ICS3211 - Intelligent

Interfaces IICombining design with technology for effective

human-computer interaction

Week 4Department of Intelligent Computer

Systems,University of Malta,

2016

HCI: Input Devices & AI

Week 4 overview:

• Decisions & Choices - recap;

• What’s new in IUIs? : trends and challenges;

• I/O devices: categories & properties;

• Display devices;

• Pros & Cons of different devices;

Learning OutcomesAt the end of this session you should be able to:

• List the various types of input devices;

• Critically assess input & interface needs for different audiences & contexts;

• Summarise key characteristics & properties of input devices;

• Describe input device features and how these may be helpful to users;

• Elaborate on Fitt’s Law to test the performance of input devices;

Recap• Take the Quiz on MOODLE VLE

• Approaching choices: preferential vs. non-preferential

• Focus on goals

• Habit

• Consequences & situation assessment

• Social Influence

What’s new in IUIs? : trends & challenges

• Interfaces as important components for interaction tasks;

• Sensor-based new interaction paradigms;

• Human-Centred data analysis;

• Pervasive affective computing;

• Challenges of IUIs;

• What are two features of interfaces which are likely to be helpful to a non-technically minded user?

• List how some interfaces adapt better to different users.

• Use the Google Doc: http://tinyurl.com/jl5bqre to write your answers.

Input Devices: categories & properties

• keyboard

• mouse

• microphone

• scanner

• digital camera

• the devices used for input and output determine the nature and capacity of information transferred between human and computer

• characteristics of the I/O devices influence user interface design to a large degree

• the choice of an inappropriate or inadequate design will diminish the performance of the task

• combinations of I/O devices can increase the usability of a system

Input/Output Devices• I/O devices are hardware elements

• connection between the physical human effectors (hands, vocal cords) and sensors (eyes, ears), and the input and output channels of computers

• also enable communication between users and software

• usually their properties and behavior can be adapted through software

• task demands and user preferences affect the choice of input and output devices to use

• e.g. the need for hands-free or silent operation

• special devices or setups for users with disabilities

Controls• Usually software elements shown on the display

• used to set preferences and make choices

• some familiar controls:

• menus

• radio buttons, check buttons, toggles, sliders

• some hardware controls:

• contrast, brightness, etc. on screens

• volume on speakers

• some controls are used for both input and output

• show users choices or current setting

• allow users to operate the control

• example: printer control

Input Devices• Purpose

• entering data into a computer system

• issuing instructions (commands) to a computer

• Input device

• transforms data from the user into a form that a computer system can process

• together with appropriate software (device drivers)

• need to specify the objects and actions of interaction

• what should be done

• how can it be done

• logical equivalence of input devices

• different devices can be used for the same input tasks

• examples

• mouse, trackpad, pen

• mouse, cursor keys

• keyboard, pen

• keyboard, microphone with speech recognition

Properties of Input Devices

• Property sensed

• States sensed (direct vs. indirect)

• Number of dimensions

• Device acquisition time

• Gain (C:D)

• Other metrics

Categories of Input Devices

• pointing devices

• purpose

• control the movement of the cursor on the screen

• manipulation of objects on GUIs

• examples

• light pen

• mouse

• touch screen

• trackpad

• pen and tablet

• joystick

• thumb wheel

• footmouse

• audio - voice/speech• microphone

• visual - digital input devices• scanners• digital cameras and charged-coupled devices

(CCDs)• light sensors

• screen brightness adjustment• not typically used for user interaction

• List three types of pointing devices:

• what key aspects differentiate the devices

• consider technology, methods, and usability

(use same Google Doc)

Consider Touch Screens:

Consider the example below when users need to move from the before screen to the after screen.

• What gesture would you expect users would do to transform from the before and after for the three examples?

(use same Google Doc)

• Consider Speech Recognition:

• Make a list of speech recognition devices & their key features

(use same Google Doc)

Additional I/O Devices• handwriting recognition• smart card • biometric device• gesture interfaces• haptic device• wearable computer • Google glass (speech interface)

• Name three applications for which you believe haptic input and output would greatly increase their usability

(use same Google Doc)

Selecting Input Devices• the input device should

• match physiological / psychological characteristics of users, their training, and their expertise• e.g. older adults may be hampered with arthritis, and may be unable to

type; inexperienced users may be unfamiliar with keyboards and keyboard layouts, etc.

• be appropriate for the tasks to be performed• e.g. a drawing task requires a device that allows continuous movement;

selecting an option from a list requires an input device that permits discrete movement, etc.

• be suitable for the intended work and environment• e.g. speech input may be useful when there is no keypad or keyboard, or

when the eyes and hands are busy, but is unsuitable in noisy conditions; automatic scanning is suitable if there is a large amount of data to be gathered, etc.

Tracking Devices• Tracking of alternative interaction devices or tracking

the position and gestures of the user

• Devices evaluated based on

• jitter

• update rates

• latency

• drift

• accuracy

• Mechanical Tracking

• Magnetic Tracking

• Ultrasonic Tracking

• Optical Tracking

• Inertial Tracking

• Hybrid Tracking

Evaluating Input Devices

• How does the input device perform? (at representative tasks)• Target Acquisition• Steering• Pursuit Tracking • Freehand drawing • Drawing lines• Tracing and digitising • Rapid or slow motion• Clicking, double clicking or dragging

Ergonomic Issues

• Reduce repetition

• Minimise force required to operate

• Natural and neutral postures

• Cues for use

Fitt’s Law• Applied for the comparison and optimisation

of pointing devices

• Movement time as a logarithmic function of the amplitude of the movement and the width of the error tolerance:

MT = a + b log2(A/W + 1)

• Fitt’s Index of difficulty describes moves in the task space using a single abstract metric of difficulty

ID = log2(A/W + 1)

MT = a + b ID

• The Index of Performance (IP), measured in bits/second, quantifies the bandwidth of a pointing device.

IP = MT/ID

Applications of Fitt’s Law

• Applies to rate-controlled input devices, area cursors or pointing under a microscope

• Results for:

• Tracking vs. dragging states

• Bandwidth of limb segments

• Effects of Lag

• C:D gain

• Scrolling and multi-scale navigation

Mapping Input Signals

• Transfer Functions - mathematical transformation that scales the data from an input device

• self-centering devices

• motion sensing devices

• Absolute devices

Feedback: responding to input

• Passive

• Visual, auditory & tactile;

• input/output correspondence:• perceptual structure;

• kinaesthetic correspondence;

• Active Haptic Feedback

The Future of Input

• Ubiquitous computing vision;

• Synthesise structure from low level input;

• Smart homes, smart wearables with intelligent use of sensors;

–Rick Rashid

“These devices will eventually replace paper print media. We are reaching a

point in the future where any surface can be an interactive surface.”