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Have you ever considered the importance of the design of an interface? The study and application of human computer interaction (HCI) and human factors is very important and can actually save lives. For example, interfaces that allow nurses to type in the digits of a drug dose are much more dangerous than the interfaces that force the nurse to dial the dose in using a wheel for each digit. When typing, a repeated digit can increase the dosage of medication by a factor of ten and can result in severe complications or even death to the patient. This mistake is not possible with the other dial-based interface.

In 1989 in the Kegworth airplane disaster, forty-seven people lost their lives due to poor HCI and human factors work. This crash of a Boeing 737 was, in part, caused by poor cockpit and instrument design. The study and application of HCI and human factors can also save money. One example is the New York telephone company (Nynex) case. In the early 1990's Nynex considered upgrading their system. They believed that the new graphical user workstations could improve productivity. Just to be safe, they had an analysis done before implementing the system. The analysis found that the new system would in fact be four percent slower. That seems like a small amount, but the four percent loss in productivity was going to cost Nynex $2.4 million a year! Understanding the user is key to these issues.

After reading this topic, you should be able to:

• Describe the basic principles of human factors and the importance of ergonomics and anthropometrics.
• Discuss the role and importance of human factors and human computer interaction.
• Describe some basic principles of user centered interface design.
• Outline some elements of usability testing and systems evaluation.

Ritter, F. E., Churchhill, E., & Gilmore, D. (2003, Spring). Introduction to the user: the ABCs of user interface design. Unpublished manuscript.

Lesson Objectives

Human factors work is critical for the successful implementation of information technologies. Unless human characteristics are considered when designing systems, the results can be loss of productivity and resources. Poorly designed interfaces impact performance. Human cognitive capabilities should be considered in the design of a system. Ergonomics and anthropometrics issues appear everyday in the media. The consequences of human factors work are profound.

After reading this lesson, you should be able to:

• Identify the characteristics of human factors and human-centered design.
• Describe anthropometric user characteristics.
• Identify the characteristics of ergonomics.

Human Factors

Information technologies are used in the real world in offices, homes, factories, and industries. Human factors work is concerned with the design, usability, learnability, and functionality of systems designed for human use. Unless human characteristics are considered when designing or implementing technologies, the consequences can be errors and a lack of human productivity. Human factors workers are concerned with important health and safety issues in work environments that include technology.

Human factors work involves assessing how something is used to see if it can be made quicker, safer, and more productive, looking at mistakes that are made when using technologies to see how they could be prevented, and assessing which tasks can effectively be performed by humans or machines.

Historically, many technologies have not been designed with users in mind. Many technologies do not fit users' tasks. Technology systems need to be built to effectively support human tasks. Failing to design and develop information technologies with user characteristics in mind can lead to a lack of system functionality, increase in user dissatisfaction, and increase in ineffective work practices. For example, poorly designed and inappropriately placed interfaces in fast-food restaurants, such as McDonald's and Wendy's, can decrease worker efficiency, increase poor customer service, and increase costs for the company.

Human factors workers examine individual differences in a technology-user's behavior and performance that have design implications. Workers with human factors training understand the importance of looking at both people and systems, as they work together. Information technology must account for human levels of attention, learning, communication styles, and memory. For example, in fast food restaurants, workers enter the customer orders into the computer. Direct customer ordering through touch screen can lead to more accurate orders and fewer errors. Examples of this are the MTO (Made-To-Order) screens in Sheetz convenience stores and the self-checkout screens at some supermarkets.

Human factors workers integrate knowledge from multiple disciplines to design better technologies. Research from engineering, anthropology, sociology, social psychology, mathematics, cognitive psychology, and linguistics is used in human factors work. Human factors work and research involves the collection of the data and the evaluation of different designs. The following factors affect design - physical, perceptual, cognitive, social, and historical. The results of human factors work are important and applied in many different industries and work environments, such as the design of computers, cars, airplanes, industrial machinery, military vehicles, office environments, consumer products design, and manufacturing. An example is designing a car for safety with the goal of limiting passenger injury in a crash. These designs need to be tested. How human factors work is used in organizations depends upon the available time and resources, the system that is being designed, and the intended users.

Some related links:

• Human Factors and Ergonomics Society - This international society promotes the discovery and exchange of information about the characteristics of humans that apply to the design of systems.
• Centre for HCI Design - An independent HCI-related research group within the School of Informatics at London's City University.
• University of Maryland HCIL - Human Computer Interaction Lab.
• NASA - Human Factors Research and Technology Division.
• Car Interface: Cadillac interior - Take a look at a Cadillac interface

Human Cognitive Capabilities

Human factors workers must also take account of human cognitive capabilities, such as memory, attention, and learning ability that vary between users. Humans have four types of memory: iconic, short-term, working, and long-term.

1. Iconic memory: This very short term memory includes images left in memory when a user closes their eyes.
2. Short-term memory: A temporary memory store where information decays over time.
3. Working memory: A temporary memory store that includes refreshing or reusing the information.
4. Long-term memory: A memory that is permanently encoded with longer more permanent memories.
5. In addition, memory can be classified as declarative memories that include facts or statements about the world and procedural memories that are used to perform procedures. More specifically, implicit memories are not reportable and explicit memories can be reported. Human factors workers must also consider human learning abilities and how to design information technologies to support different learning styles.

Human factors workers must keep human limitations in mind when they are designing technologies. For example, if a person needs to enter a phone number in their Contacts, they store the number in short term memory. The short term memory limitation is generally "five plus or minus two" items, just enough for the typical US phone number.

Human cognitive capabilities should be considered in the design of a system. For example, human cognitive capabilities should be considered in the design of a web search history application, so that when the user is searching the web and they use the search history to help them remember what they previously had searched, the results are successful. Human factors work influences the design of systems. An example is the navigation system in a car assisting the user in successfully reaching their destination.

Human factors workers are concerned with vital issues in the technology workplace. Human limitations, the shape of the human body, and how the shape of the human body influences the design of systems must be considered. If industries, including airlines and nuclear power plants, do not consider human factors issues, then the public's safety is jeopardized.

Wrap-Up

Now that you have completed this lesson, you should be able to:

• Identify the characteristics of human factors and human-centered design.
• Describe anthropometric user characteristics.
• Identify the characteristics of ergonomics.

Additional Human Factors Reading:

Norman, D. (1988). The psychology of everyday things. NY: Basic Books.

Lesson Objectives

Human computer interaction (HCI) is a growing field of study. Models assist HCI workers in decision making. This lesson describes two well known HCI models. Good human computer interaction work and design leads to favorable results including increasing worker productivity and satisfaction, reducing costs, and reducing errors. Good HCI is clearly imperative to a successful design process.

After reading this lesson, you should be able to:

• Identify the characteristics of human-computer interaction.
• Identify behavioral and cognitive user characteristics.

Human computer interaction (HCI) is the study of human interaction with computer interfaces and the development of computer based interfaces to support effective user-computer tasks and interaction. Human computer interaction work involves the detailed study of users' tasks, goals, and behaviors when using computer systems and interfaces.

HCI workers develop new computer applications and interface, and then test and evaluate new interactive computer devices and interfaces. For example, when designing a Web search engine interface, an HCI worker seeks to understand how users look for information on the Web, how users decide what action to take, and what information do users need to plan a strategy for performing the task.

HCI workers must decide what information users need to perform a HCI task. They also consider the cognitive effort involved in a task (the number of mental transformations), how to display information on a computer interface so that it is most comprehensible and perceptible to the user. For example, HCI workers examine how to design more effective word processors and Web search engines.

HCI Model: Foley

Foley (1980) provides a comprehensive HCI model that includes the following four levels:

The first stage is the conceptual level understanding of the user's mental model of the HCI task. Users may have different mental images of the HCI task. For example, users have very different mental pictures of the Web. If you ask people to draw a picture of the Web, these pictures might include the following very different representations: hierarchy, telecom, library system, network, and 3-D web. Another example is that some users equate using a word processor with a typewriter interaction; a computer keyboard is similar to a typewriter keyboard.

The semantic level understanding includes the meaning of the user's input to the computer and the computer's output to the user. The input-output feedback loop between user and system only works effectively if the computer understands the user's input and the user understands the system's output. This can be a problem if the system's output is culturally based. For example, Americans understand the "trash" icon, but the British use the word garbage and may not understand the "trash" icon.

In the syntactic level, there is an understanding of how the words used are assembled into meaningful sentences that instruct the computer to perform a certain task. HCI works well when users can express their needs in meaningful sentences to the computer. For example, users often have problems expressing their information need to a Web search engine.

The fourth level, the lexical level, includes understanding user's mechanisms when structuring their interaction with the computer. A user's interaction with a computer is structured by the person who developed the interface. If the interface does not allow the user to structure their interaction in a user friendly way, the system interaction may not be satisfactory. For example, when looking for information, people often ask questions of other people. Many Web search engines do not allow the user to ask the computer a question in natural human language or conversation style. A classic site that does allow questions is the Ask Jeeves site.

Norman (1988) provides the following goal-oriented staged model of user's interaction with a computer:

1. Forming the goal of the HCI interaction: User's interact with a computer to solve a problem or achieve a goal. For example, a user's goal may be to find information about motor boats by using a Web search engine.
2. Forming the intention of the HCI interaction: Having established a goal for their interaction with a computer, users must form an intention to use the computer.
3. Specifying the HCI action to be performed: An interface must clearly specify the actions users need to perform. For example, if the user does not clearly understand the correct commands or instructions to conduct an interaction with a Web search engine, their HCI interaction may fail.
4. Executing an action with the computer: A user's HCI interaction must be error free and achieve the correct action. For example, the interface must provide effective help systems.
5. Perceiving the systems state through feedback: The computer output must be in a form that the user is able to see the feedback. System responses must be visible and readable by the user. The size of text and images must be large enough to read.
6. Interpreting the systems state through feedback: The computer output must be in a form that the user is able to understand the feedback. System responses must be comprehensible and understandable by the user. Many computer responses to users input are incomprehensible and are often ignored by users.
7. Evaluating the systems output: Users must be able to evaluate the systems output correctly and effectively. For example, most Web search engines display the results of a user's query as a list of Web sites. Frequently, users do not understand the structure of this Web site list, and how it is ranked and determined by the system.

Good HCI Work and Design

Solid HCI work serves as the foundation to obtaining the following results. Good human computer interaction work and design is important for obtaining these measurable outcomes:

• Increasing worker productivity
• Increasing worker satisfaction and commitment
• Reducing training costs
• Reducing errors during interface interaction
• Reducing production costs

Increase in Worker Productivity, Satisfaction, and Commitment

Good human computer interaction work and design is important for increasing worker productivity. If workers have problems using computer interfaces, due to poor design, their work effectiveness can be reduced. Effectively designed interfaces that offer customization for users can increase user's work satisfaction. For example, a military fighter plane must have highly effective HCI interfaces to allow pilots to make quick and effective decisions and actions.

Good human computer interaction work and design is important for increasing worker satisfaction. Improved interfaces design can lead to increased worker satisfaction and allow users to achieve their work goals.

Good human computer interaction work and design is important for increasing job commitment by reducing worker turnover. Poor quality interfaces can lead to stress and strain on users both mentally and physically. Users may experience sore muscles or eye strain due to poor HCI interfaces and computer design. Workers may leave their jobs if they are dissatisfied with their HCI experience.

Reduction in Training Costs, Errors, and Production Costs

Good human computer interaction work and design is important for reducing training costs. Poor HCI interfaces may require extensive and expensive user training. Good interfaces with effective online or manual training documents and user system guides can help users to master their system interaction quickly. For example, commercial pilots learn to fly airplanes using computer-based cockpit simulators.

Good human computer interaction work and design is important for reducing errors during interface interaction. Effective interfaces and user training can reduce errors in system use. For example, an effective retail interface can reduce the time taken to complete a sale. Also, most of the problems that led to the Pennsylvania Three Mile Island nuclear power plant disaster were due to poorly designed computer systems.

Good human computer interaction work and design is important for reducing production costs. Effective interfaces allow workers to produce better quality products and services. For example, an effective Website can assist users to view products and services offered by companies, including better customer services.

Lesson Wrap-Up

Two classic models of HCI help us recognize the behavior and needs of users. The Foley model of HCI provides four levels of user understanding. The Norman model of HCI provides a goal-oriented staged model. As you now know, good HCI is important for obtaining measurable outcomes. Well designed computer interfaces can save time, money, and lives. Airline pilots, for example, need well designed computer interfaces to successfully accomplish their jobs.

Now that you have completed this lesson, you should be able to:

• Identify the characteristics of human-computer interaction.
• Identify behavioral and cognitive user characteristics.

Additional Human-Computer Interaction Readings:

Carroll, J. M. (Ed.). (2003). HCI models, theories, and frameworks towards a multidisciplinary science. San Francisco: Morgan Kaufmann.

Dix, A., Finlay, J., Abowd, G., & Beale, R. (1999). Human-computer interaction. (2nd ed.) London: Prentice Hall.

Foley, J. D. (1980). The structure of interactive command languages. In R. A. Guedj, P. ten Hagen, F. R. Hopgood, H. Tucker, & D. A. Duce (Eds.), Methodology of interaction (pp. 227-234). Amsterdam: North-Holland.

Morville, P., & Rosenfeld, L. (2002). Information architecture for the world wide web (2nd ed.). Sebastopol, CA: O'Reilly.

Norman, D. A. (1988). The psychology of everyday things. New York: Basic Books.

Lesson Objectives

Good interface design has significant positive results. High-quality design is a process which requires knowledge of systems design processes and user characteristics, such as users' physical characteristics, limitations, and motivations. Interfaces should be designed with simple, balanced, and consistent screens.

After reading this lesson, you should be able to:

• Describe approaches to interface design.
• Identify types of interfaces.
• Describe the process of iterative design and prototyping.

Interface Design

Many information technology interfaces are poorly designed. Many people are not able to use interfaces effectively due to poor design. Good interface design is important for reducing costs, errors, additional training, and employee turnover; and increasing user satisfaction, productivity, and quality products and services.

Good interface design requires diverse knowledge of systems design processes and user characteristics, including:

• Users' physical characteristics, limitations, and disabilities.
• Speed and efficiency needs.
• Reliability issues.
• Security concerns.
• Level of usability and functionality required.
• Frequency of product use.
• Users' past experience with same or similar product.
• Level of cognitive or mental effort required from the user.
• Users' tolerance for error.
• Users' patience and motivation for learning.
• Cultural and language aspects.

Good Interface Design

Good interface design requires diverse knowledge of systems design processes and user characteristics, including:

• Users' physical characteristics, limitations, and disabilities: Interface designers need to understand the characteristics of their users. For example, an Automatic Teller Machine (ATM) interface must be accessible by elderly, young, and disabled bank customers.
• Speed and efficiency needs: Many interfaces need to be quickly accessible and effective. For example, military pilots must have cockpit interfaces that allow quick and efficient interaction.
• Reliability issues: Interfaces that affect human lives need to provide reliable and readable information. For example, if an interface is provided information in a nuclear power plant system or a hospital operating room, the data quality and presentation needs to be accurate and reliable.
• Security concerns: Interfaces must have effective security and access mechanisms as required by an organization. For example, a bank Automatic Teller Machine (ATM) must allow bank customers to securely access their accounts and also keep out potential hackers.
• Level of usability and functionality required: Interfaces for users with little computing experience are more simply structured than interfaces designed for expert level users. For example, many interfaces offer advanced options and features for more expert users.
• Frequency of product use - Interfaces in high use computer systems need to be more reliable and effective to cater for fast interaction and a variety of users. For example, a bank Automatic Teller Machine (ATM) is used by hundreds of customers every day. The interface must allow for quick and effective interaction.
• Users' past experience with same or similar product - Many interfaces and systems provide similar features. For example, many bank Automatic Teller Machines (ATMs) provide identical functions and use similar banking terminology. The concepts of "withdrawal" and "deposit" that appear on ATM interfaces are familiar to bank users.
• Level of cognitive or mental effort required from the user - Many complex computer packages require a high level of financial or accounting knowledge. For example, the interface to the Quicken software requires knowledge of financial practices and accounting methods.
• Users' tolerance for error - Many interfaces allow users to complete actions with serious consequences when errors occur. For example, in a hospital emergency room, the medical computer interfaces need to be accurate, reliable, and without error, or patients may die.
• Users' patience and motivation for learning - Many interfaces are designed to allow users effective interaction with little learning required. For example, bank Automatic Teller Machines (ATMs) are simple menu systems that are designed to allow quick and easy learning.
• Cultural and language aspects - Interface designers must take account of users' cultural and language differences. For example, many interfaces that are designed for users in the multicultural United States society provide interaction in English, Spanish, Chinese, or other languages.

Scenario

One example of an interface redesign is from case study done at a fitness center with a touch screen interface on a Fitness Track machine. The usability problems included the button size was too small, the font size was too small, and multiple screen touches were entered by accident. These issues were resolved by observing the usability problems and creating solutions that addressed the problems. The users' physical characteristics and limitations had not been considered in the original design. This interface should have been designed with non-technology users' limitations in mind. To solve the problems, button size was increased, font size was increased, and a delay was added to the response of the button, so that repetitive touches of the screen were treated as one touch of the screen. The interface design was also simplified. These solutions enhanced the usefulness of the Fitness Track machine.*

*Stumpfhauser, L. & Chaparro, B. (2001). Designing a touch screen kiosk for older adults: a case study. Retrieved on August 12, 2003 from http://psychology.wichita.edu/ surl/usabilitynews/3W/kiosk.htm

User Centered Design

User centered participatory design involves the inclusion of users input into each phase of the user centered design process, including the user walkthrough and approval of each interface feature of a systems prototype.

User centered design involves the identification and consideration of relevant human factors in the design, evaluation, and implementation of information technology interfaces.

Displays should be readable (consider size, position, and ambient lighting) with differentiate and consistent displays (by shape, color, position, and size) that are compatible with the task to be performed.

HCI Design Process

The steps in the HCI design process can include the following steps:

1. Analyzing the users and determining their needs.
2. Drafting an initial design based on the users' needs analysis.
3. Testing the initial design with users in an HCI testing laboratory or in a real user work environment.
4. Developing a prototype system based on the initial design and users' feedback.
5. Testing the prototype system with users in an HCI testing laboratory or real user work environment.
6. Designing and refining each specific interface and screen.
7. Testing the interface with users in an HCI testing laboratory or a real user work environment.
8. Refining the interface based on users' feedback.
9. Implementing the interface.

Lesson Wrap-Up

As you now know, there are specific steps and tasks that a HCI worker would do in the process of completing a user centered participatory design. Do not forget about providing system updates and maintenance to the design. Sensitivity to user characteristics, including disabilities, is important in making your interface accessible by all users.

Now that you have completed this lesson, you should be able to:

• Describe approaches to interface design.
• Identify types of interfaces.
• Describe the process of iterative design and prototyping.

Additional User Interface Design Reading:

Schneiderman, B. (1998). Designing the user interface: Strategies for effective human computer interaction. Reading: Addison Wesley Longman.

Discussion Activity Assignment

Conduct a real-world observation of people using a system such as an ATM machine, Lion Cash machine, or Swipe card machine for doors. Write a report describing the system. Make sure to include a description of the interface, the functions of the system, the social environment of system, and your observations of people using the system. Also include at least one picture of the interface. Observe for 30 minutes, but do not talk to the users. You should only make observations. Be sure not to jeopardize users' security by observing too closely. Post your reaction below as a comment.

Lesson Objectives

Usability testing and evaluation is a vital discipline. Testing should be done early and often in the design process. It can providing the designers with feedback on user satisfaction and find errors in the systems design in a timely manner.

After reading this lesson, you should be able to:

• Identify the attributes of usability.
• Describe approaches to usability testing and evaluation.

Usability

An important part of the user centered design process is the incorporation of usability testing during both the design and evaluation stage of the systems or interface development. Usability refers to how easy an information technology is to use. Useful information technologies must be functional, useful, and learnable by humans.

Usability testing is important for:

1. Demonstrating the strengths and weaknesses of a design process and product. Usability testing includes collecting data that can be used to improve and redesign the interface.
2. Evaluating the overall design and specific system features. For example, HCI workers may test if users prefer a command line or menu interface.
3. Assessing the functionality of the system for a particular organization or set of users.
4. Validating the effectiveness and efficiency of the system, including potential productivity gains.
5. Providing the system designers with feedback on user satisfaction.
6. Identifying errors or mistakes in the systems design.

Usability Testing

Usability workers systematically and iteratively test each aspect of the system to improve systems design. Usability testing is a key part of iterative design techniques.

Systems are tested to see whether they fulfill the user's goals and provide feedback to the user on their actions taken and results. Every system or interface developed by industry involves some level of usability testing. Many industry accidents occur due to poorly designed information technologies.

The goal of usability testing is also to identify users' problems with the system, enable the users to provide the systems designers with feedback, and evaluate the performance of the system.

Formative and Summative Evaluation

Usability testing can occur at any time during the design process. User testing should be done early and often with real users.

There are different approaches and terms relating to user testing:

Formative evaluation: This occurs in order to assist IT designers in forming and refining their designs. Specific problems are identified during the design process. This is part of the iterative design process. The formative evaluation stage could include a think-aloud session where the user verbalizes their thoughts, choices, and questions to the evaluator. Evaluation is more likely to be done in person with direct observation. Video or audio recording of the user's interactions may be done.

Summative evaluation: This follows usability testing. The overall effectiveness and impact of the system is summarized. This may include a test between two or more alternatives. Statistical differences between features may be summarized and compared. Evaluation may be done remotely.

Alpha Testing: This usually is internal testing. The prototype that is developed is evaluated by internal users.

Beta Testing: This is usually available to external users. The prototype is made available to be evaluated by external users.

Usability Testing Tasks

Usability testing tasks include:

1. Analyzing users' interaction with the system, for example, users' keystrokes and interaction history, eye movements, and patterns of use.
2. Conducting experiments in which users perform system interaction tasks and think aloud (talk out loud about their actions and tasks) as they interact with the system.
3. Measuring the time users take per task, their error rates, and their level of satisfaction with the system.
4. Recording users' interaction with the system via paper forms, audio taping, or video taping to examine users' problems, errors, or interaction effectiveness.
5. Surveying users using a questionnaire or interview regarding their satisfaction with the system.

Usability testing includes the ethical concerns of respecting a user's mental and physical well-being and privacy. Evaluation workers must obtain the informed consent of volunteer participants before beginning usability testing. Usability workers must also be concerned not to bias users when conducting evaluation testing.

Lesson Wrap-Up

As you now know, usability testing is performed to answer questions and find problems before the consequences are significant. The investment of time and resources to usability testing and evaluation is well worth it.

Now that you have completed this lesson, you should be able to:

• Identify the attributes of usability.
• Describe approaches to usability testing and evaluation.

Usability Additional Readings:

Krug, S. (2000). Don't make me think: A common sense approach to web usability. Indianapolis: New Riders.

Neilsen, J. (2000). Designing web usability. Indianapolis: New Riders.

An important part of the IST perspective draws on theoretical and application areas from human factors and human computer interaction. The IST perspective includes consideration of how humans design, evaluate, implement, and use information technology.

Now that you have completed this topic, you should be able to:

• Describe the basic principles of human factors and the importance of ergonomics and anthropometrics.
• Discuss the role and importance of human factors and human computer interaction.
• Describe some basic principles of user centered interface design.
• Outline some elements of usability testing and systems evaluation.