A2 System Design

Question 1

Graphical User Interface

Answer 1

A GUI allows the user to interact with the system using windows, icons, menus and pointers or touch-based equivalents. Users interact via pointing devices, touchscreens, or trackpads.
Advantages: Very intuitive; Minimal training required. Visual representation makes systems accessible. Supports multitasking via windows. Discoverable – users can explore features visually.
Disadvantages: Requires more processing power and memory. Can become cluttered with too many controls. Less efficient for expert users than command-line interfaces.

Question 2

Command-Line Interface

Answer 2

A text-based interface allows users to interact with a computer by typing commands using a specific syntax into a terminal.
Advantages: Fast for expert users. Allows complex operations with short commands. Requires very little processing power. Easy to automate tasks with scripts.
Disadvantages: Steep learning curve; not suitable for novice users. Requires memorisation of commands and syntax. Errors easily occur due to typos.

Question 3

Menu Based Interface

Answer 3

Menu Based interface is where the user interacts with the system by selecting options from a structured list of choices, rather than typing commands. The system guides the user through menus and submenus, making it easy to navigate, reducing input errors, and requiring little training.
Advantages: Easy to use even for beginners. Reduces errors, users can’t type wrong commands. Fast navigation, choices are clear. Works well on touchscreens or simple devices.
Disadvantages: Limited flexibility, can only do what’s on the menu. Can be slow if many levels of menus. Not ideal for expert users who prefer shortcuts or commands.

Question 4

Voice based Interface

Answer 4

A voice-based interface lets users communicate with a system by speaking commands that are processed through speech recognition technology.
Advantages: No training required for users. Voice is hands-free making it suitable for use in a variety of environments. Faster than typing on a keyboard.
Disadvantages: Even the best speech recognition systems sometimes make errors. If there is noise or some other sound in the room, the number of errors will increase. Regional accents can affect the outcome. Requires data connection to interpret speech and return results. Only understands certain foreign languages

Question 5

Augmented Reality

Answer 5

Augmented Reality overlays digital information or virtual objects onto the real-world environment through devices such as smartphones or AR glasses.
Advantages: Enhances, rather than replaces, real-world tasks. Good for training, learning, and visualisation. Safe for hazardous tasks.
Disadvantages: Requires specialised hardware or high-spec phone. Can cause distraction or over-reliance on the overlay. Accuracy depends on sensors/cameras.

Question 6

Natural Language Interface

Answer 6

A Natural Language Interface allows users to communicate with a computer system using everyday human language either spoken or typed rather than strict commands or menus.
Advantages: Very low learning curve. Allows conversational human like interaction. Good for non-technical users. Useful for help systems and support services.
Disadvantages: Ambiguity of language can lead to incorrect interpretations. Requires complex NLP algorithms. May be slow or inaccurate with unusual phrasing. Still limited compared to human understanding.

Question 7

Design based validation

Answer 7

Design validation is the process of checking that a proposed design meets its requirements and is suitable before implementation.
1. Check correspondence with the specification. Ensure the design fully meets the requirements outlined in the specification. Detect omissions or inconsistencies early, before coding begins.
2. Confirm appropriate techniques have been used. Verify that the chosen algorithms, data structures, and modelling techniques are suitable. Ensure efficiency, reliability, and maintainability of the design.
3. Confirm that the user interface is appropriate. Ensure the UI is intuitive, accessible, and user-friendly. Check that it meets user needs and usability standards.

Question 8

Design Evaluation

Answer 8

Performance. Evaluate the performance of the solution. It should be fully optimised, using minimal memory and system resources. A successful solution must complete specific tasks within an acceptable time frame.
Usability. Evaluate how easy the solution is for the end user to use. A successful solution should provide an intuitive user interface suitable for the target user.
Robustness. Evaluate the solution using its test results. The solution should include error-trapping and validation methods so it is robust and reduces the chance of system errors or failures.
Requirements. Evaluate the solution against the original requirements. All requirements should be met for the solution to be considered successful.
Cost. Evaluate the solution against costs, including financial cost, human cost, and resource cost. A solution must not exceed any negotiated or agreed costs to be successful.