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 Principal 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.

Research and Academia

Our rules and delta system have allowed an environment to flourish which has been of interest to multiple researchers. Studies conducted using /r/changemyview can be found in the academic research section of our wiki. Perhaps most notably was the study by Tan, C. et al: “Winning Arguments: Interaction Dynamics and Persuasion Strategies in Good-faith Online Discussions“, which was featured in the You Are Not So Smart Podcast’s episode on Change My View, and reported on by various media outlets (such as Slate).

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), and 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 by 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.”

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, 2017: NPR’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.”

August 6, 2017: Elon Musk tweets about CMV.


December 31, 2017: The Washington Post – 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, 2018: WIRED – 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.”