Type VIII Error
The Type VIII error refers to the phenomena where the correctly decided action has been incorrectly implemented. While it is coined in this text by the authors, it has its roots in the study of human error by psychologist and human factors researcher James Reason. In his seminal text on the subject, Reason (1990) discusses a number of different causes for accidents involving humans, and Type VIII errors exist under the general category known as unsafe acts. In order to understand the Type VIII error, it is useful to distinguish between errors and violations. Errors are defined as “mental or physical activities of individuals that fail to achieve their intended outcome” (Shappell and Wiegmann, 2000, p. 3), while a violation is a “willful disregard for the rules and regulations...” (Shappell and Wiegmann, 2000, p. 3). The Type VIII error specifically addresses this notion of error and not a violation. That is to say, unsafe acts that are committed on purpose, i.e., acts of sabotage, are not errors and are not addressed for the purposes of our discussion.
An example of the Type VIII error is one that many of us have no doubt experienced in our daily lives. A distracted driver is talking on his cell phone, adjusting the radio and generally, not devoting 100% of his attention to the task of driving. As a result, he misses his exit on the freeway. Having traveled the route numerous times before, there was no confusion regarding the way to his destination (i.e., the correct action), rather he incorrectly implemented it (i.e., he deviated from his plan). His actions represented a Type VIII error and not a willful violation. Within the medical world, we can consider an analogy in which a patient is responsible for taking a dose of medication at a prescribed time every day, say before bed. Failure to do so, in spite of knowledge of the directions, constitutes a Type VIII error. The patient knew that the medicine was to be taken each night before bed and simply committed an error. Perhaps he forgot, or some other circumstance prevented him from correctly implementing the correct action, i.e., taking his medicine according to the directions.
Once we have acted and hopefully avoided the Type IV, V, and VIII errors, we must now observe the effects of our actions. During observation, there are also opportunities for committing errors.