I am a graduate researcher in Natural Language Processing and Information Retrieval, currently pursuing my M.A.Sc. in Computer Engineering at the University of Guelph. I am working at the LS3 under the supervision of Dr. Ebrahim Bagheri and Dr. Fattane Zarrinkalam. Prior to that, I worked under the supervision of Dr. Behshid Behkamal at Ferdowsi University of Mashhad.
My research focuses on two main directions. The first is diffusion-based generative ranking, where I explore how denoising diffusion models can be adapted to improve ranking effectiveness in search and retrieval tasks. The second is enhancing the peer-review process, designing models and tools to evaluate and improve review quality, with the goal of making scholarly evaluation more consistent, transparent, and fair.
I have published multiple papers in venues such as SIGIR, ECIR, and CIKM, and combine my research with industry experience as a Data Scientist, where I design and deploy large-scale ranking systems, vector search infrastructures, and NLP pipelines. Currently, I am working at Reviewerly, developing and maintaining large-scale scholarly search and matching systems used in peer-review and grant assignment.
You can find my CV here.
🔥 News
- [2025/10] I attended the COLM 2025 conference in Montreal, Canada.
- [2025/08] Our paper "Query Performance Prediction Using Neural Query Space Proximity" got accepted at TIST.
- [2025/08] Our paper "RottenReviews: Benchmarking Review Quality with Human and LLM-Based Judgments" got accepted at the CIKM 2025.
- [2025/08] Our proposal for a presentation in the Industry Day talks, "Building Trustworthy Peer Review Quality Assessment Systems", got accepted at CIKM 2025.
- [2025/08] I attended the KDD 2025 conference in Toronto, Canada. I served as a student volunteer for the first time and loved the experience!
- [2025/07] I am co-organizing the ProActLLM workshop at CIKM 2025 which explores proactive and adaptive behaviors of LLMs. Submit your work and be part of the conversation!
- [2025/04] I attended the ECIR 2025 conference in Lucca, Italy.
- [2025/04] Our paper "Reinforcement Learning for Effective Few-Shot Ranking" got accepted at SIGIR 2025.
- [2025/03] Our paper "Estimating Query Performance Through Rich Contextualized Query Representations" got accepted for oral presentation at the QPP++ workshop.
- [2025/03] I won the Braithwaite Conference Travel Grant to attend the ECIR 2025 conference.
- [2024/12] Our paper "exHarmony: Authorship and Citations for Benchmarking the Reviewer Assignment Problem" got accepted at ECIR 2025.
- [2024/12] I presented "It Takes a Team to Triumph: Collaborative Expert Finding in Community QA Networks" paper at the SIGIR-AP 2024 conference.
- [2024/12] I attended the SIGIR-AP 2024 conference in Tokyo, Japan.
- [2024/12] I attended the ACML 2024 conference in Hanoi, Vietnam.
- [2024/11] I won the Braithwaite Conference Travel Grant to attend the SIGIR-AP 2024 conference.
- [2024/11] I won the Braithwaite Conference Travel Grant to attend the ACML 2024 conference.
- [2024/09] Our paper "Gender Disentangled Representation Learning in Neural Rankers" got accepted at Machine Learning Journal (MLJ).
- [2025/08] Our proposal for a presentation in the Industry Day talks, "Reviewerly: Modeling the Reviewer Assignment Task as an Information Retrieval Problem", got accepted at CIKM 2024.
- [2024/05] I attended the Canadian AI 2024 conference in Guelph, Canada.
- [2024/05] I presented Reviewerly at the First OpenAlex User Conference.
- [2024/03] I attended the ECIR 2024 conference in Glasgow, Scotland. It marked my introduction to the research community and my first time engaging with key figures in the field!
- [2024/11] I won the Braithwaite Conference Travel Grant to attend the ECIR 2024 conference.
- [2023/12] My first paper got accepted! Our paper "Estimating Query Performance Through Rich Contextualized Query Representations" got accepted at ECIR 2024.
- [2023/10] I won the CEPS Dean’s Graduate Entrance Scholarships for the Fall 2023 semester.
- [2023/09] I started my M.A.Sc. in Computer Engineering at the University of Guelph.
- [2023/04] I won the Entrance Award in Recognition of Student Excellence in the College of Engineering and Physical Sciences at the University of Guelph.
- [2023/07] I graduated with a B.Sc. in Computer Engineering from Ferdowsi University of Mashhad.
📝 Publications
- Query Performance Prediction Using Neural Query Space Proximity [pdf] [code]
Amin Bigdeli, Sajad Ebrahimi, Negar Arabzadeh, Sara Salamat, Shirin SeyedSalehi, Maryam Khodabakhsh, Fattane Zarrinkalam, Ebrahim Bagheri
ACM Transactions on Intelligent Systems and Technology (TIST) - RottenReviews: Benchmarking Review Quality with Human and LLM-Based Judgments [pdf] [code] [data]
Sajad Ebrahimi, Soroush Sadeghian, Ali Ghorbanpour, Negar Arabzadeh, Sara Salamat, Muhan Li, Hai Son Le, Mahdi Bashari and Ebrahim Bagheri
CIKM 2025: 34th ACM International Conference on Information and Knowledge Management - exHarmony: Authorship and Citations for Benchmarking the Reviewer Assignment Problem [pdf] [code] [data]
Sajad Ebrahimi*, Sara Salamat*, Negar Arabzadeh, Mahdi Bashari, Ebrahim Bagheri
ECIR 2025: 47th European Conference on Information Retrieval - Reinforcement Learning for Effective Few-Shot Ranking [pdf]
Shiva Soleimany, Sajad Ebrahimi, Shirin SeyedSalehi, Fattane Zarrinkalam, Ebrahim Bagheri
SIGIR 2025: 48th International ACM SIGIR Conference on Research and Development in Information Retrieval - Gender Disentangled Representation Learning in Neural Rankers [pdf] [code]
Shirin SeyedSalehi, Sara Salamat, Negar Arabzadeh, Sajad Ebrahimi, Morteza Zihayat, Ebrahim Bagheri
Machine Learning Journal (MLJ) - Reviewerly: Modeling the Reviewer Assignment Task as an Information Retrieval Problem [pdf]
Negar Arabzadeh, Sajad Ebrahimi, Sara Salamat, Mahdi Bashari, Ebrahim Bagheri
Industry Day at CIKM 2024: 33rd ACM International Conference on Information and Knowledge Management - Estimating Query Performance Through Rich Contextualized Query Representations [pdf] [poster] [slides] [code]
Sajad Ebrahimi, Maryam Khodabakhsh, Negar Arabzadeh, Ebrahim Bagheri
ECIR 2024: 46th European Conference on Information Retrieval
💬 Talks
- Estimating Query Performance Through Rich Contextualized Query Representations [slides]
QPP++ 2025, April 2025 - It Takes a Team to Triumph: Collaborative Expert Finding in
Community QA Networks [slides]
SIGIR-AP’24, December 2024 - Reviewerly: A High Quality Peer Reviewer Suggestion Application [recording] [slides]
2024 OpenAlex Virtual User Conference, May 2024 - Introduction to Neural Information Retrieval [code] [slides]
Special Topics in Information Retrieval-University of Guelph, November 2023