Lecture 2: Human Interaction with Computers

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Questions and Answers

What is the primary function of printers in output devices?

Facilitating online communications

Displaying data on screens

Converting data into sound

Producing hard copies of processed data (correct)

Which of the following best describes the role of monitors in personal computing?

To serve as input devices for automation

To provide a primary display for various applications (correct)

To replace traditional print documentation

To enhance audio output for gaming

What distinguishes biometric input devices from traditional passwords?

They are easier to remember

They can be shared among multiple users

They are based on unique, physiological traits (correct)

They require physical interaction

Which of the following is NOT a typical example of an input device?

Speaker Signup and view all the answers

In professional settings, what is the primary benefit of using monitors at workstations?

To serve as the main display for editing and viewing documents Signup and view all the answers

What is the golden principle in Human-Computer Interaction (HCI)?

Users should come first. Signup and view all the answers

Which of the following is NOT mentioned as a factor affecting user abilities?

Personal preferences Signup and view all the answers

What is the recommended default font size for legibility in HCI?

Reasonably large and adjustable Signup and view all the answers

How many pieces of information can most individuals hold in their short term memory according to Miller's law?

7 +/- 2 Signup and view all the answers

Which of the following enhances the process of memorization according to the content?

Chunking information into meaningful groups Signup and view all the answers

What is meant by 'readability' in the context of user-friendly writing?

The complexity of the content overall Signup and view all the answers

What aspect of writing focuses on how clear text appears to the reader?

Legibility Signup and view all the answers

What cognitive limitation primarily affects how users interact with technology?

Memory capacity Signup and view all the answers

What is a primary feature of gaming keyboards?

They often include mechanical switches. Signup and view all the answers

Which type of mouse uses optical electronics to track its movement?

Optical Mouse Signup and view all the answers

What feature distinguishes a flatbed scanner from a handheld scanner?

Flatbed scanners have a glass pane for scanning. Signup and view all the answers

What is NOT a common application of embedded machines?

Computer workstation Signup and view all the answers

Which type of input device allows users to interact through a projected virtual interface?

Projection Keyboard Signup and view all the answers

What is a characteristic of wireless mice?

They operate using batteries. Signup and view all the answers

What type of keyboard appears on a device's screen as a software interface?

Virtual Keyboard Signup and view all the answers

Which statement about mechanical mice is FALSE?

They are typically wireless. Signup and view all the answers

What is one major drawback of using a handheld scanner?

The hand should be steady while scanning. Signup and view all the answers

Which characteristic is essential for a photo scanner?

High resolution and color depth Signup and view all the answers

What does computer vision aim to achieve?

To identify and understand objects in images and videos Signup and view all the answers

Natural language processing (NLP) primarily enables computers to:

Understand and communicate human language Signup and view all the answers

What role does sensor technology play in various industries?

It allows for the detection, measurement, and monitoring of phenomena Signup and view all the answers

The Internet of Things (IoT) refers to:

Physical objects embedded with sensors and software for data exchange Signup and view all the answers

What technology allows a device to interpret body movements as video game inputs?

Body gesture recognition Signup and view all the answers

Voice scanners verify a person's identity by:

Storing and comparing voiceprints stored in a database Signup and view all the answers

What is a limitation of using a voice scanner for biometric identification?

It can be misused through a tape recording. Signup and view all the answers

Which of the following accurately describes virtual reality?

A space where computer-generated environments allow interaction. Signup and view all the answers

What biological features are typically used in biometric identification?

Fingerprints, face structure, and eye cornea. Signup and view all the answers

What can face scanners do apart from identifying a person?

Differentiate between real people and images. Signup and view all the answers

Which of the following is NOT considered a type of biometric device?

Heart Rate Monitor Signup and view all the answers

Which of the following is an example of a visual output device?

Monitor Signup and view all the answers

What kind of technologies assist disabled individuals in interaction?

Sign language recognition and speech recognition. Signup and view all the answers

What is the purpose of data output devices?

To provide machine-readable output for further processing. Signup and view all the answers

Study Notes

Lecture 2: Human and Computer

Human users interact with computers.
The golden principle in Human-Computer Interaction (HCI) is that "people should come first".
Users have different abilities: culture, cognitive abilities, experience, physical (age, hand size, height, strength, disabilities).

Why Understand Humans in HCI?

Humans have limited information processing capacity.
This has implications for design.
Interacting with technology is a cognitive process.

Information Processing Model in Humans

Perceptual: handling sensory input from the outside world (input/output).
Memorization: memory, which controls actions.

The Perceptual System (Input)

Vision
Hearing
Smell
Taste
Touch

Human Vision

Central vision: focused area
Peripheral vision: surrounding area (rods are important for night/low-light vision; insensitive to color).

Peripheral Vision Example

Fixate on a central point.
Letters/symbols around the point should be equally readable.

Legibility

Clear text is required.
Legibility depends on:
- Size
- Contrast
- Typeface
- Spacing

Readability

Readability is about general content complexity.
Guidelines for readable writing:
- Keep it simple
- Keep it short

Simplicity Example

Bad example: complex sentence
Good example: short, clear sentence

Short Example

Bad example: lengthy description
Good example: Concise and to the point.

Design Choices (Sounds)

Attention: attracting attention to critical situations or process end.
Status information: continuous background sounds convey status (e.g., progress monitoring).
Confirmation: sound confirms an action (e.g., sound when a file is deleted).
Navigation: changing sounds indicate user location (like in hypertext).

Reaction

A visual signal takes 200 ms for reaction time
An auditory signal takes 150 ms for reaction time
Reaction time for a pain signal is 700 ms
Combinations of signals can increase speed of reaction
Practice improves reaction time.

Human Memory

The ability to store and retrieve information.
Mechanisms for memory function need to be studied (how does it work)
Arbitrary lists require studying and understanding of memory (how do we remember?)
Memory ability varies, so individuals also need to be studied in memory.

Memory Types

Sensory Memory
Short-Term Memory (Working Memory)
Long-Term Memory

Sensory Memory

Buffers for stimuli from the senses.
- Sparkler Trail (iconic memory)
- Stereo Sound (echoic memory)
- Hot Surfaces (haptic memory)
Properties
- Continuously overwritten (buffer)
- Information decay (~0.5 seconds)

Attention

Asking someone to repeat an unheard question
Cocktail Party Phenomenon

Short-Term Memory (Working Memory)

Digit Span: e.g., 2653976208134
Chunks Span: e.g., 265 397 620 8134
Miller's Law: The capacity of short-term memory is approximately 7 +/- 2 items.
Chunking: breaking up long strings of information into units. This makes remembering easier in short term memory.

Rehearsal

Spending more time can eliminate the recency effect in memory
Interference doesn't cause an entire loss of information

Long-Term Memory

Properties:
- Huge (or infinite) storage capacity.
- Slow access time (0.1 second).
- Slow (or no) decay of stored information.

Computer

Computers are now embedded in many devices: mobile phones, cameras, cars, washing machines, dishwashers, alarm clocks, ATMs, copy machines.
Computer systems are diverse and have input/output devices each impacting user interaction.
- Input devices: text entry, pointing
- Output devices: screen (small, large), digital paper.

Keyboard Types

Gaming keyboards: designed for gamers, offer special macro keys, backlighting, configurable keys (often with mechanical switches for responsiveness in gaming)
Virtual keyboards: software-based keyboards on screen; commonly used in smartphones and tablets.
Projection keyboards: virtual keyboards projected onto flat surface.

Mouse Types

Mechanical mouse: uses a ball and rollers to track movement (often corded, high-performance).
Optical mouse: uses optics to track movement.
Wireless mouse: uses wireless tech (IrDA, Bluetooth, Wi-Fi) for cursor control.

Five-Finger Input Devices

Touchscreens often use a five-finger input method.

Scanner Types

Flatbed scanner: uses a glass pane and moving optical array to scan documents or images.
Handheld scanner: smaller devices to scan items (often use hand-held operation to scan; barcode scanners a type).
Photo scanner: often used for photographs, needing higher resolution and color depth; some come with image editing software for restoration.

Future Input Mechanisms

Computer Vision: Enabling computers to identify and understand objects and people in images and videos.
Neural Language Processing (NLP): Applying machine learning to enable computers to understand and communicate with human language.
Sensor Control: Measuring and monitoring physical, chemical, or biological phenomena.
Internet of Things (IoT): A network of physical objects connected and exchanging data.

Computer Vision Devices

Eye Gaze/Retina or Iris Scanner: A device to observe eye movement for functions in video games and smartphones
Sign Recognition recognizes the movement of a player for functions in games or on tablets/smartphones.
Fingerprint/Finger Scanner/Reader: Identifies individual's fingerprints

Sensor

(There are several images depicting different sensor devices)

NLP (Natural Language Processing)

Voice Scanner: Voice prints are stored and used to verify identity (but not very reliable).

VR (Virtual Reality)

Virtual environments generated by computers allow user interactions with virtual objects via devices such as headsets, gloves, or headphones. It gives users an experience without having to perform the action.

Biometric Devices

Biometrics: identifies people using biological features (e.g., fingerprints, eye cornea, facial structure).
Types: face scanner, retina/iris scanner, voice scanner.

Face Scanner

Identifies people based on face measurements (e.g., distance between eyes, nose, mouth).

Input Interaction Fields

Security: Fingerprint recognition, iris recognition, face recognition.
Search: By image, by voice.
Disable people: Sign language recognition, Speech recognition, Foot mouse, Eye mouse.

Input/Output Interaction

Examples of input/output interactions (images).

Categories of Output Devices

Visual output: displays processed data as text, images, or video (e.g., monitors, projectors).
Data output: provides machine-readable output (e.g., plotters, 3D printers).
Print output: creates hard copies (e.g., printers).
Sound output: produces sound (e.g., speakers, headphones).

Applications of Monitor

Personal computing: monitors are used in everyday tasks
Workstations: monitors are primary display devices in professional settings

3D Printer

A device that produces three-dimensional objects.

Common Input Devices Examples

Keyboards, mice, touchscreens, webcams, graphic tools, scanners, microphones, game controllers. Each device has its own specific purpose and usage.

Enhancing Biometric Input Safety

Biometric devices use unique physiological tendencies (fingerprints, patterns, facial characteristics) for automatic identity confirmation. These serve as a safer alternative to conventional passwords and reduce unauthorized access.

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Description

This quiz explores key concepts from Lecture 2 on Human-Computer Interaction (HCI). It covers how human abilities and sensory processing influence technology design and user experience. Understand the perceptual system, memory, and the importance of prioritizing people in HCI.