Remember the spot.
How accurately can you point to where three dots appeared one after another inside a circle, one second later?
Original study
- Huttenlocher, J., Hedges, L. V., & Duncan, S. (1991). Categories and particulars: Prototype effects in estimating spatial location. Psychological Review, 98(3), 352–376. Source
- Huttenlocher, J., Hedges, L. V., Corrigan, B., & Crawford, L. E. (2004). Spatial categories and the estimation of location. Cognition, 93(2), 75–97. Source
- Wedell, D. H., Fitting, S., & Allen, G. L. (2007). Shape effects on memory for location. Psychonomic Bulletin & Review, 14(4), 681–686. Source
- Bays, P. M., & Husain, M. (2008). Dynamic shifts of limited working memory resources in human vision. Science, 321(5890), 851–854. Source
- Gorgoraptis, N., Catalao, R. F. G., Bays, P. M., & Husain, M. (2011). Dynamic updating of working memory resources for visual objects. Journal of Neuroscience, 31(23), 8502–8511. Source
- Smyth, M. M., & Scholey, K. A. (1996). Serial order in spatial immediate memory. The Quarterly Journal of Experimental Psychology Section A, 49(1), 159–177. Source
Our adaptation
An adaptation of the location memory task of Huttenlocher, Hedges and Duncan (1991). In each round three dots of different colors appear one after another inside a large circle (600 ms each, 250 ms apart); after a 1-second blank wait the dots are asked about in random order and their positions are tapped. There are no axes, grid or center mark inside the circle.
Differences from the original study
- Error is relative to the radius; screen size and viewing distance are unknown.
- Finger taps are less precise than mouse clicks.
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 |
|---|---|---|
d | JSON | Dots: [[round, presentation order, question order, target x, target y, answer x, answer y, time in ms] × 15] (circle center 0, radius 1). |
pts_1 | number | Round score: mean of three dots, dot score 10 / (1 + (d / 0.07)^1.6). (item 1) |
pts_2 | number | Round score: mean of three dots, dot score 10 / (1 + (d / 0.07)^1.6). (item 2) |
pts_3 | number | Round score: mean of three dots, dot score 10 / (1 + (d / 0.07)^1.6). (item 3) |
pts_4 | number | Round score: mean of three dots, dot score 10 / (1 + (d / 0.07)^1.6). (item 4) |
pts_5 | number | Round score: mean of three dots, dot score 10 / (1 + (d / 0.07)^1.6). (item 5) |
points | number | Total score (0–50). |
err | number | Mean location error (fraction of the radius). |
pull | number | Mean angular shift toward the diagonal of the target's quadrant (°; positive = toward the diagonal). |
toward | number | Percentage of answers shifted toward the diagonal. |
show_1 | number | Mean error by presentation order (1st, 2nd, 3rd dot). (item 1) |
show_2 | number | Mean error by presentation order (1st, 2nd, 3rd dot). (item 2) |
show_3 | number | Mean error by presentation order (1st, 2nd, 3rd dot). (item 3) |
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 server range-checks the values of all 15 dots and requires all five rounds. Targets very close to the center and angular deviations above 60° are left out of the shift measure.
- 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: total score (0–50); higher is better.
Leaderboard measure: location memory (higher is better). The play_score column in the open data is this score for the first play.
Version notes
- 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.