【报告阅读】ISO 9241-210:2019

【ISO 9241-210:2019】Ergonomics of human-system interaction. Part 210: Human-centred design for interactive systems

写在前面

硕士阶段在芬兰的阿尔托大学修读人机交互专业(Human-Computer Interaction, HCI)。之前本科阶段对HCI方向知之甚少，中文博客中介绍该方向的文章也不多，遂决定记录一下求学的过程中接触的一些文章。

一定程度上作为入门课程，User-Centered Methods for Product and Service Design 这门课是我来这边接触的第一门和HCI相关的课程，一开始就给了9篇文章让我们对这个领域有一个初步的认识。由于初次接触HCI领域的文章，阅读报告中的内容和原文肯定会有理解上的出入，欢迎各位在评论区斧正。

第一篇报告是一个European Standard，我计划将重点放在Human-centred desingn的背景上面。

1、2、 3 Introduction

该标准对Human-centred design的定义如下:

Human-centred design is an approach to interactive systems development that aims to make systems usable and useful by focusing on the users, their needs and requirements, and by applying human factors/ergonomics, and usability knowledge and techniques. This approach enhances effectiveness and efficiency, improves human well-being, user satisfaction, accessibility and sustainability; and counteracts possible adverse effects of use on human health, safety and performance.

这个文档的目标是帮助设计开发硬件软件以涉及re-design processes的人能够更好的辨认并且高效的规划 human-centred design activities，它提供了human-centred设计领域的需求和建议。它可以被整合到各种不同的方法中，如object-oriented,、waterfall和rapid application development。

文档定义了一些名词，以下记录几条我认为比较有用的:

• context of use

  combination of users, goals and tasks, resources, and environment(

  (The “environment” in a context of use includes the technical, physical, social, cultural and organizational environments.)

• ergonomics, human factors

  scientific discipline concerned with the understanding of interactions among human and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance

• prototype

  representation of all or part of an interactive system, that, although limited in some way, can be used for analysis, design and evaluation

  (A prototype may be as simple as a sketch or static mock-up or as complicated as a fully functioning interactive system with more or less complete functionality.)

• stakeholder

  individual or organization having a right, share, claim or interest in a system or in its possession of characteristics that meet their needs and expectations

• usability

  extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use

• user experience

  user’s perceptions and responses that result from the use and/or anticipated use of a system, product or service

  (Users’ perceptions and responses include the users’ emotions, beliefs, preferences, perceptions, comfort, behaviours, and accomplishments that occur before, during and after use.)

  (User experience is a consequence of brand image, presentation, functionality, system performance, interactive behaviour, and assistive capabilities of a system, product or service. It also results from the user’s internal and physical state resulting from prior experiences, attitudes, skills, abilities and personality; and from the context of use.)

4 Rationale for adopting human-centred design

采用human-centred的设计有非常多好处(诸如提高效率，延长产品使用时间，降低训练用户使用以及维护成本等)，下表给出了使用human-centred设计的例子

5 Principles of human-centred design

文档总结了六点需要遵守的原则:

The design is based upon an explicit understanding of users, tasks and environments

如标题，举例为在手机上给年轻人体验非常好的听音乐app的交互界面有可能完全不适合在个人电脑上使用，设计师要考虑context of use。

Users are involved throughout design and development

用户要积极的参与开发的过程，具体可以为直接参与设计，成为相关数据的来源或者结果评估方，这些用户需要满足产品预期用户匹配的特点。

当开发定制的产品时，预期用户和执行的任务可以直接与开发过程联系起来。使用系统的组织有机会在设计出现时对其产生直接影响，而那些实际将与未来系统一起工作的人可以参与评估所提议的解决方案。这种参与和参与还可以提高用户的接受度和忠诚度。

当开发通用产品或消费产品时，用户群体是分散的，产品可以针对具有特定特征的用户群体。用户或适当的代表参与开发仍然很重要，以便能够确定与预期用户组相关的用户和任务需求，以便纳入系统规格书，通过测试拟议的设计解决方案提供反馈。

The design is driven and refined by user-centred evaluation

用户的反馈非常重要，及时的应对反馈能够有效缩短理想和现实差距

The process is iterative

即在满足特定要求前反复的执行重复的流程。在HCI领域不可能在开始就能够把所有的细节准确把握住，在迭代的同时通过新的反馈可以不断完善。

The design addresses the whole user experience

用户体验是交互系统的表示、功能、系统性能、交互行为和辅助功能的综合体现的结果，用户的经历、态度、技能，习惯以及性格同样会影响用户体验。

The design team includes multidisciplinary skills and perspectives

总结如下:

6 Planning human-centred design

Responsibility

在设计时要考虑一下三点:

• userbility 与产品的用途，系统和服务之间的关系 (e.g. size, number of users, relationship with other systems, safety or health issues, accessibility, specialist application, extreme environments)
• poor usability 可能造成的结果 (e.g. financial, poor product differentiation, safety, required level of usability, acceptance)
• the nature of the development environment (e.g. size of project, time to market, range of technologies, internal or external project, type of contract)

Content of plan

7 Human-centred design activities

这一章的篇幅最长，感觉也是最重要的。当确定下来设计/开发产品/服务的目的后需要做的工作如下:

• 7.2 理解并确定 context of use (Understanding and specifying the context of use)

• 7.3 确认用户的需求 (Specifying the user requirements)

• 7.4 提供设计方案 (Producing design solutions)

• 7.5 评估设计 (Evaluating the design)

同时，Human-centred design 可以从上述四个步骤中任意一点开始。

值得注意点是，同一个产品可能会被有不同需求的用户群体使用，不同用户以及任务之间的context of use的差距也可能非常大。一些用户的需求可能在设计能提供针对特定问题的解决方案时才会出现；不同用户对设计的需求可能会互相冲突。

整个流程如下:

7.2 Understanding and specifying the context of use

7.2.1 General

用户的习惯、任务以及组织的、技术的、物理的环境决定了system用的contex。

7.2.2 Context-of-use description

A context-of-use description can be a description of the current context of use or a description of the context intended for design

需要包含：

• The users and other stakeholder groups

• The characteristics of the users or groups of users

• The goals and tasks of the users

• The environment(s) of the system

7.2.3 Sufficient detail to support design

细节可能无法一次完全确定，需要在开发的过程中不停的审视，维护和更新。

7.2.4 Context of use specified for design

应在用户需求规范中说明设计用于设计的使用context(即使用系统的contex)，以清楚地确定要在不同需求下的条件。

7.3 Specifying the user requirement

7.3.1 General

In most design projects, identifying user needs and specifying the functional and other requirements for the product or system is a major activity. For human-centred design, this activity shall be extended to create an explicit statement of user requirements in relation to the intended context of use and the business objectives of the system.

Depending on the scope of the system, the user requirements can include requirements for organizational changes and revised work styles and can suggest opportunities to combine products and services. If it is known that the proposed interactive system will affect organizational practice, the development process should involve organizational stakeholders, with the aim of optimizing both the organizational and technical systems.

7.3.2 Identifying user and other stakeholder needs

如题，包括了哪一些用户需求需要满足(而不是怎么满足)context of use 设定的限制

7.3.3 Deriving user requirements

7.3.4 Resolving trade-offs between user requirements

诸如速度和准确性之类的需求可能会冲突，同时可能通过 revisiting initial assumptions 以及和需求提出放协商解决

7.3.5 Ensuring the quality of user requirements specifications

7.4 Producing design solutions

7.4.1 General

包含三个子过程

• Designing user tasks, user–system interaction and user interface to meet user requirements, taking into consideration the whole user experience
• Making design solutions more concrete
• Altering the design solutions based on user-centred evaluation and feedback
• Communicating the design solution to those responsible for implementation

7.4.2 Designing user tasks, user–system interaction and user interface to meet user requirements, taking into consideration the whole user experience

Principles for design

• 对任务适用
• self-descriptiveness (对于用户来说随时知道自己在哪个会话中，在会话的哪个 位置，可以采取什么操作，操作会有什么结果)
• 符合用户期望
• 适合学习 (suitability for learning)
• 可控性
• 鲁棒性 (error tolerance)
• 适合个性化 (suitability for individualization)

Designing the tasks and interaction between user and system

比较重要的一点是设计的时候还要考虑到使用者如何使用设计的工具完成任务，而不是让任务适应工具。

Designing the user interface

For the detailed design of the user interface, there is a substantial body of ergonomics and user interface knowledge, standards and guidelines which should be used to inform the design of both hardware and software. These include standards within the ISO 9241 series on displays, input devices, dialogue principles, menus, presentation of information, user guidance, and other user interface and accessibility guidelines. Many organizations also have internal user interface style guides, product knowledge and knowledge on users and other aspects of the context of use, such as user expectations (see ISO 1503) and stereotypes.

7.4.3 Making design solutions more concrete

简单的原型在探索替代设计方案的早期非常珍贵，注意不需要在原型上投入过度的精力完善细节以免后期修改困难。

7.4.4 Altering the design solutions based on user-centred evaluation and feedback

在早期评价的基础上提出的改变很可能是最具成本效益的。

7.4.5 Communicating the design solution to those responsible for implementation

有效的沟通方式包括提供合适的文档，提供修正后的原型等

7.5 Evaluating the design

7.5.1 General

有些时候让用户直接评估成本会很高甚至是不现实，需要通过如建模和仿真的方法进行评估。

User-centred evaluation 可以背用于:

• collect new information about user needs
• provide feedback on strengths and weaknesses of the design solution from the user’s perspective
• ** assess whether user requirements have been achieved (which can include assessing conformity to international, national, local, corporate or statutory standards)**
• ** establish baselines or make comparisons between designs**

7.5.2 Conducting user-centred evaluation

7.5.3 User-centred evaluation methods

项目的早期和后期都需要评估，分别使产品更符合需求以及检查是否满足需求。

可以通过基于用户的评价以及基于guidelines和requirements的评价。

7.5.4 User-based testing

可以存在于任何一个阶段

早期的testing可以了解设计的接受程度；当原型完成设计后，用户可以利用原型进行测试，产生的反馈信息反过来促进设计的改进；在开发的后期用户测试可以用来检查usability objectives, 检验是否满足了context of use.

7.5.5 Inspection-based evaluation

可以作为user testing的一个补充， 作为在user testing前解决主要问题的途径，可以有效降低后续user testing的成本。

Inspection-based evaluation 通常通过找usability相关方面一个或多个的专业人士基于先前项目的经验以及ergonomic的标准来进行评测。Inspection 可以通过测试人员站在用户的角度通过使用测试的产品/系统/服务进行，也可以通过以checklists, lists of user requirements, general usability guidance, industry best practices, usability heuristics, guidelines or standards等形式进行。值得注意的是，测试的结果会很依赖测试人员的专业水平。

和user-based testing比较，inspection-based evaluation更加灵活简单，可以覆盖的面积更广，并且两个方法所针对的问题可以不重合。 inspection-based evaluation更倾向于发现明显的表面问题，而且在复杂的或者全新的设计上效果可能会不尽如人意。inspection-based evaluation测试必须由专业高度相关的人参与进行否则结果会不可靠，有时候甚至需要相关细分应用领域的专家的参与。

7.5.6 Long-term monitoring

涉及到通过不同的方式在一段时间内收集用户的输入数据。

Follow-up evaluation is often a formal part of system evaluation and is carried out within a specific time frame, e.g. six months to a year after the system is installed. Follow-up evaluation often tests performance of the system and also collects data to determine whether user needs and requirements have been met and are correctly stated.

一些使用交互产品/系统或服务所产生的现象/效果可能不会马上出现，同时外部环境的改变如立法等也会使一些新问题出现。这些情况并不需要在开始阶段就完全解决，但是持续的信息收集仍旧对解决这些问题有一定帮助

8 Sustainability and human-centred design