Flexible, affordable statistics education.
Designed to help you master the software you need to enhance your skills and the practical experience you need to get ahead.
Designed to help you master the software you need to enhance your skills and the practical experience you need to get ahead.

Mixed and Hierarchical Linear Models
taught by Andrzej Galecki
This course will explain the basic theory of linear and non-linear mixed effects models, including hierarchical linear models. It will outline the algorithms used for estimation, primarily for models involving normally distributed errors, and will provide examples of data analysis. The course aims at providing a basic understanding and knowledge of the mixed effect models that will allow you to use them in practice.
Instructor(s):Researchers analyzing longitudinal or clustered data sets arising from experiments, clinical trials, or surveys, where the data are not amenable to simple statistical analysis and correlated observations need to be accounted for.
Dates:Add $50 service fee if you require a prior invoice, or if you need to submit a purchase order or voucher, pay by wire transfer or EFT, or refund and reprocess a prior payment. Please use this printed registration form, for these and other special orders.
Courses may fill up at any time and registrations are processed in the order in which they are received. Your registration will be confirmed for the first available course date, unless you specify otherwise. Multiple course registrations may be entitled to tuition discounts; read more.
Mixed and Hierarchical Linear Models
taught by Andrzej Galecki
This course will explain the basic theory of linear and non-linear mixed effects models, including hierarchical linear models (HLM). It will outline the algorithms used for estimation, primarily for models involving normally distributed errors, and will provide examples of data analysis. The course aims at providing a basic understanding and knowledge of the mixed effect models that will allow you to use them in practice. To achieve this aim, the use of procedures in R and SAS to fit mixed effects models to real data sets will be presented and discussed. The instructors will also demonstrate model fitting using other procedures as requested.
Mixed models are a powerful class of models used for the analysis of correlated data. Examples of correlated data include, but are not limited to, clustered data, repeated observations, longitudinal data, multiple dependent variables, spatial data or data from population pharmacokinetic/pharmacodynamic studies. A key feature of mixed models is that, by introducing random effects in addition to fixed effects, they allow you to address multiple sources of variation, e.g. in the longitudinal study they allow you to take into account both within- and between- subject variation.
The course will detail a basic theory of mixed models and will provide an overview of estimation methods, with emphasis on the linear case. Concepts of mixed models will be illustrated with examples analyzed using PROC/MIXED in SAS and functions in R. Most of the illustrations can also be done in Stata and/or SPSS (not all features are available in those packages, and the instructor is not familiar with them). Participants are strongly encouraged to contribute to discussions on the online course discussion board, where exchanges of examples, software code, and ideas about modeling approaches enhance conceptual and theoretical material with practical solutions.
Prerequisite(s):
HOMEWORK:
Homework in this course consists of short answer questions to test concepts, guided data analysis problems using software, guided data modeling problems using software, and end of course data modeling project.
Organization of the Course:This course takes place over the internet at the Institute for 4 weeks. During each course week, you participate at times of your own choosing - there are no set times when you must be online. Course participants will be given access to a private discussion board. In class discussions led by the instructor, you can post questions, seek clarification, and interact with your fellow students and the instructor.
The course typically requires 15 hours per week. At the beginning of each week, you receive the relevant material, in addition to answers to exercises from the previous session. During the week, you are expected to go over the course materials, work through exercises, and submit answers. Discussion among participants is encouraged. The instructor will provide answers and comments, and at the end of the week, you will receive individual feedback on your homework answers.
The course text is Linear Mixed Models: A Practical Guide using Statistical Software by B. T. West, K. B. Welch, and A. T. Galecki, with contributions from B. W. Gillespie, which you can order from CRC Press, or by using this form. CRC Press typically gives students a generous discount when students order the text using the above form (not by ordering the text online).
PLEASE ORDER YOUR COPY IN TIME FOR THE COURSE STARTING DATE.
Concepts of mixed models will be illustrated with examples analyzed using PROC/MIXED in SAS and functions in R. Most of the illustrations for the linear case will have parallel examples in Stata and/or SPSS (not all features are available in those packages), but instructor is familiar only with SAS and R. TA can provide some help with Stata; no help is available for SPSS. Exercises should be doable with SAS, R, Stata, or SPSS. For information on obtaining software, click here.
Mixed and Hierarchical Linear Models
taught by Andrzej Galecki