Міндетті талдау: мазмұны, әдістері және қолданылуы

Analysis of how a task is accomplished
Task analysis is a fundamental tool of human factors engineering. It entails analyzing how a task is accomplished, including a detailed description of both manual and mental activities, task and element durations, task frequency, task allocation, task complexity, environmental conditions, necessary clothing and equipment, and any other unique factors involved in or required for one or more people to perform a given task. Information from a task analysis can then be used for many purposes, such as personnel selection and training, tool or equipment design, procedure design (e. g., design of checklists, or decision support systems) and automation. Though distinct, task analysis is related to user analysis.

If task analysis is likened to a set of instructions on how to navigate from Point A to Point B, then Work domain analysis (WDA) is like having a map of the terrain that includes Point A and Point B. WDA is broader and focuses on the environmental constraints and opportunities for behavior, as in Gibsonian ecological psychology and ecological interface design (Vicente, 1999; Bennett & Flach, 2011, p. 61)

Since the 1980s, a major change in technical documentation has been to emphasize the tasks performed with a system rather than documenting the system itself. In software documentation particularly, long printed technical manuals that exhaustively describe every function of the software are being replaced by online help organized into tasks. This is part of the new emphasis on usability and user centered design rather than system/software/product design. This task orientation in technical documentation began with publishing guidelines issued by IBM in the late 1980s. Later IBM studies led to John Carroll's theory of minimalism in the 1990s. With the development of XML as a markup language suitable for both print and online documentation (replacing SGML with its focus on print), IBM developed the Darwin Information Typing Architecture XML standard in 2000. Now an OASIS standard, DITA has a strong emphasis on task analysis. Its three basic information types are Task, Concept, and Reference. Tasks are analyzed into steps, with a main goal of identifying steps that are reusable in multiple tasks.

Hierarchical task analysis (HTA) is a task description method and a variant of task analysis. Task description is a necessary precursor for other analysis techniques, including critical path analysis (CPA). HTA is used to produce an exhaustive description of tasks in a hierarchical structure of goals, sub goals, operations and plans. In HTA, tasks are broken down into progressively smaller units.

Operations are the actions performed by people interacting with a system or by the system itself, and plans explain the conditions necessary for these operations. Operations describe the smallest individual task steps in the HTA, i. e. those which cannot be broken down into plans and further operations. They are the individual actions, such as 'visually locate control' or 'move hand to control', which the user must perform in a particular combination to achieve the goal of task completion.

Each level in the HTA should be numbered according to its hierarchical level: The overall goal is the highest hierarchical level and should be numbered 0. The first sub goal in the hierarchy will be 1, also with plan 1. Further levels just extend this system third hierarchical level: 1.1, fourth hierarchical level: 1.1.1, and so on. A HTA can be represented in list or diagram form. In list form lines should be indented to denote the different hierarchical levels. In diagram form each operation should be placed within a box and links should be made between them: a lower hierarchical level should branch from underneath a higher level operation. Plans should be written next to the branches to describe the way in which the branched operations should be carried out. Hence, the plans should be goal oriented to achieve the success of any field.

HTA is a task description method which is most commonly used as a starting point for further analyses such as multimodal CPA and SHERPA. On its own, HTA does not provide results for usability evaluation; however, you should be able to study the HTA in order to learn about the structure of different tasks. It may also allow you to highlight unnecessary task steps or potential errors that might occur in task performance. HTA is a fairly time consuming method to carry out as each individual operation in a task needs to be analysed; however, creating a comprehensive HTA can considerably reduce the time required for other modelling methods.