Effects of Alcohol Ingestion and Workload on Quality and Productivity for a Paced and Unpaced Assembly Task

Abstract

Eight subjects participated in an assembly task in which they assembled a simulated circuit board. The task required exact placement of three similarly coded resistors, which were chosen from a set of five resistors (two of which were included as distractors), followed by adjusting a voltmeter to a specified value. Participants performed the assembly task under various blood alcohol concentrations (Placebo, 0.05%, 0.07%, and 0.0 9%) to assess the effects of alcohol and workload on quality (i.e. accuracy) and productivity (i.e. speed). Three levels of paced task conditions (maximum speed for paced work, 75% and 50% of that maximum speed) and two levels of unpaced task conditions (speed and accuracy) were used for the assembly task conditions. In this study, six measures of performance were assessed: number of correctly completed units, number of orientation errors (i.e. one of the two pins of the resistor was misplaced and the other was in the correct hole), number of position errors (i.e. both pins missed the correct holes), meter adjustment errors, number improperly selected resistors, and number of incomplete boards (inaccurate boards). A significant alcohol effect ( p < 0.0001) was evident for all the dependent variables in the two pacing paradigms. Effects on the number of completed units and the number of inaccurate boards were significant ( p < 0.0001) for the paced task main effect. Under the unpaced condition, significance effects were obtained for the number of completed units ( p < 0.0001), the number of position errors ( p < 0.0001), the number of orientation errors ( p < 0.002), the number of adjustment errors ( p < 0.0001), the number of resistor errors ( p < 0.0001), and the number of inaccurate units ( p < 0.0001) for the task condition. Interactions of alcohol by paced task condition were significant for the number of inaccurate units ( p < 0.00161) and the number of completed units ( p < 0.0001). Unpaced condition revealed interaction effects for the number of completed units ( p < 0.0001), the number of position errors ( p < 0.0001), the number of resistor errors. The plots of these interactions did not reveal any obvious patterns. A generalized alcohol dosage formula was developed using existing data from previous research.