Measuring base-rate bias error in workplace safety investigators

Area of Science:

• Cognitive Psychology
• Industrial Safety
• Organizational Behavior

Background:

• Professional investigators may exhibit bias, attributing workplace incidents to human error rather than situational factors.
• This human error bias can reduce corporate accountability and the effectiveness of preventative measures.

Purpose of the Study:

• To quantify the magnitude of human error bias in professional industrial investigators.
• To compare the bias in professionals versus a lay control group.
• To explore the implications of this bias for industrial accident investigations.

Main Methods:

• Participants (professional investigators and undergraduates) were presented with a balanced workplace event summary.
• They allocated causal factors between a worker and a tire.
• Effect size analysis was used, incorporating previous research.

Main Results:

• Both professional investigators and the lay control group exhibited human error bias.
• The bias was significantly larger in professional investigators (d=0.97) compared to the control group (d=0.32).
• Professionals remained confident in their objectivity despite their bias.

Conclusions:

• The human error bias is quantifiable and demonstrably stronger in professional investigators.
• Understanding and mitigating this bias is crucial for accurate investigations and effective safety interventions.