HCI Chapter 2-4: Computer Interaction Devices

Positioning, Pointing, and Drawing

• Handheld pointing devices: mouse, touchpad, trackballs, joysticks, touch screens, tablets, and eyegaze
• Mouse characteristics: planar movement and buttons (usually 1-3)
• Mouse located on desktop, requires physical space, no arm fatigue, and is an indirect manipulation device

The Mouse

• Relative movement is detectable, moves screen cursor, and is oriented in (x, y) plane
• Methods for detecting motion: mechanical and optical
• Mechanical method: ball on underside of mouse turns, rotating orthogonal potentiometers
• Optical method: light emitting diode on underside of mouse, detects fluctuating alterations in reflected light intensity
• Foot-operated mouse experiments exist, but are not common

Touchpad

• Small touch-sensitive tablets used mainly in laptop computers
• Acceleration settings are important: fast stroke for lots of pixels per inch moved, initial movement to the target
• Slow stroke for accurate positioning

Trackball and Thumbwheels

• Trackball: ball rotated inside static housing, indirect device, fairly accurate, separate buttons for picking
• Thumbwheels: for accurate CAD, two dials for X-Y cursor position; for fast scrolling, single dial on mouse

Joystick and Keyboard Nipple

• Joystick: indirect, pressure of stick equals velocity of movement, buttons for selection
• Keyboard nipple: miniature joystick in the middle of the keyboard for laptop computers

Touch-sensitive Screen

• Detects the presence of finger or stylus on the screen using interrupting light beams, capacitance changes, or ultrasonic reflections
• Direct pointing device, advantages: fast, no specialized pointer needed, suitable for hostile environments
• Disadvantages: finger can mark screen, imprecise, difficult to select small regions or perform accurate drawing

Stylus and Light Pen

• Stylus: small pen-like pointer to draw directly on screen, uses touch-sensitive surface or magnetic detection
• Light Pen: now rarely used, uses light from screen to detect location
• Both: direct, obvious to use, but can obscure screen

Digitizing Tablet

• Mouse-like device with cross hairs, used on special surface, very accurate, used for digitizing maps

Positioning, Pointing, and Drawing

• Handheld pointing devices: mouse, touchpad, trackballs, joysticks, touch screens, tablets, and eyegaze
• Mouse characteristics: planar movement and buttons (usually 1-3)
• Mouse located on desktop, requires physical space, no arm fatigue, and is an indirect manipulation device

The Mouse

• Relative movement is detectable, moves screen cursor, and is oriented in (x, y) plane
• Methods for detecting motion: mechanical and optical
• Mechanical method: ball on underside of mouse turns, rotating orthogonal potentiometers
• Optical method: light emitting diode on underside of mouse, detects fluctuating alterations in reflected light intensity
• Foot-operated mouse experiments exist, but are not common

Touchpad

• Small touch-sensitive tablets used mainly in laptop computers
• Acceleration settings are important: fast stroke for lots of pixels per inch moved, initial movement to the target
• Slow stroke for accurate positioning

Trackball and Thumbwheels

• Trackball: ball rotated inside static housing, indirect device, fairly accurate, separate buttons for picking
• Thumbwheels: for accurate CAD, two dials for X-Y cursor position; for fast scrolling, single dial on mouse

Joystick and Keyboard Nipple

• Joystick: indirect, pressure of stick equals velocity of movement, buttons for selection
• Keyboard nipple: miniature joystick in the middle of the keyboard for laptop computers

Touch-sensitive Screen

• Detects the presence of finger or stylus on the screen using interrupting light beams, capacitance changes, or ultrasonic reflections
• Direct pointing device, advantages: fast, no specialized pointer needed, suitable for hostile environments
• Disadvantages: finger can mark screen, imprecise, difficult to select small regions or perform accurate drawing

Stylus and Light Pen

• Stylus: small pen-like pointer to draw directly on screen, uses touch-sensitive surface or magnetic detection
• Light Pen: now rarely used, uses light from screen to detect location
• Both: direct, obvious to use, but can obscure screen

Digitizing Tablet

• Mouse-like device with cross hairs, used on special surface, very accurate, used for digitizing maps

The Computer

• A computer system consists of various elements that affect interaction, including input devices, output devices, virtual reality, physical interaction, paper, memory, and processing.

Interacting with Computers

• To understand human-computer interaction, it's essential to understand what computers can do, including their devices, paper, sensors, memory, processing, and networks.

A Typical Computer System

• A typical computer system consists of an screen, keyboard, and mouse/trackpad, with variations such as desktop, laptop, and PDA.
• The devices used dictate the styles of interaction that the system supports.

Prevalence of Computers

• Computers are ubiquitous, with many devices in our homes and pockets, including PDAs, PCs, laptops, phones, cameras, TVs, and more.

Interactivity

• Long ago, computing was based on batch processing, but now most computing is interactive, with rapid feedback and user control.
• Interactivity allows users to do rather than think.

Richer Interaction

• Modern computing involves richer interaction, with sensors and devices everywhere.

Text Entry Devices

• Text entry devices include keyboards, chord keyboards, phone pads, and handwriting/speech recognition devices.

Keyboards

• Keyboards are the most common text input device, allowing rapid entry of text by experienced users.
• Keyboards have a standardized layout, such as QWERTY, but alternative designs are available.

QWERTY Layout

• The QWERTY layout is not optimal for typing, as it was designed to prevent typewriter jamming.
• Alternative designs, such as Dvorak, offer faster typing and reduced fatigue, but are not widely adopted due to the large social base of QWERTY typists.

Alternative Keyboard Layouts

• Alternative layouts, such as alphabetic and Dvorak, offer improved typing speed and reduced fatigue.
• Special keyboards, such as those designed for single-handed use or to reduce fatigue, are also available.

Chord Keyboards

• Chord keyboards have a few keys and use combinations of keypresses to type letters.
• They are compact, easy to learn, and fast, but may cause fatigue and face social resistance.

Phone Pad and T9 Entry

• Phone pads and T9 entry use numeric keys with multiple presses to type letters.
• T9 predictive entry uses a dictionary to guess the correct word, allowing fast typing.

Handwriting Recognition

• Handwriting recognition allows text input using a pen and a digitizing tablet.
• Technical problems include capturing useful information, segmenting joined up writing, and interpreting individual letters.
• Handwriting recognition is used in PDAs and tablet computers.

The Computer

• A computer system consists of various elements that affect interaction, including input devices, output devices, virtual reality, physical interaction, paper, memory, and processing.

Interacting with Computers

• To understand human-computer interaction, it's essential to understand what computers can do, including their devices, paper, sensors, memory, processing, and networks.

A Typical Computer System

• A typical computer system consists of an screen, keyboard, and mouse/trackpad, with variations such as desktop, laptop, and PDA.
• The devices used dictate the styles of interaction that the system supports.

Prevalence of Computers

• Computers are ubiquitous, with many devices in our homes and pockets, including PDAs, PCs, laptops, phones, cameras, TVs, and more.

Interactivity

• Long ago, computing was based on batch processing, but now most computing is interactive, with rapid feedback and user control.
• Interactivity allows users to do rather than think.

Richer Interaction

• Modern computing involves richer interaction, with sensors and devices everywhere.

Text Entry Devices

• Text entry devices include keyboards, chord keyboards, phone pads, and handwriting/speech recognition devices.

Keyboards

• Keyboards are the most common text input device, allowing rapid entry of text by experienced users.
• Keyboards have a standardized layout, such as QWERTY, but alternative designs are available.

QWERTY Layout

• The QWERTY layout is not optimal for typing, as it was designed to prevent typewriter jamming.
• Alternative designs, such as Dvorak, offer faster typing and reduced fatigue, but are not widely adopted due to the large social base of QWERTY typists.

Alternative Keyboard Layouts

• Alternative layouts, such as alphabetic and Dvorak, offer improved typing speed and reduced fatigue.
• Special keyboards, such as those designed for single-handed use or to reduce fatigue, are also available.

Chord Keyboards

• Chord keyboards have a few keys and use combinations of keypresses to type letters.
• They are compact, easy to learn, and fast, but may cause fatigue and face social resistance.

Phone Pad and T9 Entry

• Phone pads and T9 entry use numeric keys with multiple presses to type letters.
• T9 predictive entry uses a dictionary to guess the correct word, allowing fast typing.

Handwriting Recognition

• Handwriting recognition allows text input using a pen and a digitizing tablet.
• Technical problems include capturing useful information, segmenting joined up writing, and interpreting individual letters.
• Handwriting recognition is used in PDAs and tablet computers.

System Behavior

• System behavior describes what a system does, without explaining how it does it.
• It includes a system sequence diagram as part of its description.

System Sequence Diagram

• A system sequence diagram is a fast and easily created artifact.
• It illustrates input and output events related to the systems under discussion.

This quiz covers human computer interaction concepts, specifically focusing on input devices such as mice, touchpads, trackballs, and others. It explores the characteristics of these devices and their uses.