Overall Difficulty Verdict

The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment. Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level. However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem. Consequently, the series carries an overall difficulty rating of 4 stars (3.5/5).

Where the Marks Are Distributed

The major heavy-hitters in this series are Programming Concepts (26 marks) and Algorithm Design and Problem-Solving (19 marks). In Paper 1, substantial credit was allocated to Asymmetric Encryption (9 marks) and Data Storage hardware (11 marks). In Paper 2, logical correctness and modular control structures were paramount, especially in the 15-mark scenario involving parallel arrays (CompetitorName[], CompetitorScore[], and Points[]).

Examiner Pitfalls & Common Errors

  • Logic Tracing Confusion: In the grade calculation flowchart, many candidates struggled to notice the logical flaw where the check IS Score >= 40 ? occurred first. This led to incorrect tracing outputs as subsequent thresholds were bypassed.
  • Syntax in Pseudocode: Candidates frequently lost marks on the 15-mark programming question by mixing up 1D and 2D array indexing, failing to validate inputs to the exact 0 TO 100 range, or neglecting to reset maximum value trackers correctly before search loops.
  • Asymmetric Encryption Vocabulary: The cloze passage on asymmetric encryption tested precise terminology, where mixing up public and private key roles in encryption/decryption was a common mistake.

Strategic Advice for Students

To maximize scores, focus heavily on mastering nested iteration and 2D array traversing. Practise identifying and correcting logical flaws in flowcharts by dry-running sample inputs. Additionally, learn the precise step-by-step operations of error-checking protocols like checksums and virtual memory paging, as these often carry high-value, multi-mark description points.

Future Predictions

Given the heavy focus on asymmetric encryption and databases in this series, future exams are likely to pivot towards under-tested areas such as Automated Systems (Robotics & AI), specifically the role of sensors/actuators, and File Handling in pseudocode which was notably absent in Paper 2.