Task analysis refers to the broad practice of learning about how users work (i.e., the tasks they perform) to achieve their goals. Task analysis emerged out of instructional design (the design of training) and human factors and ergonomics (understanding how people use systems in order to improve safety, comfort, and productivity). Task analysis is crucial for user experience, because a design that solves the wrong problem (i.e., doesn’t support users’ tasks) will fail, no matter how good its UI.

In the realm of task analysis,任务是指通常可观察到的任何活动,并且具有开始和终点。例如,如果目标是设置退休基金,那么用户可能必须搜索良好的交易,与财务顾问交谈,并填写申请表 - 所有这些都是任务。重要的是不要将目标与任务混淆。例如,用户的目标不是填写形式。相反,用户可能会填写表单注册他们想要使用的服务(这将是目标)。

Task analysis is slightly different from job analysis (what an employee does in her role across a certain period of time — such as a week, month, or year) or workflow analysis (how work gets done across multiple people). In task analysis, the focus is on one user, her goal, and how she carries out tasks in order to achieve it. Thus, even though the name “task analysis” may suggest that the analysis is of just one task, task analysis may address multiple tasks, all in service of the same goal.

Task analysis focuses on how a user accomplishes her goal by completing tasks. It is different from workflow analysis — where several users are studied in order to understand the tasks they perform to achieve a shared organizational goal — and from job analysis, where one employee is studied over a period of time to understand the requirements for his role.

Studying users, their goals, and their tasks, is an important part of the design process. When designers perform task analysis, they are well equipped to create products and services that work how users expect and that help users achieve their goals easily and efficiently. Task analysis, as a method, provides a systematic way to approach this learning process. It can be flexibly applied to both existing designs (e.g., the use of an enterprise system) and system-agnostic processes (e.g., shopping for groceries).

The task-analysis process can be viewed as two discrete stages:

Stage 1: Gather informationon goals and tasksby observing and speaking with users and/or subject-matter experts.

Stage 2: Analyze the tasks performed to achieve goals了解任务和子任务的总数,它们的序列,层次结构及其复杂性。分析师通常会产生用于记录此分析的图表。

Stage 1: Gather Information

In stage 1, typically, a combination of methods is used to learn about user goals and tasks. They include:

  • Contextual inquiry:任务分析师访问用户现场并进行semistructured interviewto understand the user’s role, typical activities, and the various tools and processes used and followed. Then the analyst watches the user work. After a period of observation, the user is asked questions about what the analyst observed.
  • Interviewsusing the临界事件技术:要求用户回忆起关键事件,面试官询问了许多后续问题,以收集有关发生的事情的具体细节。故事提供关于所执行的任务,用户的目标以及问题所在的任务的详细信息。
  • Record keeping: Users are asked to keep records or日记参赛作品他们执行的任务over a certain period of time. Additionally, tracking software can be used for monitoring user activity.
  • Activity sampling: Users are watched or recorded for a certain period of time in order to document which tasks are being performed, as well as their duration and frequency.
  • Simulations:任务分析师遍历用户可能使用给定系统使用的步骤。

When carrying out research, do not rely solely on self-reported behavior (i.e., through interviews or surveys) or simulations (remember:你不是用户!), but alsoobserve the user at work in her own context。Otherwise, you could miss out on important nuances or details.

第2阶段:分析任务

在第2阶段,任务分析师将通过秩序,层次结构,频率甚至认知需求的某些属性构建观察,以分析过程用户的复杂性以实现目标。该分析的结果通常是称为a的图形表示任务分析图

可以产生许多不同类型的图表,例如标准流程图或操作序列图。但是,最常见的任务分析中的最常见和使用的是分层任务分析图(HTA)。下图显示了使用新的家庭扫描仪创建物理信的数字副本的目标的HTA的示例。

分层任务分析师从用户的目标开始:使用新的家庭扫描仪制作物理信的数字副本。这个目标被分解为4个任务。任务1:下载软件;任务2:启动扫描仪程序;任务3:扫描文件;任务4:保存文档。这些任务中的每一个都可以分解为进一步的子组织。例如,任务1将显示为6进一步的子任务:SubTask 1.1:检查打印机型号;SubTask 1.2:在线搜索打印机软件;subtask 1.3:单击链接以下载软件; subtask 1.4: enter app-store password; subtask 1.5: click reset password, and subtask 1.6: enter a new app-store password. Subtasks 1.5 and 1.6 are marked as only being performed if a user has forgotten their password.
尝试使用新的家庭扫描仪创建物理信函的数字副本的用户的分层任务分析(HTA)图涉及多个任务(或操作):将扫描仪软件下载到MacBook计算机上,启动程序,扫描文档,然后保存。

An HTA diagram starts with a goal and scenario (in the same way that a客户旅程地图does) and highlights the major tasks to be completed in order to achieve it. In human factors, these tasks are referred to as ‘operations’. Each of the tasks in the top layer can be broken down into subtasks. The number of levels of subtasks depends on the complexity of the process and how granular the analyst wants the analysis to be.

并非所有用户都以同样的方式完成目标。例如,新手用户可能比专家用户执行更多任务 - 后者可能会跳过某些步骤。HTA使这些差异能够通过“计划”来捕获。计划在每个级别指定步骤的顺序是什么,以及哪些步骤可以何时或向谁进行。例如,无法记住他的密码的用户必须进行步骤1.5(点击Reset password) and 1.6 (Enter a new app-store password) in order to accomplish the goal of downloading software for the scanner.

While a task-analysis diagram is useful to illustrate the overall steps in a process and is an excellent communication tool — especially forcomplex systems- 它也可以用作进一步分析的起点。例如,可以考虑HTA中的任务可以考虑以下属性。

  • The总体数字of tasks: Are there too many? Perhaps there are opportunities to create a design that could streamline the process and remove some steps.
  • Thefrequencyof tasks: How often are certain tasks performed? Are some tasks filled with repetition?
  • Thecognitive complexity任务:需要哪些心理过程(即,想法,判断和决定)来完成给定任务?(已知任务分析的整个分支认知任务分析关注这些问题,并使心理模式和流程可见)。如果涉及许多心理操作,整体任务的难度增加,分析师应考虑用户错误的可能性。
  • Thephysical requirementsof the task: What does the user need to physically do? Could this physical requirement affect user performance and comfort? And how could these physical requirements affect users with disabilities?
  • Thetime takento perform each task: Activity sampling or theoretical modeling (such as GOMS) can be used to estimate how long tasks would take users to complete.

At the end of the task analysis, the analyst has a good understanding of all the different tasks users may perform to achieve their goals and the nature of those tasks. Armed with this knowledge, the analyst can design (or redesign) an efficient, intuitive, and easy-to-use product or service.

Summary

Task analysis is a systematic method of studying the tasks users perform in order to reach their goals. The method begins with research to collect tasks and goals, followed by a systematic review of the tasks observed. A task-analysis diagram or an HTA is often the product of task analysis; the HTA can be used to communicate to others the process users follow, as well as a starting point for further assessment.

References

Hackos,J.A.T.,Redish,J.(1998)。User and task analysis for interface design。New York: Wiley.

Kirwan,B.(Ed。),Ainsworth,L.(ed。)。(1992)。任务分析的指导。London: CRC Press,https://doi.org/10.1201/b16826

Stanton, N. A. (January 01, 2006). Hierarchical task analysis: Developments, applications, and extensions.Applied Ergonomics, 37,1, 55-79.https://doi.org/10.1016/j.apergo.2005.06.003