Open research

NerdSip Research

We study how people actually learn inside the NerdSip app. Every study is registered before we look at the data. Every result is published, including the ones that did not turn out the way we expected.

Updated

Line chart: share of quiz questions missed on the first attempt, by lesson position within the course, one line per course length. All lines are flat.

Figure 1 from Study 1. The share of questions missed on the first try, by the lesson's position in its course. Every line is flat: the last lesson is missed about as often as the first.

In one paragraph

Study 1 looked at 39,867 quiz answers from 2,590 learners. People missed the last question of a course about as often as the first one, so putting the important material first does not help. Learners also got about 1.5% faster with each lesson without making more mistakes. The study was preregistered on the Open Science Framework and is published as a preprint at edarxiv.org/9e5jy.

Study 1: Does attention fade during a short course?

Course designers are often told to put the most important material first, because attention supposedly drops as a course goes on. It is a sensible-sounding rule. We could not find anyone who had tested it on a real learning app, so we did.

A NerdSip course is 3 to 10 short lessons on one topic, taken in order, often spread over several days. Each lesson is about 130 words, shown a screen at a time, and ends with one easy three-option question. You have to answer it correctly to move on. We asked a simple question: is the question at the end of a course missed more often than the question at the start?

We wrote down our hypotheses and our analysis plan and registered them publicly on the Open Science Framework. Thirty-three minutes later we pulled the data: 39,867 first answers from 2,590 learners, across 994 courses and 5,169 questions, frozen on 20 July 2026.

What we found

QuestionAnswerHow sure
Are later lessons missed more often?No. The last lesson of a course is missed about as often as the first. Odds ratio 0.978 per position, and the interval rules out any effect big enough to justify front-loading.Preregistered. Held in every check we ran.
Do people slow down or speed up?They speed up, by about 1.5% per lesson, and they do not make more mistakes while doing it.Preregistered. Some of the speed-up is people tapping through, and we say so.
Do errors rise inside one long sitting?A little, but only in very long sittings, only for a few dozen learners, and smaller than the smallest effect we had registered as meaningful.Preregistered. Detectable, below our own bar.

What we thought we found, and did not

For a while it looked as if longer courses had more errors. The gap was there from the very first lesson, though, so nothing was building up. And it turned out to track who had generated the course, not how long it was. We report that openly in the paper. It is not a finding.

What this does not tell you

It is one app, with deliberately easy questions, and it describes learners who keep going. People who quit after a wrong answer are not in the later lessons. We did not measure attention itself, only whether a question was missed. Everything is an association, not a cause. The paper spells all of this out.

Read the paper

How to cite

Sergelius, P., & Hänze, M. (2026). Quiz errors do not rise with lesson position in mobile micro-learning: a preregistered analysis of 39,867 outcomes. EdArXiv preprint. https://edarxiv.org/9e5jy

The preprint has been submitted to a peer-reviewed journal. This page will link the published version when it exists.

Study 2: What people pick from the feed

The second study looks at 253,000 swipe decisions in the NerdSip feed and asks whether taste in topics differs by country, or mostly by person. It uses a split sample: we explored one half, wrote down what we expected to see, registered it at osf.io/7xp9q, and only then opened the other half. The write-up is in progress.

How we do research

For journalists

Three sentences you can use, all backed by the paper:

Questions, interviews, or the underlying tables in another form: [email protected]. Dr. Philip Sergelius and Dr. Max Hänze are the authors and the founders of NerdSip, Reinbek near Hamburg, Germany.

Related reading on NerdSip

Questions people ask

Is the study peer reviewed?

Not yet. It is a preprint, which means it is public and citable but has not been through journal review. It has been submitted to a journal. This page will link the reviewed version when it is out.

Can I quote or reuse the findings?

Yes. The preprint is published under a CC-BY 4.0 licence, so you can copy, quote and share it as long as you name the authors.

Did you publish user data?

No. Learners were replaced by random codes on the server before anything was extracted, and only aggregate numbers are published. Every published figure rests on at least 10 different learners. The row-level data and the key to the codes are not shared.

Why publish a result that says nothing happened?

Because the belief we tested shapes how courses are built, and a careful, registered test that finds no effect is exactly the evidence needed to stop following a rule that has no support.

Did AI write the paper?

AI helped. Analysis code, figures and drafts were produced with Claude by Anthropic. The authors reviewed and approved every analytic decision and take full responsibility, and the paper says so.