.
06-11-2015 08:28 AM
A preliminary warning: These are complex models that are easy to misuse and misinterpret. A substantial amount of study will be necessary to use these models well.
First, I'd ask if you are using multilevel models to deal with longitudinal data or clustered data.
If it's longitudinal data then I recommend two books by the "two Geerts":
Mollenberghs and Verbeke, Linear Mixed Models for Longitudinal Data - for MIXED
Mollenberghs and Verbeke, Models for Discrete Longitudinal Data - for GLIMMIX
I find these considerably clearer than Littel et al (which is also a good book, but demands more math)
An even easier book is Hedeker and Gibbons Longitudinal Data Analysis but it is less specific to SAS.
If you have data that is clustered, then one good book (especially if you have educational data) is Hierarchical Linear Models by Raudenbush and Bryk; it's not SAS specific, but it will provide the background you need.