Fixed effects, random coefficients, and centering

Steve Raudenbush, Lewis-Sebring Professor of Sociology, Chairman of the Committee on Education at the University of Chicago, and main author of the well-known HLM program, discusses the fixed effect random coefficient (FIRC) model and its implications for causal inference for multilevel data. A new feature in HLM, this feature is computationally convenient, with no dummy variables and no centering. The Tennessee STAR data is used as illustration in this 45 minute webinar.

This is the first in a series of webinars by Professor Raudenbush. A second webinar, discussing the use of the newly implemented profile likelihood plots feature in HLM in inference for variance components in hierarchical linear modeling, will be available soon. 

Remembering Professor R. Darrell Bock

It is with great sadness that we acknowledge the passing of R. Darrell Bock. Among his many incredible contributions to science and psychometrics, Professor Bock was also co-founder and long-time President of SSI. The company would never have existed without Professor Bock and the history of scientific software would have been drastically different without his contributions. The staff at SSI express their heartfelt condolences to Professor Bock’s family and friends. For more information on his amazing life and contributions, you can find his obituary (penned by Robert Gibbons and Tania Bock) here, as well as an article remembering his life and contributions in UChicago News.

Updated version of HLM 8.2

SSI is pleased to announce an update to HLM 8.2. The update contains a new feature and a bug fix. Users with active SSI Live™ HLM subscription licenses can obtain this update free of charge by logging into My Account and downloading the updated version.

List of updates:

  • Previously, users could only import older Excel spreadsheets (*.xls extension). The option to import current Excel spreadsheets (*.xlsx) has been added to the program.
  • A bug with some spatial models running out of memory has been reported. This has been fixed.