The Corruption of a Measurement System Due to Unintentional Bias: A Preliminary Macro-Ergonomic Study

Abstract

For the better part of the century, researchers have been analyzing the effect of an external prompt on human behavior. The phenomenon described by previous research has been dubbed the Pygmalion effect. This study looks at the effect an external prompt has on subsequent human behavior in a different setting than traditional Pygmalion studies. It examines the reaction of humans to external prompts in a measurement setting. The primary hypothesis of the research states that in a measurement system, indications about the expected outcome of inspections can lead people to inadvertently change their measurement techniques such that their results are significantly skewed toward the bias value compared to an unprompted group. The study was performed on 24 college students, measuring corruption in two different types of measurement systems, a rigid mechanical system and a visual inspection system. In two of the four measurement tasks in the rigid mechanical system, the evidence supported the hypothesis that a bias can be introduced. In the visual inspection system, each of the two measurement tasks supported the existence of an unintentional measurement bias. This study presents a challenge to the objectivity of measurement systems, which is a generally accepted, and poses several research questions from which future studies can be spawned and is a concern to researchers and practitioners interested in this aspect of macro-ergonomics.