The Risk Preferences Task is a behavioral measure of risky decision-making that occurs in three series. In each series, participants must choose to draw a ball from one of two jars: Jar A or Jar B. Jar A and Jar B each contain two balls with an equal probability of being chosen at random (50%). The first round is an unpaid practice round, after which Series 1-3 occur. In Series 1 (choices over gains), the participant begins with 1000 KSH (KSH is a monetary unit; 100 KSH is ~ 1 USD), and makes 10 decisions about which jar to choose from. Jar A contains a blue ball worth 400 KSH and a red ball worth 300 KSH, and Jar B contains an orange ball worth 50 KSH and a green ball with a value that varies from 620 KSH to 1300 KSH. For Series 2, the participant receives an additional 1000 KSH endowment. Series 2 (choices over losses) also comprises 10 decisions, in which Jar A contains a blue ball (400 KSH loss) and a red ball (300 KSH loss), and Jar B contains an Orange ball (50 KSH loss) and a green ball (540 KSH loss to 830 KSH loss). For Series 3, the participant receives an additional 350 KSH endowment. In Series 3 (choices over gains and losses), Jar A contains a red ball (gain of 10 KSH, 40 KSH or 250 KSH) and a blue ball (loss of 40 KSH or 80 KSH), and Jar B contains a green ball (gain of 300 KSH) and an orange ball (loss of 110 KSH, 140 KSH, 160 KSH, or 210 KSH).
The task is scored following the methodology in Tanaka, Camerer & Nguyen (2010). It is assumed that participant decisions are utility-maximizing in a prospect theory framework. This model is characterized by parameters for risk aversion and loss aversion which differ across participants. An iterative process allows the researcher to derive the set of values for these parameters which would rationalize each participant’s choices. For more details, see section II.B of Tanaka, Camerer & Nguyen (2010)
The Science of Behavior Change (SOBC) program seeks to promote basic research on the initiation, personalization and maintenance of behavior change. By integrating work across disciplines, this effort will lead to an improved understanding of the underlying principles of behavior change. The SOBC program aims to implement a mechanisms-focused, experimental medicine approach to behavior change research and to develop the tools required to implement such an approach. The experimental medicine approach involves: identifying an intervention target, developing measures to permit verification of the target, engaging the target through experimentation or intervention, and testing the degree to which target engagement produces the desired behavior change.
Within the SOBC Measures Repository, researchers have access to measures of mechanistic targets that have been (or are in the processing of being) validated by SOBC Research Network Members and other experts in the field. The SOBC Validation Process includes three important stages of evaluation for each proposed measure: Identification, Measurement, and Influence.
The first stage of validation requires a measure to be Identified within the field; there must be theoretical support for the specific measure of the proposed mechanistic target or potential mechanism of behavior change. This evidence may include references for the proposed measure, or theoretical support for the construct that the proposed measure is intended to assess. The second stage of validation requires demonstration that the level and change in level of the chosen mechanistic target can be Measured with the proposed measure (assay). For example, if the proposed measure is a questionnaire, the score on the measure should indicate the activity of the target process, and it must have strong psychometric properties. The third stage of validation requires demonstration that the measure can be Influenced; there must be evidence that the measured target is malleable and responsive to manipulation. Evidence relating to each stage includes at least one peer-reviewed publication or original data presentation (if no peer-reviewed research is available to support the claim) and is evaluated by SOBC Research Network Members and experts in the field.
Once a measure has gone through these three stages, it will then either be Validated or Not validated according to SOBC Research Network standards. If a measure is Validated, then change in the measured target was reliably associated with Behavior Change. If a measure is Not validated, then change in the measured target was not reliably associated with Behavior Change. Why would we share measures that are not validated? The SOBC Research Network values open, rigorous, and transparent research. Our goal is to make meaningful progress and develop replicable and effective interventions in behavior change science. Therefore, the SOBC sees value in providing other researchers in the field with information regarding measures that work and measures that fall short for specific targets. Further, a measure that is not validated for one target in one population may be validated in another target or population.
Want to learn more? For any questions regarding the SOBC Validation Process or Measures Repository, please email info@scienceofbehaviorchange.org.
Has the mechanism been identified as a potential target for behavior change? This section summarizes theoretical support for the mechanism.
Have the psychometric properties of this measure been assessed? This section includes information such as content validity, internal consistency, and test-retest reliability.
Has a study manipulation led to change in the mechanism? This section addresses evidence that this measure is modifiable by experimental manipulation or clinical intervention.
Has a change in this mechanism been associated with behavior change? This section addresses empirical evidence that causing change in the measure reliably produces subsequent behavior change.