An illusion of objectivity in workplace investigation: The cause analysis chart and consistency, accuracy, and bias...

Investigation tools used in occupational health and safety events need to support evidence-based judgments, especially when employed within biasing contexts, yet these tools are rarely empirically vetted. A common workplace investigation tool, dubbed for this study the "Cause Analysis (CA) Chart," is a checklist on which investigators select substandard actions and conditions that apparently contributed to a workplace event. This research tests whether the CA Chart supports quality investigative judgments.

Professional and undergraduate participants engaged in a simulated industrial investigation exercise after receiving a file with information indicating that either a worker had an unsafe history, equipment had an unsafe history, or neither had a history of unsafe behavior (control). Participants then navigated an evidence database and used either the CA Chart or an open-ended form to make judgments about event cause.

The use of the CA Chart negatively affected participants' information seeking and judgments. Participants using the CA Chart were less accurate in identifying the causes of the incident and were biased to report that the worker was more causal for the event. Professionals who used the CA Chart explored fewer pieces of evidence than those in the open-ended condition. Moreover, neither the open-ended form nor the structured CA Chart mitigated the biasing effects of historical information about safety on participants' judgments.

Use of the CA Chart resulted in judgments about event cause that were less accurate and also biased towards worker responsibility. The CA Chart was not an effective debiasing tool. Practical application: Our results have implications for occupational health and safety given the popular nature of checklist tools like the CA Chart in workplace investigation. This study contributes to the literature stating that we need to be scientific in the development of investigative tools and methods.