This page will detail various aspects of the ‘Change My View’ subreddit (

Top posts from Jan 2017 – Jan 2018.


The basic idea behind /r/changemyview (CMV) is to be a place for people to present views they accept may be flawed, in order to hear from those who disagree, with the aim of gaining perspective and understanding. From this comes an important distinction: CMV isn’t a debate forum, but one for discussion and conversation. This might sound pedantic at first, but the difference in mentality can be significant. A debate is like a competition, where the focus is on ‘winning’ or appealing to the crowd. A conversation is more about asking questions and seeking to understand where other people are coming from.

CMV aims to discourage a growing problem in today’s society where people relentlessly argue over something at a surface level, without appreciating or attempting to understand the underlying reasons for beliefs. This approach rarely changes views.

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In order to facilitate a better kind of discussion, we have an actively moderated set of rules. These can be found on the sidebar of the subreddit (strip of information to the right), or in full detail in the rules section of our wiki. As an overview, we split rules into two categories: submission rules and comment rules.

The submission rules provide a strong foundation for discussion.

Submission rules, as shown on the sidebar of r/changemyview.

While many people hold the same general opinion on something – i.e. the title of their posts might be the same – each case could have its own unique ‘reasoning path’. Since our views are the result of personal experience, upbringing, and other background factors – laying these out in the original post helps the commenters to adjust their approach.

This is partly why it’s so important that the author of the post (OP) actually believes the view, and isn’t posting on behalf of someone else or playing devil’s advocate – it’s one thing to put yourself in someone else’s shoes, and another entirely to invent a personal history.

The subreddit’s name, Change My View, isn’t a dare or challenge the OP makes to commenters, but a request. It’s therefore vital that the OP demonstrates an openness to such change occurring. To fully appreciate this you must understand what we mean by ‘change’. Some people get stuck on the definition of ‘change’ to mean ‘reversal’ or ‘opposite’ of the view, as if we require you to strongly dislike what you believe. But we actually consider a change of view to mean gained perspective of any kind, and this can even include keeping the same general opinion while understanding, appreciating, or empathising with other views a bit better. Striving to avoid such changes from the outset therefore creates a weak foundation.

The submission title can make a big difference to which commenters choose to enter the discussion and the mindset they have. A sensationalised, vague, or misleading title can cause all sorts of problems. While this is more on the administrative side of things, even the presence of “CMV:” at the start of the title changes the entire tone of the post.

While we make no restrictions to topics based on popularity or perceived offensiveness, we do have a few types of post that we consider unsuitable for CMV. ‘Neutral stances’, for example. It’s very hard for this to lead anywhere productive if the discussion is essentially a free-for-all, and it’s harder to moderate too.

Lastly, we ask that the OP chooses to create the post at a time that allows them to actually participate in the discussion. It is intended to be a conversation after all, and while we don’t require them to sit by their computer for the first three hours, we ask that there is at least some proof of interest during this time.

The comment rules ensure the discussion that builds on this foundation is civil and productive.

Comment rules, as shown on the sidebar of r/changemyview.

For OPs, CMV is an anti-echo chamber by design. We prohibit users from simply agreeing with OP in direct response. This has two key benefits: It deters those who might just want to be reassured or agreed with, and it provides unadulterated insight for those who genuinely wish to engage with counter-arguments.

But it’s not enough that the opportunity to engage is there. For the discussion to go anywhere productive, all participants in the conversation must be respectful and civil. As moderators, we’ve had to deal with many cases where an ad hominem attack (insulting the person’s character instead of addressing their argument) has derailed the conversation and reduced the chances of a view-change taking place, often igniting retaliation.

While rudeness and hostility is usually quite obvious, we also ask that users adhere to the Principle of Charity and assume that others are participating in good-faith, without deception or malicious intent. While it’s possible this isn’t the case, we ask that such concerns are raised privately with the moderators in order to remove the possibility of damage from a false accusation.

Those who are acting in bad faith – as opposed to expressing a misguided view sincerely held – can’t be considered meaningful contributors to the conversation and as such their comments will be removed. Innocent oversight of our rules resulting in ‘low-effort’ comments that serve no purpose will be removed under the same umbrella.

If, as a submitter or commenter, you do gain perspective of some kind – we consider this a change of view. To acknowledge this, we encourage users to award a ‘delta’ (∆) to the user who changed their view.

The Delta System

It can be very easy for us to absorb and move on from a view-change without fully acknowledging it, leading to the self-image that we’re usually right instead of a work in progress. The delta system exists to encourage people to take a moment to acknowledge the change, and also the person who made it happen.

Instructions on how to award a delta from the CMV sidebar.

Since the uppercase delta (∆) is used in mathematics to represent change, we decided to use it in CMV for this purpose too. Any user should reply to a comment that changed their view with a delta symbol and an explanation of the change.

Like I mentioned before, people often mistakenly think the delta is reserved for complete reversals, or ‘180’ changes to a view. But we celebrate any level of gained understanding.

DeltaBot scans every comment made in /r/changemyview to find deltas, and when it does, it performs a series of tasks. Full details can be found in the delta section of our wiki.

While most of this revolves around those who earned a delta, it ends up being beneficial for everyone involved. The incentive of earning a delta by changing someone else’s view encourages people to learn from those who are more successful at doing so. We have seen that rudeness and hostility is less likely to change someone’s view, and just copy/pasting a ‘wall of sources’ without any interaction isn’t ideal either, so if these people want to earn deltas, they will have to learn as they go.

One thing DeltaBot does is add or increase a delta score next to the recipient’s username, using reddit’s ‘flair’ feature. In the following image you can see /u/PianoConcertoNo2 earned one delta, which is shown next to their username.

Taken from “CMV: Professors should not be able to teach exclusively or mainly from their own writings.”

In DeltaBot’s confirmation comment, you can see the recipient’s total delta score in parentheses. Clicking this link will take you to their personal delta history page, created and maintained in our wiki by DeltaBot. Anybody’s personal wiki page can be found at It includes two tables of links for deltas received and deltas given.

Example of a delta history wiki page (source).

The bot also maintains our ‘deltaboards’, with the sidebar listing those who have earned the most deltas in the current month. Daily, weekly, monthly, and yearly deltaboards can be found in the wiki.

Monthly deltaboard from January 2018.

DeltaBot also comments in posts where the OP has awarded deltas with a link to the corresponding post in /r/DeltaLog, which is intended to be a browseable archive of delta-earning comments.

This benefits people who open the post after there is already many comments and want to jump straight to reading those that were effective.  It also allows us to provide a popular topics search function of /r/DeltaLog in the top of CMV’s sidebar, for those who wish to read through old posts to see if their exact view has been covered already.

Academic Research

Our rules and delta system have allowed an environment to flourish which has been of interest to multiple researchers.

Some notable papers are listed below the following line in chronological order. The first – a study by Tan, C. et al – was featured in You Are Not So Smart’s episode on Change My View, and covered by various media outlets. A full list of the research papers that mention or focus on /r/changemyview can be found in our wiki.

CMV has also partnered with the research project “What Are They Thinking?” (currently under development), where OPs of productive posts are encouraged to write a summary article. More information can be found at

Tan, C., Niculae, V., Danescu-Niculescu-Mizil, C. & Lee, L. (2016) Winning Arguments: Interaction Dynamics and Persuasion Strategies in Good-faith Online Discussions, Proceedings of the 25th International World Wide Web Conference (WWW’2016).

Changing someone’s opinion is arguably one of the most important challenges of social interaction. The underlying process proves difficult to study: it is hard to know how someone’s opinions are formed and whether and how someone’s views shift. Fortunately, ChangeMyView, an active community on Reddit, provides a platform where users present their own opinions and reasoning, invite others to contest them, and acknowledge when the ensuing discussions change their original views. In this work, we study these interactions to understand the mechanisms behind persuasion.

Wei, Z., Liu, Y. & Li, Y. (2016) Is This Post Persuasive? Ranking Argumentative Comments in the Online Forum, The 54th Annual Meeting of Association for Computational Linguistics, Vol. 2 (Short Papers), pp. 195-200.

In this paper we study how to identify persuasive posts in the online forum discussions, using data from Change My View sub-Reddit. Our analysis confirms that the users’ voting score for a comment is highly correlated with its metadata information such as published time and author reputation. In this work, we propose and evaluate other features to rank comments for their persuasive scores, including textual information in the comments and social interaction related features. Our experiments show that the surface textual features do not perform well compared to the argumentation based features, and the social interaction based features are effective especially when more users participate in the discussion.

Hidey, C., Musi, E., Hwang, A., Muresan, S. & McKeown, K. (2017) Analyzing the Semantic Types of Claims and Premises in an Online Persuasive Forum, In Proceedings of the 4th Workshop on Argument Mining. EMNLP.

Argumentative text has been analyzed both theoretically and computationally in terms of argumentative structure that consists of argument components (e.g., claims, premises) and their argumentative relations (e.g., support, attack). Less emphasis has been placed on analyzing the semantic types of argument components. We propose a two-tiered annotation scheme to label claims and premises and their semantic types in an online persuasive forum, Change My View, with the long-term goal of understanding what makes a message persuasive. Premises are annotated with the three types of persuasive modes: ethos, logos, pathos, while claims are labeled as interpretation, evaluation, agreement, or disagreement, the latter two designed to account for the dialogical nature of our corpus. We aim to answer three questions: 1) can humans reliably annotate the semantic types of argument components? 2) are types of premises/claims positioned in recurrent orders? and 3) are certain types of claims and/or premises more likely to appear in persuasive messages than in nonpersuasive messages?

Jhaver, S., Vora, P. & Bruckman, A. (2017) Designing for Civil Conversations: Lessons Learned from ChangeMyView, GVU Center Technical Reports.

Research has shown that people all over the world, and particularly Americans, are divided over many issues – from immigration and gun control to economic and foreign policy. Information bubbles further contribute to these divisions: People prefer to consume content they feel familiar with and see views they agree with. Yet, pluralism and viewpoint diversity are necessary for a well-functioning democracy. In this paper, we explore how we can design interfaces that dial down partisan antipathy and allow users with opposing viewpoints to understand one another. We study ChangeMyView (CMV) subreddit, a community that encourages users to change their opinion by inviting reasoned counterarguments from other members. We use interviews with 15 CMV members to gain insights about the design mechanisms and social norms that allow this community to function well. We also explore how we can replicate such civil interactions between users with different ideologies on other platforms.

Educational Use

Some University and College educators have taken an interest in CMV, with the following examples using it for assignments:

  • Drexel University (Philosophy 105)
  • Washtenaw Community College (English 111)
  • University of Denver (Theories of Writing)
  • Touro College (Advanced Expository Writing)
  • San Jose City College (English)
  • Eastern Illinois University (Argumentation and Critical Thinking).

Teachers/professors interested in using CMV are encouraged to message the moderators in advance and hand out this guide to their students.

Some teachers have taken inspiration for the classroom without using the subreddit directly:


Media Coverage

CMV has been covered/mentioned in various media outlets. Here are some notable examples, in chronological order:

October 9, 2016‘You Are Not So Smart’ Podcast, 086 – Change My View. In this episode you’ll hear from the co-founder of Reddit, the moderators of Change My View, and the scientists studying how people argue on the internet as we explore what it takes to change people’s perspective and whether the future of our online lives is ever thicker filter bubbles or the increasingly effective process of whittling away our worst ideas.

May 3, 2017: Cory Doctorow talks about CMV during a technical problem with his live-streamed Edward Snowden interview. (Starts at 1:02:14) There’s a subreddit called Change My Mind [sic] that’s devoted to people who are honestly interested in having their minds changed, and they deploy a lot of the strategies of the so-called rationalist movement […] And that good will and willingness to spend the time is a way that minds genuinely change, and I’ve seen it work. 

June 23, 2017: NPR’s Planet Money, Episode 780 – On Second Thought. We bring you an economist who set out to test a core political conviction. We talk to a novelist who came face-to-face with the shaky foundations of his ideas about copyright. And we journey to a world where thousands of people are rethinking their opinions, and people who make constructive arguments are stars.

June 29, 2017NPR’s All Things Considered – Change My View On Reddit Helps People Challenge Their Own Opinions. The founder talks about the surprising rules he had to implement in order to make the space work, and a researcher tells us who discovered a kind of agree-to-disagree inflection point by studying the group.

July 26, 2017: Tristan Harris mentions CMV in WIRED interview with Nicholas ThompsonSomeone pointed both Sam [Harris] and I after that to a channel on Reddit called “changemyview.” It’s basically a place where people post questions, and the premise is, “I want you to change my mind about this thing.” And it’s really really good. And that would be more time well spent for people.

August 6, 2017Elon Musk tweets about CMV.


December 31, 2017The Washington Post, Avi Selk – Here’s proof that not everything was terrible on the Internet in 2017. (Third story down) Far from turning into a niche forum, Change My View now boasts half a million subscribers, and this year it’s been the subject of studies at Columbia University and the Georgia Institute for Technology, as academics try to figure out its secret.

January 16, 2018WIRED, Virginia Heffernan – Our Best Hope for Civil Discourse Online is on … Reddit. Submitters are not supposed to look for fights on Change My View; that’s for … everywhere else on the internet. Instead CMV posters foreground their flexibility—and maybe some insecurity, which brings with it a poignant willingness to be transformed.

January 16, 2018: Boing Boing, Cory Doctorow – Change My View: the subreddit for people willing to have their most cherished beliefs challengedI have lurked there many times, and I find it remarkable indeed; and Virginia Heffernan’s Wired profile of the forum and its founder and moderator Kal Turnbull, who founded the forum in 2013 when he was 18, gives an excellent sense of the near-miracle of honest, substantive dialog over subjects of enormous passion and import. Now, that said, I have a couple of mild caveats…

February 25, 2018The Observer (UK Newspaper) & The Guardian ‘Opinions’, Tim Adams – On the other hand… Twitter, Facebook, even reading newspapers didn’t feel like a solution, he explains to me. “I guess what I was looking for was a place where you might offer an opinion up almost in a catered way” – as if to address a very precise and pressing need – “and people would come in and say, OK you think this for these reasons let’s see if we can pull that apart and change your view.”

March 11, 2018: ‘Behavioral Grooves’ Podcast, Episode 10 – Changing the World One View at a TimeIn this interview, Kal shares his discoveries with a community of over 520,000 people willing to engage in civil discourse about views they currently don’t buy into.

April 15, 2018: Rationally Speaking Podcast 206 – Kal Turnbull on “Change My View”When people argue on the internet, you never expect anyone to actually say “You know what, that’s a good point, you’ve changed my view somewhat.” But Change My View, a fast-growing subreddit founded by Kal Turnbull, is an exception to the rule. Julia [Galef] and Kal discuss the culture of Change My View, what makes it such an oasis for reasonable discussion on the Internet, and what we’ve learned about what motivates people to change their minds or not.