Abstract
Analytical measurement, the process by which the chemical composition of a substance is determined, is carried out in chemical laboratories throughout the world. It has been recognized for some time that results obtained from different laboratories are not as consistent as would be expected, but until recently little attention has been paid to the human factors and human error aspects of the task. However, analytical measurement is a multistage task that places high manual and cognitive demands on the operator, which are likely to be the source of considerable human error, as it is likely that the reliability of the task could be improved by the application of appropriate cognitive ergonomics. Task demands range from accuracy in manual, skill-based activities to complex, knowledge-based activities. This paper presents a hierarchical task analysis as a methodological framework for looking at the process of analytical measurement, followed by an account of the potential errors that can occur. These errors are then placed within a broader cognitive and human error framework. A series of recommendations as to how to reduce error at each of the stages of analytical measurement is described.