Find the target.
Is there a red vertical bar on the screen or not: how fast can you decide?
Original study
- Treisman, A. M., & Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology, 12(1), 97–136. Source
- Wolfe, J. M., Cave, K. R., & Franzel, S. L. (1989). Guided search: An alternative to the feature integration model for visual search. Journal of Experimental Psychology: Human Perception and Performance, 15(3), 419–433. Source
- Wolfe, J. M. (1994). Guided Search 2.0: A revised model of visual search. Psychonomic Bulletin & Review, 1(2), 202–238. Source
- Wolfe, J. M. (1998). What can 1 million trials tell us about visual search? Psychological Science, 9(1), 33–39. Source
- Wolfe, J. M., & Horowitz, T. S. (2017). Five factors that guide attention in visual search. Nature Human Behaviour, 1(3), 0058. See also: Wolfe, J. M., & Horowitz, T. S. (2004). What attributes guide the deployment of visual attention and how do they do it? Nature Reviews Neuroscience, 5(6), 495–501. https://doi.org/10.1038/nrn1411 Source
- Wolfe, J. M., Horowitz, T. S., & Kenner, N. M. (2005). Rare items often missed in visual searches. Nature, 435(7041), 439–440. Source
- Evans, K. K., Birdwell, R. L., & Wolfe, J. M. (2013). If you don't find it often, you often don't find it: Why some cancers are missed in breast cancer screening. PLoS ONE, 8(5), e64366. Source
Our adaptation
An adaptation of Treisman and Gelade's (1980) visual search task. Each display shows 6, 12 or 24 bars placed at random on an invisible 6 × 5 grid; the target (a red vertical bar) is present on half the trials and the participant answers 'present' or 'absent' (F and J on a keyboard). In round 1 (feature search) all distractors are green verticals; in round 2 (conjunction search) half are green verticals and half red horizontals; round 3 mixes both types with a 2,500 ms limit. Each round has 12 trials.
Differences from the original study
- Trial counts are small; individual slopes are noisy and reliable slopes are computed from the crowd.
- Display timing varies by device; touch responses can be slower than mouse or keyboard.
- A color vision mode for people who find red-green hard is kept separate.
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 |
|---|---|---|
feat_rt | number | Round 1 (feature): median time of correct target-present trials (ms). |
feat_acc | number | Round 1: accuracy (all trials). |
feat_slope | number | Round 1: slope of time against set size on correct target-present trials (ms/item, least squares; empty with fewer than 3 trials). |
conj_rt | number | Round 2 (conjunction): median time of correct target-present trials (ms); empty if accuracy is below 80%. |
conj_acc | number | Round 2: accuracy. |
conj_slope | number | Round 2: slope (ms/item). |
mix_acc | number | Round 3 (mixed, time-limited): accuracy. |
trials | JSON | Trials: [{"b": round (0 feature, 1 conjunction, 2 mixed), "n": set size, "p": target present, "c": correct, "rt": time in ms}]. |
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 requires at least 12 valid trials and computes the summary measures from the trial records itself; trial times must be between 0 and 6,000 ms.
- 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: median time of correct target-present trials in round 2 (conjunction search, ms); lower is better. Not ranked if accuracy in that round is below 80%.
Leaderboard measure: hard search (lower is better). The play_score column in the open data is this score for the first play.
Version notes
- 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.