RealCompanion: Benchmarking Human Understanding from Reasoning over Longitudinal Real-World Conversations
Arman Behnam, Sunglyoung Kim, Liangwei Yang
Quis Lab · Independent Researcher
Published October 1, 2026 · on the feed October 5, 2026 · ▲ 275 · arXiv 2610.01780
The abstract
A companion that talks with a person for months should come to understand them. It should remember what they said, infer who they are, and know when the past bears on the message in front of it. Testing this requires a real person's record, and such records are private, so benchmarks generate the person and the questions and settle in advance what matters. We release \bench, ten real relationships with an AI companion: 27,218 messages over up to 120 days, released as the conversation and four files derived from it, a profile, a persona, a chat ground truth and a question set, each citing the messages it rests on. Every chat label carries the reasoning trace that produced it, checked stage by stage against the conversation. Three findings follow. First, the past is rarely needed and far away. Pooled measures mislead: a recency window finds the required message for 95.9\% of probes and 2.2\% of those that need memory, and at the natural rate 96\% of the gain from supplying recorded evidence comes from messages that need none. Second, no detector we tried can tell when memory is needed on real messages, authored questions over the same histories leak the cue, and labeling the same messages as memories raises their use by ten to fourteen points. Third, three agent systems reconstruct the persona with the same F1 at a 31-fold difference in cost.
The Brief
2:42A short podcast summary of the paper. Written and voiced by AI.
Transcript
RealCompanion. Benchmarking Human Understanding from Reasoning over Longitudinal Real-World Conversations. By Arman Behnam and two others, from Quis Lab and Independent Researcher. Published on the first of October. No code repository is linked to it.
A companion that talks with a person for months should come to understand them. It should remember what they said, infer who they are, and know when the past bears on the message in front of it. Testing that requires a real person's record, and such records are private. Benchmarks therefore generate the person and the questions, and in doing so they settle in advance what matters. A generated history contains exactly the facts its author planted, and its questions point straight at them. That is the gap: a record built that way can only test the assumptions it was built on, not whether they hold in a real relationship.
The three abilities in that description are what gets tested. Remembering what was said. Inferring who the person is, down to reconstructing a persona. And knowing when an earlier message actually bears on the current one, which is the question of when memory is needed at all.
The release is ten real relationships with an AI companion: twenty-seven thousand two hundred and eighteen messages, over up to one hundred and twenty days. It ships as the conversation itself plus four files derived from it. Those are a profile, a persona, a chat ground truth, and a question set, and each of them cites the messages it rests on. Every chat label also carries the reasoning trace that produced it, checked stage by stage against the conversation. The citations and traces are what keep a real record usable as a benchmark: any answer can be followed back to the exact messages that justify it.
Three findings follow. First, the past is rarely needed, and when it is, it is far away. Pooled measures mislead here. A recency window finds the required message for ninety-five point nine percent of probes, but for only two point two percent of the probes that need memory. At the natural rate, ninety-six percent of the gain from supplying recorded evidence comes from messages that need none.
Second, no detector the authors tried can tell when memory is needed on real messages. Questions authored over the same histories leak the cue, and labeling the same messages as memories raises their use by ten to fourteen points. The cue, in other words, can come from how a question is asked or how a message is labeled, rather than from the conversation. Third, three agent systems reconstruct the persona with the same F1, at a thirty-one-fold difference in cost. Spending more did not buy a better picture of the person.
Real histories rearrange what looks easy and what looks hard. A generated benchmark decides ahead of time that the past matters. On real conversations it seldom does, and the difficult part becomes recognizing the rare message where it does, which nothing tested here managed to do.
Paper Quest · 7 chapters · about 40 min
Play this paper
Learn it by doing: make the calls the authors made, guess the result before you see it, and defend it in a viva graded on your own words. Chapter 1 is right here.
Chapter 1 🧩 · The problem
Understanding a person takes months of talk. Testing that takes a real record, and real records are private.
You want to test whether an AI companion that chats with someone for months truly understands them: remembers what they said, infers who they are, and knows when the past matters.
The road ahead
- 1 · The problem ~7 min Testing whether an AI companion understands a person needs that person's real record, but real records are private, so tests get made up.
- 2 · What came before ~3 min
- 3 · The key idea ~8 min Use real months-long companion chats as the test, and make every label checkable by citing messages and carrying a verified reasoning trace.
- 4 · Choose your own research ~3 min
- 5 · Build the method ~8 min Record real relationships, derive four files from them, cite the evidence for each entry, then check every reasoning trace against the conversation.
- 6 · The experiment ~6 min You’ll guess: On real companion chats, for probes that genuinely need memory, how often does a simple window of recent messages contain the required message?
- 7 · The viva ~5 min Three questions from the examiners, answered in your own words. Win it for the paper’s trophy.
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