Evaluation of Simulation vs. Classroom-Based Implicit Bias Training to Improve Police Decision Making and Enhance the Outcomes of Police-Citizen Encounters, California, 2019-2021 (ICPSR 39309)

Version Date: Jun 12, 2025

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Principal Investigator(s):
Lois James, Washington State University-Spokane

https://doi.org/10.3886/ICPSR39309.v1

Version V1

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Summary

This study evaluated the impact of implicit bias and counter bias training interventions for improving police behavior and public perceptions of bias. A random selection of Body Worn Camera (BWC) videos from a large and diverse municipal agency were scored before and after training using a validated tool for coding police behavior. The variables coded from BWC videos were compiled into Body Worn Camera Data (DS1) and include demographic details on citizens and officers, circumstances of the incident, and the behavior of both the officer and citizen. During pre- and post- intervention measurement periods, "discrimination"-based community member complaints were also collected. Information about these complaints including the type, incident date, and complaint findings was compiled into Complaints Data (DS2).

Citation

James, Lois. Evaluation of Simulation vs. Classroom-Based Implicit Bias Training to Improve Police Decision Making and Enhance the Outcomes of Police-Citizen Encounters, California, 2019-2021. Inter-university Consortium for Political and Social Research [distributor], 2025-06-12. https://doi.org/10.3886/ICPSR39309.v1

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Funding

United States Department of Justice. Office of Justice Programs. National Institute of Justice (2017-R2-CX-0024)

Subject Terms

Geographic Coverage

Restrictions

Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reason for the request, and obtain IRB approval or notice of exemption for their research.

Distributor(s)

Inter-university Consortium for Political and Social Research
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Time Period(s)

2019 -- 2021

Date of Collection

2019-01 -- 2019-12 (Baseline Data Collection Period), 2020-01 -- 2020-12 (Intervention Period), 2021-01 -- 2021-10 (Post-Intervention Data Collection Period)

Data Collection Notes

  1. This data collection includes a data analysis file documenting system analyses conducted by the research team. Users should refer to this documentation for details on the mixed effects models used to analyze differences in officer performance between treatment groups and before and after training.

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Study Purpose

The purpose of this study was to evaluate the outcomes of classroom-based implicit bias training and simulation-based counter bias training. This research addressed the following research questions:

  1. Can implicit bias training impact police behavior by improving fairness in decision-making during interactions with community members?
  2. Can implicit bias training impact community member perceptions of police bias based on discrimination complaints?
  3. Is classroom-based training, simulation-based training, or a combination of both most effective at improving fairness in police decision making and reducing perceptions of bias in community members?
  4. What are officer perceptions of implicit bias training?

Study Design

Researchers partnered with a large municipal law enforcement agency to gain access to a sample of patrol officers (n=400) and administrative data to conduct this on-site field experiment. Body worn camera footage (BWC) and discrimination-based community member complaints were collected over a 12-month period (the 2019 calendar year) to establish a baseline measurement of officer behavior before separating officers into treatment groups, randomized at the patrol district level. Approximately 50 officers received classroom-based implicit bias training, 100 received simulation-based counter bias training, 50 received both trainings, and a control group of approximately 200 received neither. The pre-determined interventions took place during the 2020 calendar year, and post-intervention data collection (coding BWC footage and documenting complaints) took place January through October 2021.

Sample

During the 2019 baseline and 2021 post-intervention data collection periods, over 750,000 body worn camera videos were collected from officers. Researchers compiled and coded a random sample of approximately 1000 videos from the baseline period and approximately 600 from the post-intervention period to form the Body Worn Camera Data (DS1). These samples included three videos per calendar day within the sampling period, representing the day (06:00-16:00), evening (14:30-00:30), and night (21:00-07:00) shifts worked by officers.

All discrimination-based community complaints filed against officers within the two data-collection periods were compiled to form the Complaints Data (DS2).

Universe

Police officers from a large municipal agency.

Unit(s) of Observation

Individual, Event

Data Type(s)

Mode of Data Collection

Description of Variables

The Body Worn Camera Data (DS1) include details about police encounters with citizens, coded by researchers and based on body worn camera footage. These data describe the citizen's demographics (race, gender, socio-economic status, etc.), mental state (i.e. under the influence, suffering a mental health crisis), behavior (i.e. hostile, disrespectful), whether they were armed or not, and their attire. Other variables include coded interpretations of an officer's behavior during the interaction (i.e. shows natural human emotion, communicates tasks) and outcome variables detailing whether the citizen was put in handcuffs, arrested, given a citation, subject to the use of force (taser, K9, pepper spray, etc.).

The Complaints Data (DS2) describe complaints filed against officers involved in this study, including the complaint type, date that the incident occurred, and date that the complaint was received.

Both datasets are organized at the officer-level and include the variable GROUP, which indicates what treatment group the officer belonged to.

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Original Release Date

2025-06-12

Version History

2025-06-12 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.

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Notes

  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

  • One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.