Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 27, 2017
Last Modified: January 02, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the dynamic (computerized) Bomb Risk Elicitation Task, a measure for risk propensity and risk aversion, as described in Crosetto & Filippin (2013).
Crosetto, P., & Filippin, A. (2013). The bomb risk elicitation task. J. Risk Uncertain. 47 (1), 31–65.
2 - 3 minutes
Participants see a grid of 100 (25) parcels and are told that one of these parcels hides a time bomb. The parcels are automatically removed, one-by-one (starting with the upper left parcel) until the participant stops the collection process. The participant earns a predetermined amount of money for each parcel removed. However, they can only keep the money if the time bomb is revealed to be located in one of the uncollected parcels.
Several parameter settings are possible (see section Editable Parameters): 1) the time bomb location can be determined by computer (default) or it can be manually determined by experimenter/participant ( key "I" advances to a trial that accepts manual input of a number) 2) the time bomb can go off immediately once the location has been collected or the location is determined after the participant stops the collection process (default) 3) participants can start with a "start capital" or without (start capital is immediately 'lost' when participants decide to play the game -> lost aversion setting) 4) number of parcels: choose btw. 25 or 100 parcels (default) 5) amount of money won per parcel: $0.1 (default) 6) collectionRate: the rate at which the parcels get collected (default: 1000ms per parcel) 7) number of rounds played: 1 (default; the BRET was originally designed to be a 1-choice task)
1. Demo: 1 round with no bomb location reveal
2. Testround(s) - by default only 1 round is run
initial presentation of the matrix (press Start)
-> a parcel is removed from the screen at 1parcel/second until Stop is pressed
(optional: if explosionmode is 'immediate', bombs goes off once the target parcel is collected)
-> bomb reveal
a 10x10 (5x5) matrix of blue parcels,
the setup is based on the ones by Crosetto & Filippin (2013)
provided by Millisecond.
The instructions are based on the ones provided by Crosetto & Filippin (2013) and are
presented in this script in the form of html pages. The html files can be edited directly
with simple text editors such as Notepad (windows) or TextEdit (Mac).
File Name: bombriskelicitationtask_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| bombLocationDrawingMode | Computer: the bomb location is randomly determined by the computer (-> list.parcels) (script default) manual: the bomb location is manually determined by experimenter |
| explosionMode | Delayed: the bomb location reveal is delayed until after the collection process is stopped (default) immediate: the bomb location is revealed immediately when the bomb has been collected for (manually) predetermined sequences used for 'immediate' explosions: go to section Editable Lists list.manualBombLocations |
| nrRounds | The number of rounds played (default: 1) the BRET was originally designed to be a 1-choice task |
| collectionRate | The rate at which the parcels get collected (default: 1000ms per parcel) |
| winAmount | The potential win amount per collected parcel (default: 0.1) |
| startCapital | Stores the amount of money provided as start capital (-> 'loss aversion' treatment). The start capital is lost immediately if participants decide to play the game. (default: 0 -> participant starts at 0) |
| nrParcels | The number of parcels in the grid (100 vs. 25) |
Dv |
|
| riskBehavior | If the number of collected parcels (in the case of multiple rounds: mean number of collected parcels) is less than parcelcount/2, the participant is classified as 'risk averse' if it is 'parcelcount/2', the participant is classified as 'risk neutral' if it is more than 'parcelcount/2', the participant is classified as 'risk seeker'. (Crosetto & Filippin, 2013, p.9) |
| total | Stores the total amount of money won from all rounds |
| meanExplosions | Proportion of explosions across rounds |
| meanParcelsCollected | The mean number of parcels collected across rounds |
| bombLocations | Stores the bomb locations of all rounds (in sequence) |
File Name: bombriskelicitationtask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| bombLocationDrawingMode | Computer: the bomb location is randomly determined by the computer (-> list.parcels) (script default) manual: the bomb location is manually determined by experimenter |
| explosionMode | Delayed: the bomb location reveal is delayed until after the collection process is stopped (default) immediate: the bomb location is revealed immediately when the bomb has been collected for (manually) predetermined sequences used for 'immediate' explosions: go to section Editable Lists list.manualBombLocations |
| nrRounds | The number of rounds played (default: 1) the BRET was originally designed to be a 1-choice task |
| collectionRate | The rate at which the parcels get collected (default: 1000ms per parcel) |
| winAmount | The potential win amount per collected parcel (default: 0.1) |
| startCapital | Stores the amount of money provided as start capital (-> 'loss aversion' treatment). The start capital is lost immediately if participants decide to play the game. (default: 0 -> participant starts at 0) |
| nrParcels | The number of parcels in the grid (100 vs. 25) |
| bomb | Stores the location (1-100 or 1-25) of the bomb |
| parcelsCollected | Counts the number of parcels selected |
| roundTotal | Stores the amount of money 'won' for the current round |
| total | Stores the total amount of money won from all rounds |
| explosion | 1 = yes => time bomb goes off (parcel collected) 2 = No => time bomb does NOT go off |
| response | The participant's response |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| latency | The response latency (in ms); measured from: onset of trial |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| bombLocationDrawingMode | Computer: the bomb location is randomly determined by the computer (-> list.parcels) manual: the bomb location is manually determined by experimenter key "I" advances to a trial that accepts manual input of a number once experimenter is alerted by participant | "computer" |
| explosionMode | Delayed: the bomb location reveal is delayed until after the collection process is stopped (default) immediate: the bomb location is revealed immediately when the bomb has been collected for (manually) predetermined sequences used for 'immediate' explosions: go to section Editable Lists list.manualBombLocations | "delayed" |
| startCapital | Stores the amount of money provided as start capital (-> 'loss aversion' treatment). The start capital is lost immediately if participants decide to play the game. | 0 |
| winAmount | The potential win amount per collected parcel | 0.1 |
| collectionRate | The rate at which the parcels get collected | 1000 |
| nrRounds | The number of rounds played the BRET was originally designed to be a 1-choice task | 1 |
| nrParcels | The number of parcels in the grid (choose from: 100 vs. 25) | 25 |