Write 4 pages with APA style on The Mental Workload Definition and Assessment. First it was manual gear vehicles and today it is automatic gear vehicles. Therefore drivers workload is affected, accidents do not occur because drivers never received well training but probably their mental workload is affected, for instance there are many vehicles on the road and the driver must be extra careful, some cars have radio, car phone and route guidance system. All these need drivers’ attention, the external technological demand and the normal task they have to achieve. Mental workload can be defined therefore as a relative concept, the ratio of demand to allocated resources. It is the measure of the amount and types of work performed by an individual within a period of time (Hancock, et al, 1990). Ways of assessing mental workload. As stated above mental workload is an attribute of person task and the effects of such workload on human performance (Gopher, 1986).There are several ways of measuring mental workload because if the worker is overworked for instance, his mental and physical workload can be significantly interfered with and this can affect the worker adversely. There are ways to help asses the mental workload of an operator. We have subjective measures that include the actual estimation of the workload and performance measures that help to determine the reaction time, number correct and number detected (Hancock, et al, 1990). We also have analytical measures and psychological measure that include measuring heart rate, heart rate variability and brain activity. These techniques if well used shall enable us to determine the mental workload of an individual and the limit at which the workload should reach so that any adverse effected relating to extreme workload such as accidents on the road for a driver or the plane crash for a pilot (Andre, et al, 1995). In this context, I am going to discuss subjective measures into details. Subjective measures are based on operator rating of the task, they involve judgments of the effort and also reflect the direct opinion of the operator in context of the task environment and skills and experience level of the operator. Since subjective mental workload methods provide a complete self-assessed estimate of workload, subjective metrics simply gives relative rather than absolute data. There are three best tested ways to assess mental workload, unidimensional measures of mental workload. Here we use Bedford scale to show an operator spare mental capacity while completing the task. A hierarchical decision tree is used where the operator completes a ten-point rating where each point is accompanied by a descriptor factor of the associated level of workload (Andre, et al, 1995). Another subjective measure which is frequently used is known as multidimensional. Here two rating scales are used, the Task Load Index (NASA) and the Subjective Workload Assessment Techniques (SWAT). Applications of mental workload assessment Mental workload assessment has brought practical use in the today’s world. Its analysis has enabled the determination of its pros and cons across the world. For instance subjective assessment techniques have found its use in flight industry where it is used in testing the flight operational and evaluation. Secondly, the concept of mental workload has greatly found its application in the manufacturing and administrative tasks .