General Certificate of Secondary Education (GCSE) Computer Science Flashcards

24 sample cards from the Computer Science deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. Name five common data types used in programming and give an example value of each.

   Integer ($42$), real/float ($3.14$), Boolean (True/False), character ('A'), and string ("Hello").

2. What is casting in programming?

   Casting is converting data from one data type to another, e.g. converting the string "42" into the integer $42$, or an integer into a string for output.

3. What is a string, and what does string concatenation mean?

   A string is a sequence of characters. Concatenation joins two or more strings together to make one, e.g. "Hello" + "World" gives "HelloWorld".

4. What is a one-dimensional array and how does it differ from a two-dimensional array?

   A 1D array is an ordered list of items of the same data type accessed by a single index. A 2D array stores data in rows and columns (like a table/grid) and items are accessed using two indices (row and column).

5. What is a record, and how does it differ from an array?

   A record is a data structure that groups together related fields which may be of different data types (e.g. name, age, grade). An array stores multiple items that are all the same data type.

6. What is the difference between a procedure and a function (subprogram)?

   Both are named blocks of reusable code. A function returns a value to the part of the program that called it; a procedure performs a task but does not return a value.

7. Give two advantages of using subprograms (procedures/functions).

   They make code easier to read, write and maintain by breaking it into smaller parts, and they allow code to be reused without rewriting it (reducing duplication and errors).

8. What is the difference between a local variable and a global variable?

   A local variable exists only inside the subprogram where it is declared and cannot be accessed elsewhere. A global variable is declared so it can be accessed and changed throughout the whole program.

9. What is a parameter (argument) in the context of a subprogram?

   A parameter is a value passed into a subprogram when it is called, allowing the subprogram to work with different data each time it runs.

10. What does it mean to write robust code, and name two defensive design techniques.

    Robust code anticipates and handles errors and misuse without crashing. Techniques: input validation, anticipating misuse, sanitising/authentication, and clear maintainable code with comments.

11. Distinguish between validation and verification of input.

    Validation checks that input is sensible/of the correct format before it is accepted (e.g. range check). Verification checks that input matches an expected value or that data has been entered/copied correctly (e.g. double entry, confirmation).

12. Name four common validation checks.

    Range check, presence check, length check, type check, and format/lookup check.

13. What is the difference between a syntax error and a logic error?

    A syntax error breaks the rules/grammar of the programming language so the program will not run/compile. A logic error lets the program run but produces incorrect or unexpected results because the algorithm is flawed.

14. What is the difference between iterative testing and final/terminal testing?

    Iterative testing is carried out repeatedly during development as the program is built, fixing errors as you go. Final (terminal) testing is done once on the completed program to check it meets all requirements.

15. What are the three types of test data, with an example for a field accepting values 1-10?

    Normal data (valid, e.g. 5), boundary data (on the edge of valid, e.g. 1 and 10), and erroneous/invalid data (should be rejected, e.g. 0, 11 or "x").

16. What does the Computer Misuse Act 1990 make illegal?

    Unauthorised access to computer material (hacking), unauthorised access with intent to commit further offences, and unauthorised modification of computer material (e.g. spreading malware).

17. What does the Data Protection Act protect, and state two of its principles.

    It protects individuals' personal data held by organisations. Principles include: data must be used fairly and lawfully, kept secure, accurate and up to date, used only for the stated purpose, and kept no longer than necessary.

18. What does copyright legislation (e.g. the Copyright, Designs and Patents Act) protect?

    It protects the intellectual property of creators, making it illegal to copy, use or distribute someone's work (software, music, text, images) without permission.

19. What is the difference between open source and proprietary (closed source) software?

    Open source software is distributed with its source code, which users can view, modify and redistribute, often free. Proprietary software is sold under licence with the source code hidden; users cannot legally modify or share it.

20. Give two examples of how computer technology has environmental impact.

    Manufacturing and running devices consume energy and natural resources, and discarded electronics create e-waste containing toxic materials. Devices also consume large amounts of electricity (e.g. data centres).

21. What is the digital divide and why is it a cultural/ethical concern?

    The digital divide is the gap between people who have access to digital technology and the internet and those who do not. It is a concern because lack of access can disadvantage people in education, employment and access to services.

22. What is artificial intelligence (AI) in computing?

    AI is the development of computer systems able to perform tasks that normally require human intelligence, such as recognising patterns, making decisions, understanding language and learning from data.

23. What is machine learning and how does it relate to AI?

    Machine learning is a branch of AI in which systems learn and improve from data/experience rather than being explicitly programmed for every rule, finding patterns in large datasets to make predictions or decisions.

24. State two benefits and two risks of using AI and emerging technologies.

    Benefits: automation of tedious/dangerous tasks and faster, data-driven decision making. Risks: job losses through automation, biased decisions from biased training data, and privacy/ethical concerns over data use.

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