How fast are you?.
Tap as fast as you can: first the moment the screen turns orange, then on the box that lights up, and finally only when a green circle appears.
Original study
- Donders, F. C. (1969). On the speed of mental processes (W. G. Koster, Trans.). Acta Psychologica, 30, 412–431. (Original work published 1868.) Source
- Hick, W. E. (1952). On the rate of gain of information. Quarterly Journal of Experimental Psychology, 4(1), 11–26. Source
- Hyman, R. (1953). Stimulus information as a determinant of reaction time. Journal of Experimental Psychology, 45(3), 188–196. Source
- Der, G., & Deary, I. J. (2006). Age and sex differences in reaction time in adulthood: Results from the United Kingdom Health and Lifestyle Survey. Psychology and Aging, 21(1), 62–73. Source
- Woods, D. L., Wyma, J. M., Yund, E. W., Herron, T. J., & Reed, B. (2015). Factors influencing the latency of simple reaction time. Frontiers in Human Neuroscience, 9, 131. (Choice reaction time slope by age: Woods et al., 2015, Frontiers in Human Neuroscience, 9, 193.) Source
- Anwyl-Irvine, A., Dalmaijer, E. S., Hodges, N., & Evershed, J. K. (2021). Realistic precision and accuracy of online experiment platforms, web browsers, and devices. Behavior Research Methods, 53(4), 1407–1425. See also: Pronk, T., Wiers, R. W., Molenkamp, B., & Murre, J. (2020). Mental chronometry in the pocket? Timing accuracy of web applications on touchscreen and keyboard devices. Behavior Research Methods, 52(3), 1371–1382. https://doi.org/10.3758/s13428-019-01321-2 Source
- Logan, G. D., & Cowan, W. B. (1984). On the ability to inhibit thought and action: A theory of an act of control. Psychological Review, 91(3), 295–327. Source
- Wessel, J. R. (2018). Prepotent motor activity and inhibitory control demands in different variants of the go/no-go paradigm. Psychophysiology, 55(3), e12871. Source
Our adaptation
A three-part reaction time task based on Donders' (1868) three methods. In part 1 a dark screen turns orange after a random wait of 1.5–4 seconds (5 trials, simple reaction). In part 2 one of four boxes lights up and is tapped (8 trials, choice reaction). Part 3 is a 16-trial go/no-go task: tap the green circle, do not tap the red one; a quarter of the trials are red. Taps are timed with the pointerdown event.
Differences from the original study
- Screen, browser and touch surface add a device-dependent delay; values are usually tens of milliseconds longer than in the lab.
- Trial counts are small (5, 8 and 16); there are only 4 no-go trials.
- The order of the parts is fixed.
Measured variables
The columns of the open data file. List fields are expanded into numbered columns (for example rt_60, est_3); JSON columns contain only numbers and fixed stimulus names.
| Column | Type | Description |
|---|---|---|
simple | integer | Part 1: median simple reaction time (ms). |
choice | integer | Part 2: median four-choice reaction time (ms; trials with a wrong box excluded). |
false_starts | integer | Part 1: number of taps before the signal or faster than 100 ms. |
go | number | Part 3: median reaction time to the green circle (ms). |
fa | integer | Part 3: number of taps on the red circle. |
fa_pct | number | Part 3: percentage of red trials that were tapped. |
miss | integer | Part 3: number of missed green trials. |
cerr | integer | Part 2: number of taps on the wrong box. |
Columns present in every file (14)
row_id | string | Row code. Regenerated at random in every release; it does not identify a person and cannot be matched across releases or experiments. |
experiment | string | Short name of the experiment (URL slug). |
experiment_version | integer | Version of the answer format. For experiments whose format changed, only the current format is published. |
date | YYYY-MM-DD | YYYY-Www | YYYY-MM | Day the answer was given (Istanbul time). If fewer than 5 answers share the same day, language and device, it is coarsened to the ISO week, and to the month if that is still too few. |
date_precision | day | week | month | Precision of the date column. |
lang | tr | en | (boş) | Interface language. Language recording started in the first week of October 2026; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise. |
device | desktop | mobile | tablet | (boş) | Device class reported by the browser (class only; browser details are neither stored here nor published). |
source | site | embed | Where the answer came from: the balabs site or the experiment embedded on another site. The embedding site is not published. |
mode | free | daily | challenge | race | session | (boş) | Play mode in scored experiments: free play, daily round, challenge, race room, experiment session. Empty for unscored experiments and for older answers that did not store it. |
color_vision | normal | rg | by | contrast | (boş) | In color-based experiments, the color vision mode the participant chose: normal, red-green, blue-yellow or high contrast. Stimuli are generated along different axes per mode, so compare within a mode. Empty for other experiments. |
first_play | 1 | Every row is a participant’s first play of this experiment (always 1). Replays are stored only as leaderboard scores and are not part of the open data. |
seen_before | yes | no | unsure | (boş) | Participant’s own report of whether they had seen this experiment or its known answer before (in experiments that ask). |
duration_s | number | Time from the start of the experiment to submitting the answer, in seconds (measured in the browser, 0.1 s). |
play_score | number | Leaderboard score of the first play (scored experiments; defined on the method card). Empty for unscored experiments. |
Exclusion criteria
The browser counts taps under 100 ms as false starts and leaves them out of the median. The server accepts a simple median between 100 and 2,000 ms and a choice median between 100 and 3,000 ms; anything else is rejected.
- Only each participant's first answer to this experiment; replays are not included.
- Simulated rows, bots, banned and sample accounts are not included.
- Answers before 3 October 2026 are not included (the first day the open data notice was live).
Scoring
Leaderboard score: the part-1 simple reaction median (ms); lower is better. Medians below 120 ms are treated as humanly impossible and are not ranked.
Leaderboard measure: simple reaction (lower is better). The play_score column in the open data is this score for the first play.
Version notes
- October 2026
Plausibility bounds were tightened: anticipatory responses (below 200 ms for Stroop and rotation, below 100 ms for reaction time) are left out of the median on the client, and the server rejects shorter medians (the previous floor was 150 ms, 80 ms for reaction time).
- October 2026
This experiment started storing the play mode (free, daily, challenge, race, session) with the answer; the mode column is empty for earlier answers.
- October 2026
The interface language (lang) started being stored with each answer; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise.