Mixed Models in the Wild: Techniques, Workflows, and Challenges - Online Course

ABSTRACT

Statistical models that account for grouping or clustering in data (variously called multilevel, mixed, or hierarchical models) have been around since the 1950s but have continually grown in scope and flexibility. Any time we have observations that violate the standard assumption of independence–because multiple observations are drawn from the same individual, classroom, species, or geographic region–our statistical models must incorporate this dependence structure or else risk inaccuracy and overconfidence.

While the computational tools for fitting and evaluating these models are ever more powerful and convenient, that power brings problems as well. When the data are too sparse for a complex model, how should we simplify or adjust the model? How do we choose among a bewildering range of options? How well do these complex models scale to big data, however defined?

The first hour of this seminar reviews the ideas of mixed models, discusses available software platforms, and briefly outlines some of the challenges in estimation and inference for these models. The second hour presents a general workflow for mixed modeling, illustrated with one or more examples. The third hour revisits the challenges from the first hour in more detail and discusses open questions. Examples will primarily be drawn from ecology and psychology, but the techniques are broadly applicable. Each hour will include a mix of examples, methods, and discussion, including responding to your questions.

The course is not hands-on, but it will include analyses using R.

Attendees will benefit most from the seminar if they have some knowledge (even dimly remembered) of basic statistics (e.g., normal distribution, hypothesis testing) and linear regression. Some knowledge of R will make it easier to follow the examples.

This Distinguished Speaker Series seminar will consist of three hours of lecture and Q&A, held live* via the free video-conferencing software Zoom.

*The video recording of the seminar will be made available to registrants within 24 hours and will be accessible for four weeks thereafter. That means that you can watch all of the class content and discussion even if you cannot participate synchronously.

Closed captioning is available for all live and recorded sessions. Captions can be translated to a variety of languages including Spanish, Korean, and Italian. For more information, click here.