ABOUT ME

I am a Ph.D. candidate at Khoury College of Computer Sciences, Northeastern University. I am advised by Prof. Stephen Intille and Prof. Varun Mishra. My research interest lies between the spaces of Human-Computer Interaction, Ubiquitous/Wearables Computing and Personal Health Informatics.

I develop behavioral tracking systems on wearable devices that help individuals monitor the activities and behavioral patterns that matter to them. Most commercial systems rely solely on passive sensing and machine learning models trained on lab-collected datasets, which often fail to generalize to real-world settings and across individuals. My work focuses on building personalized, human-in-the-loop tracking and measurement systems that: (1) collect high-quality behavioral labels to better capture each person’s habits and support personalized recognition models, and (2) enable users to provide feedback with minimal effort. I pursue this goal through:

Developing novel multimodal tracking systems using both in-situ methods (IMWUT’24, CHI’25, PervasiveHealth’24) and retrospective recall methods (IMWUT’25).
Studying users’ uncertainty when self-reporting their behaviors and examining how to incorporate that uncertainty into the tracking process (VIS’25, IMWUT’25).
Investigating how AI/LLMs can support the extraction of high-quality behavioral labels and enable low-effort tracking for health and wellbeing (Ubicomp’25, IMWUT’25).
Integrating behavioral tracking into health-related interactive or intervention systems to improve outcomes (ASSETS’23, JMIR’24).

I received my Bachelor degree in Mathematics and Computer Science from Gustavus Adolphus College in 2022. During my 4 years at Gustavus, I did research under the supervision of Prof. Louis Yu, Jillian Downey and Jacob Siehler.

PUBLICATIONS

A Context-Assisted, Semi-Automated Activity Recall Interface Allowing Uncertainty
Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT’25)
Ha Le, Veronika Potter, Akshat Choube, Rithika Lakshminarayanan, Varun Mishra, and Stephen Intille
[link] [pdf]

A Multi-Agent LLM Network for Suggesting and Correcting Human Activity and Posture Annotations
In Companion of the 2025 on ACM International Joint Conference on Pervasive and Ubiquitous Computing (GENAI4HS Workshop @Ubicomp’25)
Ha Le, Akshat Choube, Vedant Das Swain, Varun Mishra, Stephen Intille
[link] [pdf]

GLOSS: Group of LLMs for Open-Ended Sensemaking of Passive Sensing Data for Health and Wellbeing
Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT’25)
Akshat Choube, Ha Le, Jiachen Li, Kaixin Ji, Vedant Das Swain, Varun Mishra
[link] [pdf]

An Evaluation of Temporal and Categorical Uncertainty on Timelines: A Case Study in Human Activity Recall Visualizations
In 2025 IEEE Visualization and Visual Analytics (VIS’25)
Veronika Potter, Ha Le, Uzma Haque Syeda, Stephen Intille and Michelle Borkin
[pdf]

Feasibility and Utility of Multimodal Micro Ecological Momentary Assessment on a Smartwatch
Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (CHI’25)
Ha Le, Veronika Potter, Rithika Lakshminarayanan, Varun Mishra, and Stephen Intille
[link] [pdf]

Collecting Self-reported Physical Activity and Posture Data using Audio-based Ecological Momentary Assessment
Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT’24)
Ha Le, Rithika Lakshminarayanan, Jixin Li, Varun Mishra, and Stephen Intille
[link] [pdf]

Detecting Sleep Disruptions in Adolescents Using Context-sensitive Ecological Momentary Assessment: A Feasibility Study
Proceedings of the 18th EAI International Conference on Pervasive Computing Technologies for Healthcare (PervasiveHealth’24)
Rithika Lakshminarayanan, Arushi Uppal, Ha Le, James C. Spilsbury and Stephen Intille
[link] [pdf]

mHealth-Based Just-in-Time Adaptive Intervention to Improve the Physical Activity Levels of Individuals With Spinal Cord Injury: Protocol for a Randomized Controlled Trial
JMIR Research Protocols
Rachel L Carey*, Ha Le*, Donna L Coffman, Inbal Nahum-Shani, Mohanraj Thirumalai, Cole Hagen, Laura A Baehr, Mary Schmidt-Read, Marlyn S R Lamboy, Stephanie A Kolakowsky-Hayner, Ralph J Marino, Stephen S Intille, Shivayogi V Hiremath
[link]

A Feasibility Study on the Use of Audio-based Ecological Momentary Assessment with Persons with Aphasia
Proceedings of the 25th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS’23)
Jack Hester, Ha Le, Stephen Intille, Erin Meier
[link]

Relating Consistent Improvement to Overall Performance in a Calculus I Course that Utilizes Standards-Based Grading
Problems, Resources, and Issues in Mathematics Undergraduate Studies (PRIMUS)
Jeff Ford, Rachel Erickson, Ha Le, Kaylee Vick, and Jillian Downey [link]

A study on Channel Popularity in Twitch
Ha Le, Junming Wu, Louis Yu, Melissa Lynn
[pdf][presentation][code] [poster]

One-dimensional Port-and-Sweep Solitaire Armies
Filip Belik, Ha Le, Jacob Siehler
[pdf][presentation]

TEACHING EXPERIENCE

Spring 2020 - now: Introduction to Computer Science I&II (MCS-178,177)
Spring 2021, Spring 2022: Principles of Programming Languages (MCS-287)
Fall 2021: Intro to Computer Organization (MCS-284)
Spring 2020 - Fall 2021: Pre-Calculus, Calculus I, Calculus II, Multivariables Calculus (MCS-119,121,122,222)