Reddit’s AI hunt was much apt to propulsion formal, already-upvoted comments into its answers than comments pinch much markers of individual experience, according to a new preprint from researchers astatine the University of Illinois Urbana-Champaign.
The squad processed 10,000 questions done the characteristic 3 times and analyzed 30,000 answers by tracing them backmost done 14.68 cardinal comments. These questions originated from 20 proposal and support subreddits, truthful the findings screen that conception of Reddit, though the insubstantial has not undergone adjacent review.
Additionally, the answers carried almost nary of the first-person connection successful the comments they quoted, a alteration the authors opportunity transforms individual grounds into much wide advice.
Formal Language Was Tied To Higher Selection Odds
The researchers looked astatine comments that an reply quoted aliases listed arsenic a root and compared them to different comments successful the aforesaid chat that the reply passed over.
They recovered that the level of formality was the strongest connection predictor of which comments were chosen. Specifically, erstwhile a remark was 1 modular deviation much formal, it had 49% higher likelihood of being selected (odds ratio 1.488), pinch formality scored by a matter classifier. Additionally, comments that utilized words for illustration “should” and “must” besides had higher likelihood of being picked (1.070).
Comments pinch much markers of individual acquisition had little likelihood of action (0.789), and truthful did supportive connection (0.924). The insubstantial calls the first measurement experiential sound and scores it from features specified arsenic first-person pronouns and past tense.
Formality was besides associated pinch higher organization voting, while experiential sound was associated pinch little voting. After the researchers accounted for a comment’s score, position, and age, the associations shrank to 1.213 for formality and 0.860 for experiential voice.
The insubstantial doesn’t show that penning formally gets a remark selected. The authors write, “Our study is observational and should not beryllium interpreted causally.”
Comments That Were Already Visible Had An Edge
A comment’s ballot ranking wrong its thread showed the largest relation successful the action model, pinch a one-standard-deviation summation multiplying the likelihood of being chosen by 2.88.
The median selected remark was astatine the 91st percentile for people successful its thread, compared to the 45th percentile for comments not chosen. Of the selected comments, 92% were direct replies to the original post, which besides accounted for 53% of each comments. Additionally, selected comments appeared a median of 1.2 hours aft the post, whereas non-selected comments appeared aft a median of 5.9 hours.
A one-standard-deviation summation successful remark magnitude had an likelihood ratio of 1.79. Comments containing an outer nexus had an likelihood ratio of 2.25.
Comments pinch a people of zero aliases beneath made up 0.53% of selected comments and 5.1% of each comments collected.
The Written Answer Dropped Most First-Person Language
In an study of 1,000 of the queries, researchers compared Reddit’s quoted comments pinch the responses crafted astir them. Usage of words for illustration “I” and “my” decreased from 3.3% successful the quoted comments to 0.06% successful the answers.
The aforesaid queries were processed done GPT-4o-mini and GPT-5 via OpenAI’s API pinch web hunt enabled. Both models utilized little first-person connection than Reddit comments, pinch Reddit’s responses showing the largest reduction.
Overall, retired of 4,932 citations, 18 referenced Reddit crossed some models and hunt configurations. This information is based connected API calls for proposal queries, which differs from the setup utilized successful the ChatGPT app.
How The Audit Worked
The researchers utilized an LLM to rewrite existent posts from the 20 subreddits into short hunt queries. Ten are ample communities specified arsenic r/personalfinance and r/AskDocs, and 10 are smaller ones specified arsenic r/UKJobs and r/AusLegal.
The 3 runs were spaced astir 5 hours isolated truthful that differences would bespeak the strategy and not changes connected Reddit. When 2 runs pulled from the aforesaid root posts, the responses were almost identical. This shows that astir of the differences came from which posts the strategy chose to retrieve.
A emblematic reply utilized astir 7 different subreddits. The subreddit wherever the mobility was first asked contributed 17.7% of the retrieved posts successful the large-community group and 15.7% successful the small-community set. The authors mention they don’t spot a higher stock arsenic better.
The insubstantial refers to this characteristic arsenic Reddit Answers, which was its sanction erstwhile I first reported connected its launch successful December 2024. Reddit’s announcement page now shows an update from May 26, 2026, stating, “Reddit Answers is now merged into Reddit hunt for 1 unified hunt experience.”
The questions were created from posts dated done July 2026, truthful these runs happened aft that change, though the insubstantial doesn’t specify the postulation dates. Reddit’s Help page now describes the characteristic arsenic AI search, accessible done an Ask fastener successful the hunt bar.
Why This Matters
Reddit’s worth for assemblage investigation is group describing their ain acquisition pinch a merchandise aliases a problem. In these 20 communities, comments pinch much markers of that acquisition were little apt to scope the AI answer, and astir of the first-person wording was gone erstwhile they did.
Reddit CEO Steve Huffman told investors successful February that Reddit is peculiarly bully astatine questions wherever “the reply really is aggregate perspectives from tons of people.” This audit measured which of those perspectives reached the AI answer.
You’ll spot the root threads listed beneath each answer. Make judge to publication them first earlier including the summary successful your report.
Looking Ahead
The authors opportunity these action patterns whitethorn not transportation complete to different kinds of communities aliases to different AI hunt systems. I’ll update this communicative if a revised aliases peer-reviewed type changes the findings.
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