The wheel and the guess.
Does the number shown by a randomly spinning wheel affect your estimate on a question it has nothing to do with?
Original study
- Tversky, A., & Kahneman, D. (1974). Judgment under uncertainty: Heuristics and biases. Science, 185(4157), 1124–1131. Source
- Jacowitz, K. E., & Kahneman, D. (1995). Measures of anchoring in estimation tasks. Personality and Social Psychology Bulletin, 21(11), 1161–1166. Source
- Strack, F., & Mussweiler, T. (1997). Explaining the enigmatic anchoring effect: Mechanisms of selective accessibility. Journal of Personality and Social Psychology, 73(3), 437–446. Source
- Englich, B., Mussweiler, T., & Strack, F. (2006). Playing dice with criminal sentences: The influence of irrelevant anchors on experts' judicial decision making. Personality and Social Psychology Bulletin, 32(2), 188–200. Source
- Klein, R. A., Ratliff, K. A., Vianello, M., Adams, R. B., Jr., Bahník, Š., Bernstein, M. J., ... Nosek, B. A. (2014). Investigating variation in replicability: A “many labs” replication project. Social Psychology, 45(3), 142–152. Source
- Furnham, A., & Boo, H. C. (2011). A literature review of the anchoring effect. The Journal of Socio-Economics, 40(1), 35–42. Source
Our adaptation
A four-question adaptation of Tversky and Kahneman's (1974) wheel anchor and the anchoring index design of Jacowitz and Kahneman (1995). For each question the wheel stops at a low or a high anchor assigned at random to the participant; first the participant says whether the answer is more or less than that number (before or after, for the year question), then gives a numeric estimate. The true answers and sources are shown after all four questions.
Differences from the original study
- Although the wheel looks random, it stops on one of only two numbers per question; this is stated on the result screen.
- The effect is measured by comparing the two anchor groups, not at the individual level.
- There is no reward and answers can be looked up online.
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 |
|---|---|---|
anchor_1 | low | high | Anchor shown for the question (low | high); the number at the end of the column is the question order. (item 1) |
anchor_2 | low | high | Anchor shown for the question (low | high); the number at the end of the column is the question order. (item 2) |
anchor_3 | low | high | Anchor shown for the question (low | high); the number at the end of the column is the question order. (item 3) |
anchor_4 | low | high | Anchor shown for the question (low | high); the number at the end of the column is the question order. (item 4) |
dir_1 | more | less | Answer to the comparison question (more = more / after, less = less / before). (item 1) |
dir_2 | more | less | Answer to the comparison question (more = more / after, less = less / before). (item 2) |
dir_3 | more | less | Answer to the comparison question (more = more / after, less = less / before). (item 3) |
dir_4 | more | less | Answer to the comparison question (more = more / after, less = less / before). (item 4) |
est_1 | number | Numeric estimate (in the question's unit). (item 1) |
est_2 | number | Numeric estimate (in the question's unit). (item 2) |
est_3 | number | Numeric estimate (in the question's unit). (item 3) |
est_4 | number | Numeric estimate (in the question's unit). (item 4) |
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 an anchor, a comparison answer and an estimate within the question's allowed range for all four questions; incomplete submissions are 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
This experiment has no leaderboard score. The crowd result is the anchoring index: (median of the high-anchor group − median of the low-anchor group) / (high anchor − low anchor).
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.