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1 - Basic Concepts Human-Computer Interaction or Interface This course deals with the interaction between a user and information systems - or more generally tools for some purpose We deal with human and computer qualities. What are the basic properties of human beings that make it easy or difficult to deal with computers and what are the tools and techniques that are used in building software or information systems Furthermore, we take a look at design tools that can be used in creating systems that are easy to use in performing specific tasks. Definition according to ACM: Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them. In the early days of computing the computers were separated from the work of people who used the output of information systems of produced data for the information systems. The interface for the system was merely the forms for collecting data and the design of the printout forms. Modern information systems and software tools are an essential part of most work settings. The interface is also a tool to be used by the workers.

Terms User Interface, Man-Machine Interface (MMI) Those aspects of the system that the user comes in contact with (Moran, 1981) - an input language for the user, an output language for the system and a protocol for interaction Human-Computer Interaction (HCI) A set of processes, dialogues, and actions through which a human user employs and interacts with a computer (Baecker and Buxton, 1987) Human-Computer Interaction (HCI) A discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them (ACM SIGCHI, 1992)

HCI: A Multi Discipline Subject HCI draws attention from different fields. Apart from Computer Science, Electronics and IT, it draws attention from several other fields like Cognitive and behavioral science, Human factors, some empirical studies, Interface device development, Graphical design and lots more. • • • • • •

Computer Science Artificial Intelligence Linguistics Philosophy Sociology Anthropology

• • • • • •

Design Engineering Ergonomics and Human Factors Social and Organizational Philosophy Cognitive psychology Many more

Two views 1. 2.

System and interface as separate units (Interface as "Surface") Systems suitable for some task (Design Task)

The measure of good design • • • •

Technologically advanced affordable system Satisfied - motivated user Makes possible good job design or is part of a good task Supports organizational goals

In case of poor design the problem might be in the interface or in the system functionality Think of some household device (TV, Video, Doorbell, and Coffee Machine). Try to identify their interface and functionality and think what could be wrong with them.

Two basic concepts: Visibility and Affordance Donald Norman uses concepts visibility and affordance in describing general goals in user centered design. Visibility

All necessary controls should be visible for the user whenever he/she is supposed to be able to use them Affordance

Technical term that refers to the properties of objects - what sorts of operations and manipulations can be done to a particular object (Norman). The appearance of the controls should suggest the way they are to be used (pulled, pushed, slided, checked, dragged, dropped …) and what will happen if you use them.

Exercise: What is the role of visibility and affordance in the following systems and why: • • • • •

Mobile phone Bank automate - teller machine Company’s payroll system Library’s search system E-Market

The User in HCI Who is the user?

Casual user:

Knows only the basic techniques at the interface. Must be able to use the system right the first time.

• • •

Regular user: Professional user: Developing user:

Uses the system regularly, but not an expert Uses the system as a part of the job works with the system. Uses the system to construct the working environment.

The system should be developed and evaluated in the user context. Some systems have several different user groups. The user can be in different category using different systems.

Which user class?

• • • • •

Mobile phone user Vending/ Transaction machine E-Shopper CAD-designer Cashier

Context of HCI 'Applications' means any types of employing computers in our everyday activities. These Applications and the extent to which the interface fits them can have a profound impact (deep reflection) on every part of the HCI and its success. The research in HCI has originated in technical tools and programming details. At the moment a more wide perspective is taken in the HCI research. Main topics are group-work, effects on work, individuals, integration techniques and tools.

The discipline of HCI

Notion of Human Here Human is actually an end-user who actually uses a particular interface. This user has characteristics including: •

What computer interfaces he/she is comfortable with. (Having used them before or because of their inherent simplicity)

His/her technical expertise and degree of knowledge in specific fields or disciplines, and

Any other information which is believed to be relevant in a specific project

In HCI the word human is used in different flavors as follows: •

Classical user: Having a general knowledge on usage of computer by gathering experience over previous exposure. •

Specialized user: Having little or no background of computers. •

Example: One who uses ATM or a disabled person using particular software

Group of users: More than one user interacting over a software •

Example: Students, Bank manager

Example: two users having a conversation over a web-based application like a messenger

Organizations: Computer Aided Communication and cooperation among humans •

Example: Banking software.

Notion of Computer Computers are generally in the form of desktop PCs or workstations. Instead of workstations, computers may be in the form of embedded computational machines, such as parts of spacecraft cockpits or microwave ovens. A robot can also be a computer to whom we give commands and expect desired results. Human-computer interaction, by contrast, studies both the mechanism side and the human side, but of a narrower class of devices.

Notion of Interaction Interaction is a kind of action which occurs as two or more objects have an effect upon one another.

Example: Interaction may be the feedback during operation of a machine such as a computer or a tool. For example the interaction between a driver and the position of his or her car on the road, that the driver influences this position, by steering. A basic goal of HCI is to improve the interaction between users and computers by making computers more user-friendly and receptive to the user's needs. Specifically, HCI is concerned with: •

Methodologies and processes for designing interfaces Such as: Given a task and a class of users, design the best possible interface within given constraints, optimizing for a desired property such as learn-ability or efficiency of use.

Methods for implementing interfaces Such as: software toolkits and libraries; efficient algorithms.

Techniques for evaluating and comparing interfaces

Developing new interfaces and interaction techniques

Developing descriptive and predictive models and theories of interaction

HCI: A Three-Fold Discipline So, this discipline is concerned with three phases of interactive computing systems for human use viz. •




Productivity and HCI Productivity can be increased in two basic ways: automation and job enrichment

Discussion: Discuss how automation and job enrichment (though opposite issues) can result in better productivity. About the same discussion is valid when considering whether automation increases or decreases unemployment.

Resource Deployment Tangible Benefits Staff savings, cost savings Cost Reduction More work done more messages transmitted Improved productivity Improved information decision support Improved support New forms of integration new forms of business Organizational enhancement Work Enhancing Intangible Benefits IT benefits in an office (Eason)


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