Human Computer Interaction (HCI) Technology

Human Computer Interaction (HCI) Basics
And
Role of HCI in Pervasive Computing

What is Human Computer Interaction (HCI)?

• HCI is the study of interaction between people (users) and computers.

• Human Computer interaction (HCI) is characterized as a dialogue or interchange between the human and the computer because the output of one serves as the input for the other in an exchange of actions and intentions.

• Human Computer Interaction is concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them.

• Human Computer Interaction (HCI) is an interdisciplinary field in which computer scientists, engineers, psychologists, social scientists and design professional play important roles.

Human Computer Interaction (HCI) is an Interdisciplinary field

Human Computer Interaction (HCI)

• HCI tackles questions concerning how people interact with computers

• Are computers intuitive or complicated?

• Are computers rewarding or frustrating?

• How can computers be made accessible to everybody (e.g. different physical abilities, different languages etc.)?

• To what level can computer interaction be standardized?

• Are computers “user-friendly”?

• What does it mean to be “user-friendly”?

Human Computer Interaction has Three Componerts

• Human

• Computer

• Interaction

''The goal of HCI is to improve the interaction between users and computers by making computers more userfriendly and receptive to the user's needs.''

Model Human Processor

• Card, Moran and Newell (1983), described the Model Human Processor (MHP)

• A simplified view of the human processing involved in interacting with computer system.

Why do we need to understand Humans?

• Interacting with technology is cognitive.

• Human information processing referred to as cognition.

• Human cognition process is involved when interacting with system, like attention, perception and recognition, memory, learning, reasoning, problem solving and decision making.

• Need to take into account cognitive processes involved and cognitive limitations of users.

• Provides knowledge about what users can and cannot be expected to do.

• Identifies and explains the nature and causes of problems users encounter.

• Supply theories, modelling tools, guidance and methods that can lead to the design of better interactive products.

• Must consider what are users good and bad at?

Computer

• In fast, the most sophisticated machine are worthless unless they be used properly by men.

What is Interaction?

• communication 

• user <==> system

• Interaction refers to a dialogue generated by the command and data, input to the computer and the display, output of the computer and the sensory/perceptual input to the human and motor response output of the human.

• There are number of ways in which the user can communicate with the system, batch input, direct manipulation etc.

What is Interface?

• Interface is made up of a set of hardware devices and software tools from the computer side and a system of sensory, motor and cognitive processes from the human side. 

"Interaction takes place at the Interface,"

Donald Norman's Model

• Norman’s model concentrates on user’s view of the interface

• Seven stages

• user establishes the goal

• formulates intention

• specifies actions at interface

• executes action

• perceives system state

• interprets system state

• evaluates system state with respect to goal

Execution / Evaluation  Loop

• execution 

• formulates intention

• specifies actions at interface

• executes action 

• evaluation 

• perceives system state

• interprets system state

• evaluates system state with respect to goal

• goal 

• user establishes the goal 

• system

User interface (UI)

• User interface

• User interfaces mediate the interaction (dialog) between humans and computers.

• The User Interface today is often one of the most critical factors regarding the success or failure of a computer system

• Good UI design

• Increases efficiency

• Improves productivity

• Reduces errors

• Reduces training

• Improves acceptance

• A balance of two key features is needed for an effective user interface

• Expressive

• ability to achieve specific tasks efficiently

• Intuitive

• ease of use, degree of effort required to learn

''Today, user needs are recognized to be important in designing interactive computer systems, but as recently as 1980, they received little emphasis J. Grudin.''

Basic User Interface Styles

• Five commonly encountered user interface paradigms:

• Interface style 

• Command entry 

• Menu 

• Forms 

• WIMP 

• Natural language

• Expressive

• Intuitive

Command line interface

• Command entry

• Human user issues commands directly to the computer.

• Many different options customize commands (expressive).

• Requires user to learn large numbers of commands and options (not intuitive).

Menu Interface

• Menu interface

• commands organized into logical groups (more intuitive than command entry).

• A submenu can be used to present further related list of sub-functions or options.

• Menu structure limits range of options (less expressive than command entry).

• Restricted form of WIMP

Form Interface

• Form interface

• Presents specific questions to which a user must respond in order to perform some task.

• Intuitive, since users are led step by step through interaction.

• Not expressive, since form allows access to only a few specialized commands.

WIMP

• WIMP: stands for windows, icons, menus, pointers

• WIMP interfaces are familiar as they are the basis of most desktop-computer operating systems

Some other Interaction Styles

• Question/answer and query dialogue

• Point and click

• Direct Manipulation

• Three–dimensional interfaces

• Gesture Recognition

• Gaze Detection

• Speech and Speaker Recognition

• Pen based Interaction

• Motion Tracking sensors and Digitizers

• Taste and smell sensors

Principles of User interface design

• Simple and natural dialogue

• Speak the user’s language

• Minimize user’s memory load

• Provide feedback

• Provide clearly marked exits

• Provide shortcuts

• Deal with errors in a positive manner

• Provide help

Example: Speak the Users Language

• Terminology based on users’ language for task

• e.g. withdrawing money from a bank machine

• Use meaningful mnemonics, icons & abbreviations

• e.g File / Save

Example: Minimize user,s memory load

• Computers good at remembering, people are not!

• Promote Recognition over Recall

• Menus, icons, choice dialog boxes vs. commands, field formats

• Relies on visibility of objects to the user (but less is more!)

Example : Provide feedback

• Continuously inform the user about

• what it is doing

• how it is interpreting the user’s input

• user should always be aware of what is going on

Suggestions for Interface Designs

• HCI has traditionally been about designing efficient and effective systems.

• Well-designed interfaces can elicit good feelings in users.

• Expressive interfaces can provide comforting feedback.

• Badly designed interfaces make people angry and frustrated.

• Emotional interaction is concerned with how we feel and react when interacting with technologies.

• Emotional interaction is concerned with how interactive systems make people respond in emotional ways.

• Relaxed users will be more forgiving of shortcomings in design.

• Aesthetically pleasing and rewarding interfaces will increase positive affect. User interfaces should be designed to match the skills, experience and expectations of its anticipated users.

• System users often judge a system by its interface rather than its functionality.

• A poorly designed interface can cause a user to make terrible errors.

• Poor user interface design is the reason why so many software systems are never used.

• Designers should be aware of people’s physical and mental limitations (e.g. limited short-term memory) and should recognise that people make mistakes.

Basic Goal of HCI

Usabilty

• One of the key concepts in HCI.

• It is concerned with making systems easy to learn and use.

• A Usable system is:

• Easy to learn 

• Easy to remember how to use 

• Effective to use 

• Efficient to use 

• Safe to use 

• Enjoyable to use 

• In order to produce computer system with good usability; Developers must attempt to

• Understand

• The factors that determine how people use technology

• Develop

• Tools and techniques to enable building suitable systems 

• Achieve

• Efficient, effective, and safe interaction

• Put People 1st

• Their needs, capabilities and preferences for conducting various tasks should direct developers in the way that they design systems

• People should not change their way they use the system to fit with it, instead system should match their requirements

• The long term goal: To design systems that minimize the barrier between the human’s cognitive model of what they want to accomplish and the computer’s understanding of the user’s task.

Why is usability important?

• Poor usability results in

• anger and frustration

• decreased productivity in the workplace

• higher error rates

• physical and emotional injury

• equipment damage

• loss of customer loyalty

• costs money

Role of HCI in Pervasive Computing

• The technology should be invisible, hidden from sight. To develop information appliances that fit people's needs and lives. To do this companies must change the way they develop products.

• They need to start with an understanding of people: user needs first, technology last-- the opposite of how things are done now. 

• Now, computers become pervasive. They are embedded in everyday objects……

• Users do not care about what is inside the box, as long as the box does what they need.

Pervasive Computing

• Pervasive Computing is a post-desktop model of human-computer interaction in which information processing has been thoroughly integrated into everyday objects and activities.

• In the course of ordinary activities, someone “using” pervasive computing engages many computational devices and systems simultaneously, and may not necessarily even be aware that they are doing so… More formally, pervasive computing is defined as “machines that fit the human environment instead of forcing humans to enter theirs”.

• The latest research in HCI field is unmistakably Pervasive Computing.

• The term which often used interchangeably by ambient intelligence refers to the ultimate methods of Human Computer Interaction that is the deletion of a desktop and embedding of the computer in the environment so that it becomes invisible to humans while surrounding them everywhere hence the term ambient.

• single user ---> groups and larger organizations

• traditional desk top ---> computational power in the environment

• user search out computer ---> interface locates and serves user

What Makes Pervasive Computer Possibe

• Enabling Technologies

• Processing

• Cheaper, faster, smaller, more energy efficient

• Storage

• Big, fast, and smaller in size

• Networking

• Global, local, ad hoc, low power, high bandwidth, low latencies

• Sensors

• Types, speed, accuracy, price and robustness (strength)

• Display

• Projection, flexible materials, low power

• Actuators

• Computer controlled

“We already have a critical mass of devices and wireless networks. The next step is to make those devices aware of how humans work and to get them to adapt to their habits.” 

''Bo Begole, a ubicomp expert at Xerox PARC''

Ideal For Pervasive Computing

• Trying to visualize a new way of thinking about computers in the world, one that takes into account the natural human environment and allows the computer themselves to vanish into the background.

• Smart spaces and mobile device (interface )

• Rich Media Natural HCI (interaction)

• Pervasive software infrastructure (computing)

• Sensor network (networking)

Topics of HCI in Pervasive Computing

• Natural Interface

• Human speech, Gestures, Hand writing recognition

• Context Awareness

• Location Aware

• Computing Platform

• Automatic Capture and Access

• Live experience record