About
I am a PhD student at the Technion – Israel Institute of Technology, advised by Ofra Amir and Amir Feder. My research sits at the intersection of natural language processing, computational argumentation, and causal inference.
I study how to steer and explain the high-level choices language models make while they reason. In STATe-of-Thoughts (COLM 2026), I replace temperature sampling in tree search with interpretable textual interventions, so each generated output carries a record of the choices that produced it. In APPEAL (TADA 2026, oral), I move from association to causation, estimating how much each of those expert-specified choices actually contributes to an argument’s persuasiveness.
This fall (October 2026 – January 2027) I am a Student Researcher at Google Research in Mountain View. In Summer 2025 I was an Applied Scientist Intern at Amazon Science in Seattle, and over Summer 2026 I was a visiting student researcher at Princeton University through the VSRC program, hosted by Brandon Stewart.
Before my PhD I was a software engineer at Google, where I built reinforcement-learning agents for recommendation systems and pre-trained on-device language models with federated learning. Earlier, I studied discourse structure and argumentation in Claire Cardie’s lab at Cornell University. My MSc at the Technion, advised by Yonatan Belinkov, produced DEPTH—a discourse-oriented pre-training objective for encoder-decoder language models.
I have served as a teaching assistant for machine learning, natural language processing, transformers, and introduction to computing (Python) at the Technion, and for operating systems and NLP at Cornell.
- Advisors
- Ofra Amir & Amir Feder
- Education
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PhD, Data & Decision Sciences, Technion (2024–)
MSc CS, Technion (2021–2024)
BSc CS, Cornell (2015–2019) - Institution
- Technion – Israel Institute of Technology
- Currently
- Student Researcher, Google Research (Fall 2026)
- Previously
- Princeton (VSRC) · Amazon Science · Google Research · Google Brain · Intel · Mellanox · Cornell
- Honors
- VATAT Prize for Student Research in Data Science, Tech.AI (2026, ₪15,000)
Oral presentation, TADA 2026 - Interests
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- LLM reasoning
- Causal inference
- Inference-time compute
- Persuasion
- Interpretability
- zachary@campus.technion.ac.il
News
- Oct 2026 Starting as a Student Researcher at Google Research in Mountain View (through January 2027).
- Sep 2026 APPEAL was accepted as an oral presentation at New Directions in Analyzing Text as Data (TADA) 2026. Talk at UC Berkeley on October 5 [OpenReview].
- Aug 2026 Invited talk, “Steering How Language Models Reason,” at Susan Murphy’s Statistical Reinforcement Learning Lab, Harvard.
- Jul 2026 STATe-of-Thoughts was also accepted to the Workshop on Agent Behavior (WAB) at COLM 2026. Poster on October 9 [OpenReview].
- Jul 2026 Received the VATAT Prize for Student Research in Data Science (₪15,000) from Tech.AI, the Technion’s AI research center. The prize is funded by VATAT, the Planning and Budgeting Committee of Israel’s Council for Higher Education. It is awarded to a small number of Technion students each year, and this track recognizes research conducted under joint supervision (here, by Ofra Amir and Amir Feder).
- Jul 2026 STATe-of-Thoughts was accepted to the Conference on Language Modeling (COLM) 2026. Poster in San Francisco on October 8 [COLM page · arXiv · code].
- Jul–Sep 2026 Visiting student researcher at Princeton through VSRC, hosted by Brandon Stewart.
- Jun 2026 Invited talk on STATe-of-Thoughts at the NVIDIA Tel Aviv research lab.
- Feb 2026 STATe-of-Thoughts preprint released on arXiv.
- Dec 2025 Invited talk on STATe-of-Thoughts at Matthew Salganik’s lab, Princeton, and a poster on Causal Tree of Thoughts at ISCOL 2025.
- Jul–Oct 2025 Applied Scientist Intern at Amazon Science in Seattle (Sponsored Products). Built a DSPy-based retrieval-augmented generation system for sourcing sponsored products, and used prompt optimization to improve the relevance of sponsored ads on Amazon.com by about 5%.
- May 2025 Presented DEPTH at the RepL4NLP workshop at NAACL 2025, Albuquerque.
Papers
APPEAL: Attributing Persuasive Power to Expert-Specified Actions in LLMs
New Directions in Analyzing Text as Data (TADA) 2026 · UC Berkeley · Oral presentation
STATe-of-Thoughts showed that the sequence of rhetorical actions an LLM takes predicts how persuasive its argument is, but association alone does not tell us whether choosing a different action would have changed the outcome. APPEAL is a framework for estimating the causal effects of expert-specified steering actions on persuasiveness, treating each action as a treatment whose realization is text.
STATe-of-Thoughts: Structured Action Templates for Tree-of-Thoughts
Conference on Language Modeling (COLM) 2026 · San Francisco, CA
Also at the Workshop on Agent Behavior (WAB) at COLM 2026
Problem. Inference-time methods like Tree-of-Thoughts diversify reasoning trajectories through temperature sampling, but temperature cannot control how branches differ, nor produce traces that explain which reasoning choices drove output quality.
Method. STATe replaces sampling with discrete, interpretable textual interventions. A controller selects actions from a structured action space (e.g., which discourse relation or subtopic to develop next), converts each into a text prefix that steers the generator's continuation, and an evaluator scores candidates to guide beam search. Each surviving branch carries a logged sequence of actions.
Result. STATe substantially improves both the diversity and quality of generated outputs over temperature-based baselines. In argument generation, sequential models over logged action sequences prove highly predictive of output quality, showing that the ordering and composition of rhetorical choices carries meaningful signal.
DEPTH: Discourse Education through Pre-Training Hierarchically
Proc. 10th Workshop on Representation Learning for NLP (RepL4NLP) at NAACL 2025 · pp. 1–15 · Albuquerque, NM
Problem. T5 and its variants are pre-trained with span masking, which teaches token-level and semantic recovery but does not encourage the model to learn how sentences relate to one another structurally. Discourse understanding therefore depends entirely on task-specific supervision.
Method. DEPTH augments T5's span-masking objective with a discourse-oriented pre-training signal. The model is additionally trained to reconstruct the correct ordering of shuffled sentences—learning to reason about how ideas connect across a document, directly from unlabeled text and without changing the architecture or fine-tuning procedure.
Result. Pre-training with DEPTH improves data efficiency and downstream performance on tasks requiring discourse understanding. These gains also transfer favorably to other linguistic capabilities, suggesting that discourse-aware pre-training instills broadly useful representations rather than narrow task-specific ones.
Repositories
Inference-time compute with open-source LLMs: discrete textual interventions, structured action spaces, and tree search (DSPy and vLLM). Companion code for the STATe-of-Thoughts paper.
Code for DEPTH: Discourse Education through Pre-Training Hierarchically. A discourse-oriented pre-training objective for encoder-decoder language models.
DSPy-based Tree-of-Thoughts for persuasive argument generation and evaluation, with beam search and Monte Carlo tree search.
Contact
Technion – Israel Institute of Technology
Haifa, Israel