Call for Contributions

Call for Papers

Useful Documents

We are pleased to invite you to contribute to the 15th ACM Conference on Recommender Systems (RecSys 2021), the premier venue for research on the foundations and applications of recommendation technologies. The upcoming RecSys conference will be held from September 27th to October 1st 2021. The conference will be held in Amsterdam, Netherlands, with an inclusive format that accommodates remote attendance. The conference will continue RecSys’ practice of connecting the research and practitioner communities to exchange ideas, frame problems, and share solutions. All accepted papers will be published by ACM.

We invite submissions of original research on all aspects of recommender systems, including contributions to algorithms ranging from collaborative filtering to knowledge-based reasoning or deep learning, contributions to design ranging from studies of human preferences and decision-making to novel interaction design, contributions to systems including practical issues of scale and deployment, and contributions through applications that bring forward the lessons of innovative applications across various domains from e-commerce to education to social connections. We welcome new research on recommendation technologies coming from diverse communities ranging from psychology to mathematics. In particular, we care as much about the human and economic impact of these systems as we care about their underlying algorithms.

Topics of interest for RecSys 2021 include but are not limited to (alphabetically ordered):

  • Algorithm scalability, performance, and implementations
  • Bias, fairness, bubbles and ethics of recommender systems
  • Case studies of real-world implementations
  • Conversational and natural language recommender systems
  • Cross-domain recommendation
  • Economic models and consequences of recommender systems
  • Interfaces for recommender systems
  • Novel approaches to recommendation, including voice, VR/AR, etc.
  • Preference elicitation
  • Privacy and security
  • Socially- and context-aware recommender systems
  • Systems challenges such as scalability, data quality, and performance
  • User studies

Authors will be asked to assign a selection of predefined custom tags to describe their paper in the submission system. Tags can be assigned to indicate algorithms, interfaces, automated or user-centric evaluations, for example. Reviewers will also report their expertise over these tags, and the information will be used in review assignments.

Authors of main track research papers will also be asked to specify whether their work includes a component which is suitable for demonstration, which may be used to select some regular papers for additional presentation alongside other papers in the demo track. In case of acceptance in the main track, authors will be contacted by the Demos chairs to consider the inclusion of their work in the Demos track. Authors of rejected papers that have a demo component will have the opportunity to submit their demo as an independent submission, following the Demos call for participation.

We also point authors to the industry track for discussion of field experiences, deployments, users studies (etc.) that do not follow the framework of regular papers, or align with the reviewing guidelines below. A separate track is also included for late-breaking results papers; this track is intended for preliminary work, mainly focused on fostering discussions with other members of the RecSys community.

Reviewing Process

Reviewers will evaluate papers based on their significance, originality, rigor, and contribution to the field. In view of the RecSys conference goal of advancing the field, reviewers are also asked to consider the replicability of reported research. Replicability is to be assessed in the context of the work itself — we recognize that a set of customer interviews (for example) may not be shareable, but the interview scripts can be provided as may be response coding protocols. Sharing of data sets and code is encouraged, and authors presenting work that was tested on proprietary data may wish to include a secondary analysis on a public or shareable data set.
Papers that are out of scope, incomplete, or lack sufficient evidence to support the basic claims, may be rejected without full review.
This year we will include a short clarification phase, during which authors will be given a chance to submit a very brief response (i.e., up to 1000 characters) to address factual errors in reviews; clarifications may be considered during the discussion phase.

Submission Guidelines

Papers should report on substantial contributions of lasting value. The maximum length is 14 pages (excluding references) in the new single-column format. We encourage papers of any length up to 14 pages; reviewers will be asked to comment on whether the length is appropriate for the contribution. Shorter papers should generally report on advances that can be described, set into context, and evaluated concisely; they are not “work-in-progress” reports but rather complete reports on a smaller or simpler-to-describe but complete research work. Longer papers should reflect more complex innovations or studies and should have a thorough discussion of related work. Each accepted paper will be included in the conference proceedings and presented at the conference. We expect the review process to be highly selective: the acceptance rate for the past few years was about 20%.

All submissions and reviews will be handled electronically. Papers must be submitted to PCS by 23:59, AoE (Anywhere on Earth) on May 4th, 2021.


ACM’s archival publication format separates content from presentation in the Digital Library to enhance accessibility and improve the flexibility and resiliency of our publications. Following the ACM publication workflow, all authors should submit manuscripts for review in a single-column format. Instructions for Word and LaTeX authors are given below:

  • Microsoft Word: Write your paper using the Submission Template (Review Submission Format). Follow the embedded instructions to apply the paragraph styles to your various text elements. The text is in single-column format at this stage and no additional formatting is required at this point.
  • LaTeX: Please use the latest version of the Primary Article Template – LaTeX to create your submission. You must use the “manuscript” option with the \documentclass[manuscript]{acmart} command to generate the output in a single-column format which is required for review. Please see the LaTeX documentation and ACM’s LaTeX best practices guide for further instructions. To ensure 100% compatibility with The ACM Publishing System (TAPS), please restrict the use of packages to the whitelist of approved LaTeX packages.

A document with some frequently asked questions can be found here.

Authors are strongly encouraged to provide “alt text” (alternative text) for floats (images, tables, etc.) in their content so that readers with disabilities can be given descriptive information for these floats that are important to the work. The descriptive text will be displayed in place of a float if the float cannot be loaded. This benefits the author as well as it broadens the reader base for the author’s work. Moreover, the alt text provides in-depth float descriptions to search engine crawlers, which helps to properly index these floats. Additionally, authors should follow the ACM Accessibility Recommendations for Publishing in Color and SIG ACCESS guidelines on describing figures.

Should you have any questions or issues going through the instructions above, please contact support at for both LaTeX and Microsoft Word inquiries.
Accepted papers will be later submitted to ACM’s new production platform where authors will be able to review PDF and HTML output formats before publication.


The peer review process is double-blind (i.e., anonymized). This means that all submissions must not include information identifying the authors or their organization. Specifically, do not include the authors’ names and affiliations, refer to your previous work in the third person (e.g., “McAuley and Konstan (2021) recommended that RecSys submissions be anonymized by referring to the authors’ prior work in the third person.”), and avoid providing any other information that would allow reviewers to identify the authors, such as acknowledgments of individuals and funding sources. However, it is acceptable to explicitly refer in the paper to the companies or organizations that provided datasets, hosted experiments or deployed solutions if there is no implication that the authors are currently affiliated with the mentioned organization. We should note that reviewers are instructed not to search for tech reports, pre-prints, and other information about your research. Your responsibility is focused on making sure that the paper submission itself does not reveal your identity as author.

Ethical Review for Human-Subjects Research

ACM RecSys expects all authors to comply with ethical and regulatory guidelines associated with human subjects research, including research involving human participants and research using personally identifiable data. Papers reporting on such human subjects research must include a statement identifying any regulatory review the research is subject to (and identifying the form of approval provided), or explaining the lack of required review. Reviewers will be asked to consider whether the research was conducted in compliance with applicable ethical and regulatory guidelines.


Each paper should not be previously published or accepted to any peer-reviewed journal or conference, nor currently under review elsewhere (including as another paper submission for RecSys 2021). Papers published in workshop proceedings may only be submitted if the RecSys submission includes at least 30% new content; such papers must also reference the original workshop paper on the submission form (but not in the anonymized paper).


Plagiarized papers will not be accepted for RecSys 2021. Our committees will be checking the plagiarism level of all submitted papers to ensure content originality using an automated tool.

If you reuse non-novel text from a prior publication (e.g., the description of an algorithm or dataset), please be sure to cite the prior publication as the source of that text. If you have questions about reuse of text or simultaneous submission, please contact the program chairs at least one week prior to the submission deadline. Please refer to the ACM Publishing License Agreement and Authorship Policy for further details.

Papers violating any of the above guidelines are subject to rejection without review and cases may be referred to the ACM Publications Ethics and Plagiarism committee for further action where warranted.


Please take note that the official publication date is the date the proceedings are made available in the ACM Digital Library. This date may be up to two weeks prior to the first day of the conference. The official publication date affects the deadline for any patent filings related to published work.

SIGCHI Submitter Agreement

RecSys 2021 is a SIGCHI conference and making a submission to a SIGCHI conference is a serious matter. Submissions require time and effort by SIGCHI volunteers to organize and manage the reviewing process, and, if the submission is accepted, the publication and presentation process. Thus, anyone who submits to RecSys 2021 implicitly confirms the following statements:

  1. I confirm that this submission is the work of myself and my co-authors.
  2. I confirm that I or my co-authors hold copyright to the content, and have obtained appropriate permissions for any portions of the content that are copyrighted by others.
  3. I confirm that any research reported in this submission involving human subjects has gone through the appropriate approval process at my institution.
  4. I confirm that if this paper is accepted, I or one of my co-authors will present the paper at the conference, either in person or through a conference-designated remote presentation option. Papers that are not presented at the conference by an author may be removed from the proceedings at the discretion of the program chairs.
Important Dates
  • Abstract submission deadline: April 27th, 2021
  • Paper submission deadline: May 4th, 2021
  • Reviews released: June 22, 2021
  • Clarifications due: June 26, 2021
  • Author notification: July 6th, 2021
  • Camera-ready version deadline: July 27th, 2021

Deadlines refer to 23:59 (11:59pm) in the AoE (Anywhere on Earth) time zone.

Program Chairs
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