Foto: Miguel Henriques

“The biggest talk scientists ever give”

Reddit coined itself “the front page of the Internet”. The platform allows scientists to address a large audience, explain the methods of science, and dispel common myths about their research. An interview with a former r/science moderator and a researcher about the platform’s role in science communication.

Ms. Below, Ms. Hara, why should scientists participate on Reddit? 

Jennifer Piper Below is an Associate Professor of Medicine in the Vanderbilt Genetics Institute at Vanderbilt University Medical Center. She holds a PhD in Human Genetics. Below is a former head moderators on Reddit’s r/science community. Photo: private

Jennifer Piper Below: An AMA on Reddit is basically the biggest scientific talk scientists ever give. Usually, they have to rely on intermediaries like the media to shape how the public perceives their work. Reddit is a chance to cut out the middleman and to use your own words with lay audiences to express the nuances and importance of your area of expertise. There’s no other science communication platform that can achieve this kind of direct communication on such a massive scale. 

Noriko Hara: Twitter and Facebook are more for top-down communication or used by scientists to talk to their peers. Our research shows that interaction on Reddit AMA is generally coming from the public. They ask questions and cast up-votes for comments that a lot of people are interested in. It is really amazing how well moderators are filtering unrelated comments or possible trolling messages so that a scientist can have a good experience when sharing their research. They verify users as well.

What characterizes the platform Reddit?

Noriko Hara is department chair and professor of information science in the Luddy School of Informatics, Computing and Engineering at Indiana University, Bloomington. Her current research focuses on public engagement with science on social media. Photo: private

Below: Reddit has been coined “the front page of the Internet”. It’s a platform for social communication. One of the unique features of Reddit is that it is subdivided into different topic-specific domains called “subreddits” or “communities”. Users choose them based on their specific interests. Individuals can post to a particular subreddit and others can engage with it. Each subreddit is run by a group of volunteer moderators. They decide on the specific rules of engagement. A lot of spaces on Reddit are like the Wild West… anything goes, others must conform to pretty high standards, for example, requirments that post be highly topic-specific. As a result of moderation, Reddit as a social media platform can be highly curated. 

Ms. Below, you were once a head moderator at r/science. How does this verification process on Reddit work?

Below: Readers of r/science and r/askscience can communicate directly with moderators and provide evidence of their expertise. The moderators then assign these readers a little label on their user name that says “Ph.D. in Biochemistry” or “Masters of Science in Computational Genetics”. These allow other people to know what your background and level of expertise are when you are engaging on these platforms. It can really help shape the dialogue. But only a relatively small proportion of the readership has actually gone through the process to get verified. Both r/askscience and r/science aggressively enforce rules about staying on topic and not asking questions that are personal in nature or inappropriate, and verified users are extremely important in helping set the level of discourse.

Who is hosting science communication sessions on Reddit?

Below: “Ask Me Anything”s or “AMAs” happen all across Reddit. There are even whole subreddits devoted to AMAs, like r/IAmA which is probably the space where they happen most frequently and with the largest readership. But they also happen on topic-specific communities for example, r/askscience often hosts AMAs today on science-related topics. Some subreddits allow guests to just sign up, others are invite-only, or are more rigorous in selecting their guests. Together with Nate Allen, another now-retired head moderator of r/science, I led the organization of r/science AMAs. The subreddit hosted AMA daily for nearly a decade but the program ended because of changes to the Reddit algorithm. 


Reddit – short for “read and edit” – is a news aggregation social media platform. It is subdivided into topic-specific forums, so-called subreddits, that attract their unique communities. Users can decide which posts are more or less relevant by up- or downvoting them. Some subreddits host AMA sessions: A person comes on and answers questions from the community. A prominent subreddit that offers this feature is r/IAmA. The science-related subreddit r/science used to host AMAs as well until an algorithmic change caused the organizers to cease them.

How did the algorithmic change affect the AMA sessions?

Below: When I helped run the subreddit r/science, we were approaching the mid-twenties of millions of subscribed readers. By now, it is probably closer to 30 million members. In the heyday of our AMA program, we hosted one or two AMAs per day. Prior to the algorithmic change, we had great engagement on these posts. We’d get around three hundred thousand to one million impressions on any given discussion, and people would typically have left hundreds to thousands of comments. Then, fairly suddenly, our AMAs started getting very little attention. When a prominent person like President Biden comes on and does an AMA that’s still going to attract a whole lot of people. But with a scientist who’s hardly a household name the algorithmic changes ended up depressing the visibility of our r/science AMAs. There are no more AMAs that happen on r/science, but you can still find them on another subreddit called r/askscience.

The algorithm probably affected other subreddits as well. Were there any user movements or demands to change it back again in order to regain more visibility?

„When I helped run the subreddit r/science, we were approaching the mid-twenties of millions of subscribed readers.“ Jennifer Piper Below
Below: The r/science moderation team lobbyied for years on behalf of the science communication community. We told Reddit administrators how efficacious it was in giving real, valuable, accurate scientific information to Reddit readers. Reddit posts never disappear, so our AMAs created a permanent, publicly available record on the Internet of a scientist’s description of their work. Where else does an average person have the opportunity to directly engage with global experts about their cutting-edge research on topics like climate change, chemistry, medicine, space, or social science? About the nuances of what is known? What their daily work is like? AMAs are a rare and precious opportunity to democratize direct access to scientists.

The Reddit algorithm used to be open-source, but they took it private. Since then, they enforced a policy of not discussing changes. Moderators don’t actually know when admins are rolling out changes that might affect the visibility of posts.

In your experience, who is participating in discussions about science on Reddit and why?

Below: Our audience at r/science was in large parts – like the overall demographic of Reddit – a young, white, college-age, male population. But Reddit has 430 million users, which means that other groups represented by smaller percentages are still very large numbers of people. Reddit is a platform that allows for anonymity. There’s no requirement for people to link their usernames to any photo, name, or identity, so it is impossible to know exactly which demographics are represented in those that were commenting, upvoting posts, or participating in our discussions and AMAs.

Ms. Hara, you analyzed AMA sessions that took place on Reddit. What methods did you use and what was your research aim? 

„Every scientist that comes on to this AMA session has specific expectations and a unique style.“ Noriko Hara
Hara: I surveyed scientists who had engaged in r/science AMA sessions. I wanted to explore the kind of experiences they had on Reddit. Most scientists found participating in an AMA session interesting and rewarding, especially when collaborating with other scientists. As Piper said, they reached large audiences. I also noticed that some professional organizations used AMAs on Reddit. For example, each Wednesday editorial staff of the journals of the PLOS family hand-selected papers that have recently been published and they thought would be of public interest. They invited the authors to participate in a related AMA session on r/science, which immediately gave them a broad platform for discussion of their work.

Which topics are usually discussed on science-related subreddits? 

Hara: In my research, I also looked at popular topics. Obviously, there are a variety of topics discussed on Reddit, including social science. But certain disciplines like maths, physics, or applied areas like health and medicine got more user engagement than others.

Below: We had tremendous success across a vast array of science-related topics. Scientists who come on Reddit and draw on their whole experience as researchers, and we hosted great discussions about science careers. I loved that we could have huge engagement on crucial details in research- inherent sample biases in studies, or people really getting into the weeds of statistical approaches that were used in papers. Researchers often would discuss the broader consequences of their work, for example, the potential impact of a genetic finding in medicine. Topics with relevance to readers’ lives generated great discussions. Many of our conversations were about dispelling myths. Over the years, we had hundreds of climate scientists on r/science to discuss their work. Especially in areas of science that are considered controversial, Reddit offers a chance for the researchers themselves to have a platform to address those controversies directly with people that might hold dear false information about that science. And, like in so many online spaces, we found that controversy absolutely drives engagement. 

Ms. Hara, you also looked into how many questions were answered in on AMA session. Tell us more about it.

Hara: On average, about 50 percent of the questions were answered by the participating scientists. The rate was especially high when the questions were short. One AMA session that we surveyed had only a 20 percent response rate. It was the result of the scientist crafting very detailed responses. I don’t know what the best approach is. Every scientist that comes on to this AMA session has specific expectations and a unique style. Some people like to elaborate. Others just want to give a simple answer but manage to go through the list of questions. With different sessions, the audience will get different styles of answers. To put the results into context: We did not do a systemic review of all AMA sessions. Our sample only contained posts that got 200 or 300 responses.

„Only through the work of a team of thousands of moderators were we able to cultivate a good experience for the guests and the readers.“ Jennifer Piper Below
Below: In our sessions, we told the scientists to respond in their own style. We neither dictated the length of their answer nor gave them instructions on how many questions they needed to respond to. We just asked them to spend one or two hours minimum engaging with questions on the post. That probably explains some of the differences in response rates.

What aspects of Reddit need further research?

Hara: It would be nice to gain moderators’ perspectives and ask what they are doing. Because their work was a big part of why the scientists were having a great time during the AMAs. Sometimes scientists might not feel comfortable communicating with the public. Because the r/science AMA sessions were so well taken care of by moderators, they were happy to engage.  

Did it also translate into a more moderate tone of the discussions?

Hara: At the time of the study, the tone was definitely very civil and collegial. We looked for social cues, for example, aggressive messages in comparison to polite ones. We found the community to be very healthy. There wasn’t too much trolling or aggressive behavior going on. The reason why Reddit attracts so many people is that it has a kind of playfulness. The participating scientists seemed to have understood the protocol and culture of Reddit and went with it. But what was happening behind the scene – the moderators filtering the messages – is very important for a healthy environment for conversation.

„The reason why Reddit attracts so many people is that it has a kind of playfulness.“ Noriko Hara
Below: On the worst threads, moderators remove 90 percent or more of the comments. When Noriko’s paper came out, I reached out to her to say: Your work presents us as healthy, but it ignores all the removed content. That is where all the vitriol, hostility, trolling, gaslighting, sexism, and racism are happening. There is zero-tolerance for this on r/science and r/askscience. Only through the work of a team of thousands of moderators were we able to cultivate a good experience for the guests and the readers. If you only look at the posts that are shown, you get an extremely curated view. 

What role might Reddit play in science communication in the future?

Below: To some extent, scientists are still able to use r/askscience to continue to engage directly with the interested public, I’m so grateful and proud of the moderators of r/askscience for their continued work. But, I’m not gonna lie to you and tell you that I am wildly optimistic about the use and reach of AMAs on Reddit for science outreach into the long-term future. Yet, I am really optimistic that there is a thirst for this kind of content, which we saw before the algorithm changes. When people see scientific content in their feeds they upvote it, they share it, they comment on it. That shows the hunger of the general population to understand what’s happening in cutting edge research. We just need to be able to get it in front of them.

Hara: I agree with Piper that this type of interaction is very important for the public but I am also not sure whether Reddit is the right platform. I have been thinking a lot about where we are going in the future but I think it is not a good idea to build a separate platform and then try to invite people to do the same thing over there. I think we have to go where the public is. Visionaries like Piper and Nathan developed  r/science AMA as a venue for science communication. Now we have to figure out: What’s the next place where that kind of discourse is happening? I noticed that when r/science stopped to host the AMAs the number of subscriptions on r/askscience went up. People find these places.