Exam

Question 1

1.1. Limitations of Human Working Memory in HCI

Answer 1

Limited Capacity: Human working memory can only hold a small amount of information at a time (typically 7 ± 2 items, according to Miller’s Law). This means that users can easily be overloaded with too much information, leading to errors and frustration.
Short Duration: Information in working memory decays quickly, lasting only for a few seconds unless actively rehearsed. This means that interfaces should be designed to minimize the need for users to remember large amounts of information.
Interference: New information can interfere with the recall of previously stored information. This highlights the importance of keeping interfaces consistent and avoiding unnecessary complexity.

Question 2

1.2. Benefits and Drawbacks of VR Helmets

Answer 2

• Immersive Experience: VR helmets create a highly immersive experience, allowing users to feel like they are actually present in a virtual world.
• Realistic Interaction: They enable realistic interaction with virtual objects, providing a more intuitive and engaging experience.
• Training and Simulation: VR helmets are valuable for training and simulation applications, allowing users to practice skills in a safe and controlled environment.

Drawbacks:

• Cost: VR helmets can be expensive, limiting their accessibility to some users.
• Physical Discomfort: Long-term use can lead to discomfort, motion sickness, and eyestrain.
• Limited Mobility: VR helmets can restrict user movement, which can be a problem for some applications.

Question 3

1.3. Time-Sharing Computers

Answer 3

Time-sharing computers allow multiple users to access the same computer system simultaneously. Each user gets a small “slice” of processing time, creating the illusion that they have exclusive access to the computer.

Key features:

• Shared Resources: Multiple users share the computer’s processing power, memory, and peripherals.
• Multitasking: Multiple programs can be run concurrently, improving resource utilization.
• Interactive Use: Users interact with the system in real-time, rather than through batch processing.

Question 4

1.4. Elements of Computer Systems

Answer 4

• Hardware: The physical components of a computer system, including the central processing unit (CPU), memory (RAM), storage devices (hard drives, SSDs), input devices (keyboard, mouse), output devices (monitor, printer), and network interfaces.
• Software: The set of instructions that tell the hardware what to do, including operating systems, applications, and programming languages.
• Data: The information that is processed and stored by the computer system.
• Network: The connections that allow computers to communicate with each other, enabling access to shared resources and data.
• Users: The people who interact with the computer system.

Question 5

2.1. Process-Oriented and Structure-Oriented Design Rationale

Answer 5

2.1. Process-Oriented and Structure-Oriented Design Rationale

Process-Oriented:

• Focus: Captures the historical evolution of design decisions, documenting the reasoning behind choices made during the design process.
• Method: Relies on recording discussions, design iterations, and the rationale for specific design choices.
• Example: A detailed log of a team’s design meetings, including arguments for and against different options.

Structure-Oriented:

• Focus: Presents the final design rationale, summarizing the reasons behind the chosen design solution.
• Method: Emphasizes the conclusions and justifications for design decisions, without necessarily detailing the entire design process.
• Example: A document that explains the key design principles, trade-offs, and considerations that led to the final design.

Question 6

2.2. Essential Characteristics of Good Design

Answer 6

• Usability: The ease with which users can learn and use a system effectively. This is paramount for successful systems. Users should be able to perform tasks quickly and efficiently.
• Accessibility: The system should be usable by people with a wide range of abilities and disabilities. It’s about inclusivity and equal access.
• Aesthetics: Visually appealing designs are more engaging and enjoyable to use. This often leads to greater user satisfaction and longer use.
• Consistency: Consistent use of design elements, terminology, and interactions helps users learn and understand the system more quickly.
• Feedback: Providing clear and timely feedback to users about their actions helps them understand the system’s state and progress.
• Error Prevention: Designing systems to prevent errors or minimize their impact is crucial. This involves thoughtful design choices and appropriate safeguards.
• Flexibility: The system should be adaptable to different users’ needs and preferences. This could involve customization options or alternative interaction methods.

Question 7

3.1. Text Entry and Positioning Devices for Data Entry

Answer 7

Text Entry Devices:

• Ergonomic Keyboards: Designed with curved or split layouts to reduce strain on wrists and hands.
  
  • Strengths: More comfortable for long-term use, better for reducing repetitive strain injuries.
  • Weaknesses: Might require a learning curve for users accustomed to standard keyboards.
• Voice Recognition Software: Allows users to control their computer using voice commands.
  
  • Strengths: Great for users with limited hand mobility, can be faster than typing.
  • Weaknesses: Can be less accurate, requires a quiet environment, potential privacy concerns.
• On-Screen Keyboards: Virtual keyboards displayed on the screen.
  
  • Strengths: Easy to use, can be customized for different users and accessibility needs.
  • Weaknesses: Can be slower than physical keyboards, requires accurate pointing.
• Chord Keyboards: Small keyboards with few keys that allow users to type by pressing combinations of keys.
  
  • Strengths: Compact, can be faster for experienced users.
  • Weaknesses: Requires a steep learning curve, difficult for novices.

Positioning Devices:

• Vertical Mice: Mice designed to be used vertically, reducing strain on wrists.
  
  • Strengths: More ergonomic, can be more comfortable for long-term use.
  • Weaknesses: Might require some adjustment for users accustomed to standard mice.
• Trackballs: Stationary devices that allow users to control the cursor using a ball.
  
  • Strengths: Requires minimal movement, good for users with limited desk space.
  • Weaknesses: Can be less precise than mice, not ideal for drawing or graphics.
• Touchpads: Touch-sensitive surfaces integrated into laptops.
  
  • Strengths: Convenient, readily available on most laptops.
  • Weaknesses: Can be less accurate for precise pointing, not as ergonomic as mice or trackballs.
• Eye-Tracking Devices: Allow users to control the cursor using their eyes.
  
  • Strengths: Highly accurate, ideal for users with severe mobility impairments.
  • Weaknesses: Expensive, can be intrusive, require calibration.

Suitability for Tshepo’s Task:

For data entry into spreadsheets, Tshepo might benefit from:

• Ergonomic Keyboard: To reduce wrist strain and discomfort.
• Vertical Mouse: To improve ergonomics and wrist position.
• On-Screen Keyboard: For short bursts of data entry, as it can be easier to switch between keyboard and spreadsheet.

Evaluating Device Suitability:

• Context: The specific task (e.g., data entry vs. graphic design), environment (e.g., office vs. home), and user’s physical abilities and preferences.
• Usability: How easy the device is to learn and use, how accurate and efficient it is.
• Comfort: How comfortable the device is to use for extended periods.
• Cost: The affordability of the device.

Question 8

2.3. Advantages and Disadvantages of Online Documentation

Answer 8

Advantages:

• Accessibility: Easily accessible from any computer with internet access.
• Up-to-Date: Can be updated quickly and easily, ensuring users have the latest information.
• Searchable: Online documentation can be easily searched for specific information, making it more efficient to find the help users need.
• Multimedia: Allows for the inclusion of multimedia elements such as videos, images, and audio, making information more engaging and understandable.

Disadvantages:

• Technical Issues: Requires internet access and a reliable web browser.
• Accessibility for All: Some users might not have access to computers or the internet.
• Limited Print Functionality: Printing online documentation can be cumbersome and might not always result in a well-formatted print copy.

Overcoming Disadvantages:

• Offline Access: Provide options for downloading or accessing documentation offline.
• Alternative Formats: Offer documentation in accessible formats like audio or large print.
• Print Friendly Versions: Provide a print-friendly version that formats correctly when printed.

Question 9

3.2. HCI Considerations for a Healthcare Mobile Application

Answer 9

• User Needs:
  
  • Target Audience: Identify the specific healthcare professionals who will be using the app (doctors, nurses, technicians, etc.).
  • Tasks: Understand the tasks they will perform using the app (e.g., accessing patient records, ordering medication, charting, communicating with colleagues).
  • Information Requirements: Determine what information healthcare professionals need to access and how they need to interact with it.
• Usability:
  
  • Intuitive Interface: The app should be easy to navigate and understand, even under time pressure.
  • Clear and Concise Information: Display information clearly and concisely, using appropriate formatting, icons, and color.
  • Touch-Friendly Design: Optimize the interface for touch input, ensuring buttons are large enough and easy to tap.
• Security and Privacy:
  
  • Data Encryption: Protect sensitive patient information with strong encryption methods.
  • Authentication and Authorization: Implement secure login processes and restrict access to authorized personnel.
• Context of Use:
  
  • Mobile Environment: Consider factors like lighting conditions, noise levels, and potential distractions in a hospital setting.
  • Work Flow: Design the app to integrate seamlessly with existing workflows and minimize disruptions.
• Accessibility:
  
  • Visual Impairments: Use sufficient contrast, alternative text descriptions (alt text), and screen reader compatibility.
  • Motor Impairments: Provide voice control options and alternative input methods.
• Feedback and Error Prevention:
  
  • Real-time Updates: Keep users informed about the progress of tasks and system status.
  • Error Messages: Provide clear and concise error messages that help users understand and resolve problems.
• Testing and Iteration:
  
  • User Testing: Involve target users in testing the app to gather feedback and identify usability issues.
  • Iterative Design: Use feedback to refine the design and improve the user experience.