Leveraging Collaborative-Filtering for Personalized Behavior Modeling: A Case Study of Depression Detection among College Students

Jennifer Mankoff

Abstract:

The prevalence of mobile phones and wearable devices enables the passive capturing and modeling of human behavior at an
unprecedented resolution and scale. Past research has demonstrated the capability of mobile sensing to model aspects of
physical health, mental health, education, and work performance, etc. However, most of the algorithms and models proposed in
previous work follow a one-size-fits-all (i.e., population modeling) approach that looks for common behaviors amongst all users,
disregarding the fact that individuals can behave very differently, resulting in reduced model performance. Further, black-box
models are often used that do not allow for interpretability and human behavior understanding. We present a new method to
address the problems of personalized behavior classification and interpretability, and apply it to depression detection among
college students. Inspired by the idea of collaborative-filtering, our method is a type of memory-based learning algorithm. It
leverages the relevance of mobile-sensed behavior features among individuals to calculate personalized relevance weights,
which are used to impute missing data and select features according to a specific modeling goal (e.g., whether the student has
depressive symptoms) in different time epochs, i.e., times of the day and days of the week. It then compiles features from
epochs using majority voting to obtain the final prediction. We apply our algorithm on a depression detection dataset collected
from first-year college students with low data-missing rates and show that our method outperforms the state-of-the-art
machine learning model by 5.1% in accuracy and 5.5% in F1 score. We further verify the pipeline-level generalizability of
our approach by achieving similar results on a second dataset, with an average improvement of 3.4% across performance
metrics. Beyond achieving better classification performance, our novel approach is further able to generate personalized
interpretations of the models for each individual. These interpretations are supported by existing depression-related literature
and can potentially inspire automated and personalized depression intervention design in the future