Date of Award


Degree Name

Doctor of Philosophy




Recent research endeavors have demonstrated the existence of an observer effect . In other words, conducting safety observations increases the safetyperformance of the observer, and may result in safety-related verbalizations. The purpose of this study was to help determine whether observers make self-verbalizations regarding their safety performance and whether these reports are functionally related to safety performance. In order to answer these questions two experiments were conducted using both protocol analysis and the silent dog method. Protocol analysis is used by cognitive scientists to analyze thethoughts of a person as they perform a task, and the silent dog method allows researchers to determine the behavioral function of the thoughts or verbalizations that occur during task completion.

The objective of Experiment 1 was two-fold: (a) to show that safety performance with continuous, concurrent talk-aloud procedures is functionally equivalentto safety performance without talk-aloud reports, and (b) to demonstrate that safety performance is altered when participants were presented with a distracter task. A multiple baseline counterbalanced across three postural safety behaviors was conducted in a laboratory setting. Participants were randomly assignedto one of two groups: talk-aloud or silent group. Both groups performed an assembly task and were exposed to an information, observation and distracter phase. Participants conducted safety observations on a confederate's performance during the observation phase. The safety-related verbalizations made during this phase were recorded, analyzed, and used to establish descriptions of safety rules. These descriptions were presented to Experiment 2 participants in place of the observation phase. The goal of Experiment 2 was to demonstrate that the safety-related verbalizations made by Experiment 1 participants were task-relevant and functionally related to safety performance.

The results from both Experiments 1 and 2 provide strong support for the existence of a functional relationship between safety-related verbalizations and increases in safety performance. These results also seem to suggest that conducting safety observations may serve a (a) rule generating function, and/or (b) self-monitoring function. This is a first step toward helping determine the behavioral function of conducting safety observations and understanding the observation process employed by behavioral safety processes.

Access Setting

Dissertation-Open Access