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Richard GonzalezRichard Gonzalez

Center Director, Research Center for Group Dynamics, Institute for Social Research
Co-Director, BioSocial Methods Collaborative
Amos N Tversky Collegiate Professor, Psychology and Statistics, LSA
Professor of Integrative Systems and Design, College of Engineering


E-mail: Email Richard Gonzalez
Address: Research Center for Group Dynamics
Institute for Social Research
University of Michigan
426 Thompson Street
Ann Arbor, Michigan 48106
Phone: 734-647-6785

Articles in Statistics/Methods

Developing a new approach to modeling the ground reaction forces in elite human runners

Runners are commonly modeled as spring–mass systems, but the traditional calculations of these models rely on discrete observations during the gait cycle (e.g. maximal vertical force) and simplifying assumptions (e.g. leg length), challenging the predicative capacity and generalizability of observations. We present a method to model runners as spring–mass systems using nonlinear regression (NLR) and the full vertical ground reaction force (vGRF) time series without additional inputs and fewer traditional parameter assumptions.

Estimating a typical path from GPS data

Finding insights from sensor data such as GPS can be tricky. Commuting between home and work may not always follow the same path as some days there are additional stops for errands or alternate routes taken. We propose an algorithm for extracting a typical path from a collection of trips coded by GPS coordinates.

Predicting satisfaction in romantic relationships

We used machine learning to understand which constructs have greater predictive importance for perceived changes in satisfaction since the pandemic began and satisfaction over the prior week.

Machine learning and the selection of statistical interactions

Machine learning does a great job of selecting variables to include in a predictive model. But it will not always obey some desired properties that we implement in most analytic strategies, such as including main effect versions of a predictor if that predictor is included in the model in the form of an interaction with other variables. We compare several existing algorithms and propose a new one to address this issue.

Testing construct validation

We propose a method to test the structure of a covariance matrix for fit against a hypothesized structure using a permutation approach.

Describing hospital stay trajectories the year prior to sepsis

Used a latent profile analysis to examine clusters of individual patient trajectories of hospitalizations one year prior to sepsis. We used two testing cohorts and validated that these trajectory classes predict mortality 90 days after sepsis.

When emotions are both positive and negative

We propose a new measure for assessing mixed emotions over daily activities in older adults. The Activity Affective Complexity score is demonstrated in a subsample of older adults from the Health and Retirement Survey.