Curriculum Vitae

PhD Candidate, Computer Science

Northeastern University · Khoury College of Computer Sciences

Research Focus

I build AI systems that form and maintain accurate models of the people they interact with (their goals, capabilities, beliefs, and affective states) rather than relying on assumed, static, or one-size-fits-all models of the user.

Grounded in computational psychology and Theory of Mind, my work asks how the fidelity of a system's model of a person governs collaboration, trust, and decision-making, studied across five settings:

Cooperative
Human–robot teaming
Adversarial
Cognitive cyber defense
Affective
Decision under emotional load
Social
LLM multi-agent role-play
Clinical
Maternal health
Education

Ph.D. in Computer Science

Sept 2023 – May 2028 (exp.)
Northeastern University, Khoury College of Computer Sciences
Advisor: Stacy Marsella · Cognitive Embodied Social Agents Research (CESAR) Lab · Khoury Distinguished Fellow

B.S. in Data Science & Cognitive Psychology

Sept 2019 – May 2023
Simmons University
Summa Cum Laude · Honors Program · Minors: Computer Science and Spanish Literature
Doctoral Research

Thesis direction: accurate modeling of users (Theory of Mind) as the basis for trustworthy human–AI interaction.

01
Collaborative Theory of Mind · Human–Robot Teaming

Designed grid-world delivery experiments showing that behavioral implicit communication (BIC) under an inaccurate capability model triggers a "conformity trap": humans defer to the robot's signaled plan, reinforcing its wrong assumptions. Developed a capability-elicitation framework that recasts alignment as an exploration–exploitation problem, where targeted probing accelerates convergence to an accurate human model and improves team performance.

02
Adversarial Theory of Mind · Cognitive Cyber Defense

Built the GAMBiT Theory-of-Mind Defender Agent, a PsychSim-based model that infers a network attacker's latent cognitive vulnerabilities from behavior alone. It maintains alternative explicit mental models, each a candidate bias (loss aversion, base-rate neglect, confirmation bias, sunk-cost, availability) with its own utility function, and updates a probability distribution over them as it observes attacker actions, enabling counterfactual reasoning to drive deception and defensive strategy. Validated in human-subject experiments (n = 61) in a simulated enterprise network.

03
Affective Modeling of Decision-Making

Built a web-based escape room and ran an affect-labeling vs. control study identifying behavioral inflection points where unresolved negative affect predicts behavioral collapse, while resolved affect tracks efficient completion, grounding the design of affect-aware interventions that detect bounded-rationality signatures under emotional load.

04
Open-Ended Social Interaction · LLM Multi-Agent Systems

Co-designed the Virtual Human Improv Library, a multi-agent (Orchestrator / Director / Actor) LLM framework for social-skills training through improvised role-play, grounded in Stanislavsky's Active Analysis and framing improvisation as real-time Theory of Mind practice.

05
Coordination & Automation in Practice

Analyzed a 10-month LLM-based ticket-routing deployment at a fintech firm to show that automation relocates rather than eliminates articulation work, surfacing how teams negotiate ownership of ambiguous work.

Industry & Applied

Founding Engineer · Elevare

Apr 2026 – Present
Elevare Health: clinical AI infrastructure for maternal care continuity.
  • ·Building an agentic orchestration layer that operationalizes evidence-based maternal interventions at scale, built on a clinical protocol engine, a safety-critical agentic architecture, and human-on-the-loop operations to improve personalization and early risk detection with every mother served.
  • ·Building the product 0→1: scoping the technical roadmap, defining milestones, and standing up the engineering org's SOPs and tooling stack.

Applied AI/ML Fellow · Advisor360°

Sept 2025 – Apr 2026
  • ·Shipped an LLM + RAG Slack triage system to reduce ticket time-to-resolution and overall volume across production and non-production workflows.
  • ·Translated developer interviews into a routing policy and an internal service-to-team mapping to power an auto-assignment agent achieving ~80% routing accuracy.
  • ·Developed an interactive analytics and retrieval agent that summarizes recurring issues and recommends resolutions via embedding-based matching to historically resolved tickets.

Data Science Researcher · MITRE

May 2022 – Jun 2023
  • ·Automated the National Imagery Interpretability Rating Scale (NIIRS) evaluation workflow in Python, replacing manual scoring with a reproducible ML pipeline.
  • ·Built a predictive model of tracker performance using motion-imagery quality factors, validated on held-out sequences; results peer-reviewed and published at IEEE AIPR.

Research Assistant · Simmons University

Jul 2022 – Jun 2023
  • ·Annotated 500+ utterances with PoLaR and supported a prosody-to-intent pipeline in R, extracting prosodic features (pitch, intensity, duration) and training supervised models.
  • ·Ran feature ablations to quantify contributions of rhythm, stress, and intonation to speaker-intent understanding.
Publications & Preprints
Under Review / In Submission
  1. Hirschmann, S., & Marsella, S. From Implicit to Encoded: How LLM-Based Ticket Routing Reshapes Coordination Practices in a Distributed Engineering Team. Under review, ACM CSCW 2027.
  2. Affect Labeling and Decision-Making in a Virtual Escape Room: A Behavioral Study. Under review, ACII 2026.
Peer-Reviewed
  1. Hirschmann, S., & Marsella, S. (2026). Aligning Teams across the Human–Artificial Divide: Optimizing Collaboration through Strategic Implicit Communication. International Conference on Human-Agent Interaction (HAI 2026).  First author
  2. Dincer, B., Hirschmann, S., & Marsella, S. (2026). Towards a Virtual Human Improv Troupe for Social Skills Training. International Conference on Intelligent Virtual Agents (IVA 2026).
  3. Beltz, B., et al. (incl. Hirschmann, S., & Marsella, S.) (2026). Guarding Against Malicious Biased Threats (GAMBiT): Experimental Design of Cognitive Sensors and Triggers with Behavioral Impact Analysis. Computational Brain & Behavior (Springer).
  4. Hirschmann, S., Tanis, J., Irizarry, N., Martin, B. A., Brennan, M., & Irvine, J. M. (2022). The Relationship Between Tracking Performance and Video Quality. IEEE AIPR Workshop.  First author
  5. Taylor, J., Noboa, N., Hirschmann, S., Tanis, J., Brown, P., & Irvine, J. M. (2023). Investigations into Image Interpretability for Machine Learning.
Workshop Papers & Posters
  1. Hirschmann, S., Yongsatianchot, N., & Marsella, S. (2024). Theory of Mind in Human-Robot Task Collaboration. CHI 2024 Workshop on Theory of Mind in Human-AI Interaction.  First author
Preprints · arXiv
  1. Hans, S., Marsella, S., Hirschmann, S., & Gurney, N. (2025). Security Logs to ATT&CK Insights: Leveraging LLMs for High-Level Threat Understanding and Cognitive Trait Inference. arXiv:2510.20930.
  2. Hans, S., Gurney, N., Marsella, S., & Hirschmann, S. (2025). Quantifying Loss Aversion in Cyber Adversaries via LLM Analysis. arXiv:2508.13240.
  3. Carney, S., Hans, S., Hirschmann, S., Marsella, S., Fonken, Y., Wu, P., & Gurney, N. (2025). Detecting Ambiguity Aversion in Cyberattack Behavior to Inform Cognitive Defense Strategies. arXiv:2512.08107.
  4. Kim, R., Carney, S., Fonken, Y., Hans, S., Hirschmann, S., Marsella, S., Wu, P., & Gurney, N. (2025). Risk Psychology & Cyber-Attack Tactics. arXiv:2510.20657.
Awards
·Khoury Distinguished Fellow · Northeastern University
·Summa Cum Laude & Honors Program · Simmons University
Skills
Programming & Tools
Python · R · SQL · JavaScript · HTML · Git · Figma · Firebase · PsychSim · Qualtrics · Lookback
AI / ML
LLMs & RAG · multi-agent systems · POMDPs & Theory of Mind modeling · Bayesian inference · embedding-based retrieval · experimental ML pipelines
Research
Theory of Mind · computational psychology · human–robot collaboration · cognitive biases · affective computing · experimental design · contextual inquiry · A/B & usability testing · surveys · statistical analysis · data annotation
Languages
Bilingual Spanish / English