Mark Scheme: J277/02 Computational Thinking, Algorithms and Programming (Version F)

QAnswer/Indicative ContentMarks
1.1 Abstraction: Removing unnecessary details to focus on the essential features (2).
Decomposition: Breaking a complex problem down into smaller, more manageable parts (2).
4
1.2 Inputs: Current temperature, Target temperature (2).
Process: Comparing current vs target temp (1).
Output: Signal to turn heater ON/OFF (1).
4
2.1 Illustration of a pass: Correct swaps identified (3), correct final state of the pass (3). 6
2.2 Correct truth table columns for logic circuit inputs/outputs (4). Correct logic behavior (2). 6
3.1 Misuse: SQL Injection: Entering malicious SQL code into an input field (2).
Sanitization: Removing dangerous characters from inputs before processing (3).
5
3.2 Find errors early (1), save time/money (1), ensure code meets requirements (1). 3
3.3 Iterative: Done during development, testing modules in isolation (3).
Final: Done when code is complete, testing the whole system (3). Comparison point (1).
7
4.1 Identification of Sequence (2), Selection (2), Iteration (2). 6
4.2 Integer (Whole number), Real (Decimal), Boolean (True/False), String (Text). (1 mark each). 4
4.3 Record Structure: StudentRecord (1). Fields: Name:String (1), ID:Integer (1), Grade:Character (2). 5
5 Refining: Identification of 3 errors (e.g. incorrect comparison, infinite loop, missing input) (6 marks). Rewrite of algorithm correctly (9 marks). 15
6 Algorithm:
- Array initialization (2)
- Loop for 10 entries (2)
- Input validation (e.g. range check) (4)
- Accumulating total (2)
- Calculating average correctly (3)
- Correct output (2)
15