Investigating The Iso Standards For Designing Interfaces

Published Date: 02 Nov 2017

ISO stands for the International Organization for Standardization. This is a network of national standards organizations from 147 countries around the world. It comprises of a groups of specialists, nominated by national standards committees, who are expected to act as independent experts. Their existence is to ensure the development and publication of a comprehensive range of International standards to support user-centered design, and the development of easy to use interfaces creating or imposing consistency. The ISO has a range of standards in different aspects all associated with the ergonomics of human system interaction. Much of the material in these standards represents the initiative of good practices. This paper is intended to investigate the two ISO standards for designing interfaces ( 9241and 16982) which relates to usability, giving definition, objective and examples of usability, usability considerations, aspects related to designing methods as well as aspects related to evaluation methods.

The term Usability can be defined generally as the eases of use in its simple form or a combination of concepts, such as execution time, performance, user satisfaction and learnability of a human made object. The object of use can be from software application to hardware devices or anything a human can interact with. Usability differs for each user through user experience because usability also considers usefulness. The ISO has different types of standards for usability they are categorized into four classifications. The objectives for these terms are, (1) the use of the product to be effective, efficient and satisfying when used in the intended contexts. This speaks about quality of use. (2) The user interface and interaction. Involves how communication between the user and the device is achieved. (3) The process used to develop the product. Relates to the different methods in how the product is accomplished. (4) The capability of an organization to apply user-centered design.(Figure1) This diagram is a logical representation of the relationship between the four classified terms.

According to the international standardization the two major standards that relates to usability can be distinguished as, product-oriented standards and process-oriented standards. The category in which, ISO 9421 and 16982 falls under is generally the process-oriented section. The ISO 9241 is aimed towards system developers, specifiers and purchasers of systems standard. It is a multi-part standard that covers a number of features for people working with computers. This is a collection of international standards on ergonomics requirements for the work place carried out using visual display terminals (VDTs), it has been renamed more broadly as Ergonomics of Human System Interaction. The definition of ISO 9241 derives from part 11of its series which is used in several related ergonomic standards. It states as follows "the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use". This terminology is put together from different usability perspectives. However its key components are effectiveness, which describes the interaction from a process perspective; efficiency, which pays attention to results and the resources involved; and satisfaction, which is a user’s opinion.

The general objectives of ISO 9421 from part 1 to part 17 are charted as:

Part 1: General Introduction (1997)

This is the introduction to the multi-part standard ISO 9241 for the ergonomic requirements for the use of visual display terminals for office tasks. It explains some of the fundamental principles. Guidance on how to use the standard as well as describes how conformance to parts of ISO 9241 should be reported

ISO 9241-2: Part 2: Guidance on task requirements (1992)

This gives guidelines on the designing of tasks and jobs involving work with visual display terminals. It provides guidance on how task requirements may be identified and specified within individual organizations and how task requirements can be incorporated into the system design and implementation process.

Parts 3–9 deal with physical characteristics of computer equipment, design requirements and guidance.

ISO 9241- 3: Part 3: (1993, deprecated) Visual display requirements

This part specifies the ergonomics requirements for display screens which ensure that they can be read comfortably, safely and efficiently to perform office task. Although it deals specifically with displays used in offices, it is appropriate to specify it for most applications that require general purpose displays to be used in an office-like environment.

ISO 9241-4: Part 4: Keyboard requirements (1998)

Specifies the ergonomics design characteristics of a keyboard which may be used comfortably, safely and efficiently to perform office tasks. Keyboard layouts are dealt with separately in various parts of ISO/IEC 9995: 1994 Information Processing - Keyboard Layouts for Text and Office Systems

ISO 9241-5 part5: Workstation layout and postural requirements (1998)

This specifies the ergonomics requirements for a Visual Display Terminal workstation which will allow a user to adopt a comfortable and efficient posture.

ISO 9241-6:part6: Environmental requirements (1999)

This states the ergonomics requirements for the Visual Display Terminal working environment which will provide the user with comfortable, safe and productive working conditions.

ISO 9241-7 Part 7: (1998, deprecated) Display requirements with reflections

This part specifies methods of measurement of glare and reflections from the surface of display screens, including those with surface treatments.

ISO 9241-8 Part 8: (1997, deprecated) Requirements for displayed colors

This part specifies the requirements for multicolour displays which are largely in addition to the monochrome requirements in Part 3.

ISO 9241-9: Part 9: Requirements for non-keyboard input devices (2000)

This contains the ergonomics requirements for non-keyboard input devices which may be used in conjunction with a visual display terminal. It also includes a suggestion for a user-based performance test as an alternative way of showing conformance. The standard covers such devices as the mouse, trackball and other pointing devices, but it does not address voice input

Parts 10 deals with a general set of usability heuristics for the design of different types of dialogue

ISO 9241-10: Part 10: Dialogue principles (1996)

This part deals with general ergonomic principles which apply to the design of dialogues between humans and information systems: suitability for the task, learning, and for individualization, conformity with user expectations, self-descriptiveness, controllability, and error tolerance.

Parts 11–19 deal with usability aspects of software, including Part 10. It is general guidance on the specification and measurement of usability.

Part 11: Guidance of usability (1998). Hardware and software usability

This part deals with the extent to which a product can be used by specified users to achieve specified goals. It includes an explanation of how the usability of a product can be specified and evaluated as part of a quality system. It also explains how measures of user performance and satisfaction can be used to measure how any component of a work system affects the quality of the whole work system in use.

Part 12: Presentation of information (1998)

This part contains recommendations for presenting and representing information on visual displays. It includes guidance on ways of representing complex information using alphanumeric and graphical/symbolic codes, screen layout, and design as well as the use of windows.

Part 13: User guidance (1998)

This part provides recommendations for the design and evaluation of user guidance attributes of software user interfaces including prompts, feedback, status, on-line help and error management.

Part 14: Menu dialogues (1997)

This part provides recommendations for the design of menus used in user-computer dialogues. The recommendations cover menu structure, navigation, option selection and execution, and menu presentation (by various techniques including windowing, panels, buttons, fields, etc.).

Part 15: Command dialogues (1997)

This part provides recommendations for the design of command languages used in user-computer dialogues. The recommendations cover command language structure and syntax, command representations, input and output considerations, feedback and help.

Part 16: Direct manipulation dialogues (1999)

This part provides recommendations for the ergonomic design of direct manipulation dialogues, and includes the manipulation of objects and the design of metaphors, objects and attributes. It covers those aspects of Graphical User Interfaces that are directly manipulated, and not covered by other parts of ISO 9241.

Part 17: Form filling dialogues (1998)

This part provides recommendations for the ergonomic design of form filling dialogues. The recommendations cover form structure and output considerations, input

Considerations, and form navigation.

An additional part which also applies across all of ISO 9241 is: Part 20 Accessibility and human-system interaction. The remaining parts are structured in ‘hundreds’ and gives a introduction of the section as follows: 100 series Software ergonomics 200 series Human system interaction process 300 series Displays and display related hardware 400 series Physical input devices - ergonomics principles 500 series Workplace ergonomics 600 series Environment ergonomics 700 series Application domains - Control rooms 900 series Tactile and haptic interactions

Whereas the ISO 16982, which is Ergonomics (human factor) of human-system interaction– Usability Methods Supporting Human-Centered Design. It is aimed for project managers and designers. This standard describes a range of methods for designing and evaluating computer-based systems and products for ease of use. This is reformed to the new ISO technical report: ISO/TR 16982:2002 which also gives pros and con of each usability method as well as examples of usability methods in there context. ISO 16982:2002 can be altered to specific design situations by using the lists of issues characterizing the context of use of the product to be delivered. This standard applies throughout the life cycle process (development process) of the system or product, including conception, design, implementation, support, use, and maintenance.

The objective of this ISO standard is intended to help project managers gain a better understanding of the situation, thereby enabling them to implement and plan effective and timely human-centered design activities. Also the expectancy to increase user satisfaction and productivity, decrease support, injuries and training costs, and improve user health and well-being

When designing for the best results of usability in user interfaces, there are several vital considerations that are needed to be obtain and applied in order to produce efficiency effectiveness and user satisfaction of an end-product. These concepts create the grounds or basis in which the end-product will be designed. The consideration can be in the form of questions based of the perception of the users. These questions should include who are the users, (for example female students between the ages 15-25) what will they use it for? (For example to obtain the rate of their heartbeat) Where will they use it? (For example at the gym) When will they use it? (After training sessions) How will they use it? (For example by making physical contact with the object, resting it on their chest) What do they know, what can they learn? (For example they know the machine will give a response, they can learn that their heart rate is high or low) What do users want? (For example they want immediate response of the rate of their heartbeats) What is the users' general background? (For example are the users disable in some form) what is the users' context for working? What must be left for the machine to do? Answers to these questions are very crucial and should be achieved at the initial stage of the designing process.

Not only does the process involve stages of consideration but it involves stages of evaluations. This can be broken up into two categories which are Usability evaluations, which typically do not include users working with the product and Usability tests, which focus on users working with the product. Many usability professionals first do a usability evaluation and then follow it up with a usability test. Usability evaluation can be conducted as soon as there is a sample the techniques require solid judgment from the evaluators and usually do not include representative users.

The results of the evaluation to develop hypotheses about what could be serious problems and then develop the usability test around those hypotheses. Usability testing is the only way to know if the product actually has problems that keep people from having a successful and satisfying experience. The evaluator should not be interested in what testers think will be a problem; but to understand the problems one or more users actually struggle with in aspect of the site. A usability test provides an opportunity for the site to allow users to succeed, succeed with difficulty, or totally fail. However some of the method which can be used for evaluation techniques include: surveys/questionnaires, observational evaluations, guideline based reviews, cognitive walkthroughs, expert reviews, and heuristic evaluations.

Another important aspect of usability is the designing process and the methods involved. Designing for usability involves the activities of creating user requirements for a new system or product, prototyping the user interface and testing it with representative users. According to Eberts (1994) there are four methods including:

1. The Anthropomorphic Approach, this method in-cooperates affordance, the potential action the users makes with an object and constraint, the limitation the user has with the object. It uses human-like qualities to create a friendly or human to human environment. For instance, Interface error messaging is often written this way, such as, "We’re sorry, but that page cannot be found." An example of an affordance can be the tone that indicate you have received a new message and the constraint can be an error message stating the message cannot be opened with a particular format followed by a warring tone which indicates the task cannot be completed

2. The Cognitive Approach considers the abilities of the human brain and sensory-perception in order to develop a user interface that will support the end user. This method has Metaphoric Design which uses metaphors can be an effective way to communicate an abstract concept or procedure to users, as long as the metaphor is used accurately. For instance, a user can move a file or folder into the "trashcan" to delete it.

Attention and Workload Models consider the user’s attention span, which may be based on the environment of use, and the perceived mental workload involved in completing a task. For example, when designing a web-based form to collect information from a user, it is best to contextually collect information separately from other information. The form may be divided into "Contact Information" and "Billing Information", rather than mixing the two and confusing users. By "chunking" this data into individual sections the perceived workload is also reduced

Human Information Processing model "Human Information Processing (HIP) Theory describes the flow of information from the world, into the human mind, and back into the world. When a human pays attention to something, the information first gets encoded based on the sensory system that channeled the information (visual, auditory, haptic, etc.). Next, the information moves into Working Memory, formerly known as Short-Term memory. Working Memory can hold a limited amount of information for up to approximately 30 seconds. Repeating or rehearsing information may increase this duration. After Working Memory, the information may go into Long-Term Memory or simply be forgotten. Long-Term Memory is believed to be unlimited, relatively permanent memory storage. After information has been stored in long-term memory, humans can retrieve that information via recall or recognition. The accuracy of information recall is based on the environmental conditions and the way that information was initially encoded by the senses. If a human is in a similar sensory experience at the time of memory recall as he was during the encoding of a prior experience, his recall of that experience will be more accurate and complete."

3. The Empirical Approach is useful for examining and comparing the usability of multiple conceptual designs.

Human Task Performance Measures and A/B testing: measuring users’ task performance is important for determining how intuitive and user-friendly a product is. For instance, it may have been determined that users should be able to register for an account within five minutes, and with no more than two errors. If the researcher observes otherwise, and even if the user finally completes the task (perhaps after fifteen minutes and five errors), the time and number of errors may be compared to the desired standard as well as to the alternate conceptual design for the product.

4. Predictive Modeling Approach: Goals, Operators, Methods, and Selection Rules (GOMS). It is a method for examining the individual components of a user experience in terms of the time it takes a user to most efficiently completes a goal. For example, the average time it takes a human to visually fixate on a web page, move eye fixation to another part of the web page, process information, and make a decision of what to do next can be measured in milliseconds

One or more of these approaches may be used in a single user interface design depending on the product.

In conclusion making interactive systems more human-centered has substantial economic and social benefits. There are standard required for usability which state effective and efficient ways and methods for creating user-centered designs. These standards are there to ensure user satisfaction and user safety creating a comfortable environment to perform operations. However failing to comply with these standards can be very costly and pose a great risk to both a user and an organization. As a designer it is important to consider the users because in disobeying these standards or ignoring them it can negatively affect the user for example causing physical injuries. Negative effects on how useful the object or software really is, can occur as well. For example the Microsoft calculator-no multiplication and what does the asterisk do? But these issues can be limited or even prevented by simply gathering the relevant standards required for the project and adhering to them.