Research Projects
NSF-funded collaborative research developing algorithms and open-source software for multi-task learning, with applications spanning biomedical informatics and beyond.
Multi-task learning has emerged as a powerful paradigm within machine learning, enabling models to simultaneously learn multiple related tasks by sharing representations and leveraging commonalities across domains. This approach is especially valuable in settings where labeled data is scarce for individual tasks but abundant across a collection of related problems. By jointly optimizing across tasks, the model captures richer feature representations and often generalizes more effectively than training each task independently. The theoretical foundations of multi-task learning draw from regularization theory, Bayesian inference, and optimization, yielding algorithms that are both principled and practical for real-world deployment.
Biomedical informatics presents uniquely challenging opportunities for machine learning, given the high-dimensional, heterogeneous, and often noisy nature of clinical and genomic data. Electronic health records, medical imaging, and biomarker discovery all benefit from methods that can integrate diverse data sources while maintaining interpretability. Large-scale learning algorithms must contend with missing values, class imbalance, and the need for robust validation across populations. Multi-task learning is particularly well-suited here, as many diseases share underlying biological mechanisms, and predictive models can benefit from jointly learning across related conditions or patient cohorts to improve both accuracy and clinical relevance.
The development of open-source software for machine learning research is essential for reproducibility, collaboration, and the rapid advancement of the field. By releasing well-documented implementations of algorithms, researchers enable others to build upon their work, benchmark new methods, and apply cutting-edge techniques to domain-specific problems. Scalable implementations are especially critical as datasets grow in size and complexity, requiring efficient data structures, parallel computation, and careful memory management. Open-source toolkits also serve as educational resources, helping train the next generation of data scientists and machine learning practitioners in both academic and industrial settings.
Large-scale data analytics demands algorithms that are not only accurate but also computationally efficient and memory-aware. As datasets grow to terabytes and beyond, traditional approaches that assume data fits in memory become impractical. Distributed computing frameworks, stochastic optimization methods, and online learning algorithms offer pathways to scalable analysis without sacrificing model quality. Feature selection, dimensionality reduction, and sparse modeling techniques further help manage complexity by identifying the most informative signals within massive datasets. These methodological innovations ensure that the insights derived from big data remain actionable, interpretable, and grounded in rigorous statistical reasoning.
III: Small: Collaborative Research: Structured Methods for Multi-Task Learning
Principal Investigators: Jiayu Zhou (Leading PI, Michigan State University), Shuiwang Ji (PI, Washington State University)
This NSF CRII project addresses the challenge of learning from multiple related tasks simultaneously. Human learners routinely transfer knowledge across related tasks — a child can distinguish chairs from tables after only a few examples. Standard machine learning programs, by contrast, typically require large volumes of labeled data for each new task. This research develops structured methods that enable effective inter-task knowledge transfer, tackling problems that fall outside the scope of conventional multi-task learning approaches.
The project includes the development of open-source software tools to make these methods accessible to the broader research community.
CRII: III: Integrating Domain Knowledge via Interactive Multi-Task Learning
Principal Investigator: Jiayu Zhou | Students Supported: Kaixiang Lin, Qi Wang
In most real-world applications, machine learning tasks are closely related to one another, and human domain experts can often provide indispensable insights that pure data-driven models miss. This NSF CRII project investigates interactive multi-task learning frameworks that integrate domain knowledge from human experts directly into the model-building process.
A key application is the construction of disease progression models in biomedical informatics, where clinician knowledge can guide and constrain learned representations. The project also incorporates educational components to train the next generation of researchers in these methods.
Both projects are supported by the National Science Foundation under the CRII program.