Human-Computer Interaction

Outline
Introduction What is HCI?
Types of interfaces Existing technologies Advances in HCI Architecture Interaction design User Experience Tasks

Human
•a person who tries to accomplish a goal
•the end-user
•the member of an organization
Computer
runs applications (software)

Computer
runs applications (software) locally versus remotely

Interface
•A point where two objects meet
•A point where human can tell the computer what to do
•A point where the computer displays the requested information
Interaction
“dialogue” between humans and computers

What is HCI?
Human Computer Interaction
The interaction between user(s) and application(s) is achieved via an interface – user interface

•A process of information transfer
◦User to Machine
◦Machine to User
•HCI is also referred to as Man Machine Interaction.
•HCI is what the user sees and includes:
◦The physical controls
◦What the system looks like?
◦How the system accepts input from the user?
◦How the system responds to user input?
◦How the system outputs the results of processing?

Types of Interfaces
•Command Line Interface (CLI)
A CLI displays a prompt, the user types a command on the keyboard, the computer executes the command and provides textual output.
•Menu Driven Interface
The user has a list of items to choose from, and can make selections by highlighting one.
•Graphical User Interface (GUI)
Uses windows, icons, menus and pointers (WIMP) which can be manipulated by a mouse (and often to an extent by a keyboard as well).
•Natural Language Interface
Can range from simple command systems to voice activated text processing. Commands are spoken in “normal” language.

Advantages
◦ Very flexible with the use of “switches” (options)
◦Good for “expert” users - can quickly access commands
◦Uses the fewest system resources
Disadvantages
◦Requires the user to learn “complex” commands or language
◦“Hidden” features i.e. if the command is unknown we cannot make use of that feature
◦Not very good for novice users
Command Line Interface

Command Line Interface

Advantages
◦No need to learn complex commands/language
◦Easier for a novice to learn/use
◦Ideal when there are a limited number of options (efficient)
Disadvantages
◦Can
be frustrating for experienced users i.e. the
command they want to use is buried 5 levels deep.
◦User interface may be limited by screen space and number of options available.
Menu Driven Interface

Menu Driven Interface

Graphical User Interface
Advantages
◦Most users
suitable
interface
for inexperienced
or novice
◦Many generic packages for a GUI will share common features
Disadvantages
◦GUIs use more system resources than other types of interface

Graphical User Interface

Advantages
◦No training required
◦Can be quicker than keyboard entry
◦Hands-free
◦Can be used by the disabled
Disadvantages
◦Emerging technology – still contains “bugs”
◦Difficulty in dealing with homonyms
◦Difficult to recognize all the different ways of saying things (and regional dialects)
◦Artificial languages are often more precise
Natural Language Interface

Natural Language Interface

Architecture
• Architecture of any HCI systems is identified by:
Number of inputs and outputs in the system
Diversity of inputs and outputs in terms of modality
Workings of these diverse input and output for interaction purpose
• Based on different configuration and design of interface, HCI systems can be divided into:
Unimodal HCI system
Multimodal HCI system

Unimodal HCI System
An interface mainly relies on number and diversity of its inputs and outputs which are communication channels that enable users to interact with computer via this interface.
A system that is based on only one modality is called
unimodal.
Based on the nature of different modalities, they can be divided into three categories:
Audio-Based
Sensor-Based
Visual-Based

Audio Based HCI
It deals with information acquired by different audio signals.
information.
Key components:
◦Microphone
◦ASR(automated
speech recognition) and NLU(natural
language understanding) software
The main research areas of Audio based HCI are divided into:
◦Speech Recognition
◦Speaker Recognition
◦Auditory Emotion Analysis
◦Human-Made Noise/Sign Detections
◦Musical Interaction

Sensor Based HCI
It has the wide range of applications in our day-to-day life.
The common feature in every application is that at least one physical sensor is used between machine and human to provide interaction.
Some of the sensors range from being very sophisticated to primitive :
Pen-Based Interaction
Motion Tracking Sensors/Digitizers
Haptic Sensors
Pressure Sensors
Keyboard, Mouse, Joysticks

Visual Based HCI
It is also called as machine vision which is the observation of an environment using cameras.
In this, different aspects of human responses can be recognised visual signals.
Detection, identification and tracking of a real life entity and its translation into meaningful machine/computer input.
The main research areas of visual based HCI are:
◦Facial Expression Analysis
◦Body Movement tracking and Gesture recognition
◦Gaze Detection
Sixth Sense is one of the Visual based HCI technologies which is a wearable “Gesture Based” device.

Multimodal HCI System
Combination of multiple modalities, or usage of more than one independent channel signals for the interaction between a user and a machine is termed as multimodal human computer interaction system (MMHCI).
A multimodal interface acts as a facilitator of human- computer interaction via two or more modes of input.
It is easy to use by disabled, illiterate people.
A classic example of a multimodal system is the “Put That There” demonstration system.

Multimodal HCI System

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Interaction design
“Designing interactive products to support the way people communicate and interact in their everyday and working lives.”
Sharp, Rogers & Preece, 2007

User Experience Design
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Industrial
Design
Human-Computer Interaction
img: Dan Saffer

Neuroscience

User Experience UX
User experience is the totality of the effect or effects felt by a user as a result of interaction with, and the usage context of, a system, device, or product, including the influence of usability,
usefulness, interaction, interaction.
and emotional and savoring the
impact memory
during after

Usability
is the pragmatic component of user experience, including effectiveness, efficiency, productivity, ease-of-use, learnability, retainability, and the pragmatic aspects of user satisfaction.
Usefulness
Usefulness is the component of the UX to which system functionally gives the ability to use the system or product to accomplish the goals of work (or play).

Functionality
Functionality is power to do work (to play) seated in the non-user-interface computational features and capabilities.
Emotional Impact
Emotional impact is the affective component of UX that influences user feelings. Emotional impact includes such effects as pleasure, fun, joy of use, aesthetics, desirability, pleasure, novelty, originality, sensations, coolness, engagement, appeal and can involve deeper emotional factors such self-identity, a feeling of contribution to the world and pride of ownership.

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