"This taxonomy provides a structure for identifying human factors for the purpose of scientific research and system test and evaluation. The information contained in this document is provided as guidance, not mandated as direction. This taxonomy can be considered during the planning, conduct, and analysis of human factors. The objectives of this taxonomy are to: (1) identify an extensive list of human factors, (2) promote commonality in nomenclature and units of measurement, and (3) enable the development and use of a common human-factors taxonomy for data collection and data processing. The purpose of this Guide is to aid the reader in identifying human factors. The reader is assumed to have a basic knowledge of experimental design, statistics, and human performance. This Guide may also be used for task analysis. The purpose of analyzing performance of selected tasks, subtasks, and task elements contained in the task inventory by addressing the lowest taxonomic level specified by the procuring activity is to describe task performance in terms of human performance time and accuracy. The product of the analytic effort is intended for use in support of equipment design, testing and evaluation, training requirements identification, manning and workload assessment, development of training and maintenance manuals, and other documentation and reporting."