Overall Exam Verdict

The May/June 2026 (Series 3) examination for Cambridge International AS & A Level Computer Science (9618) presents a well-balanced yet technically rigorous assessment. Across Papers 13, 23, 33, and 43, the assessment maintains Cambridge's signature emphasis on standard algorithm design, structural tracing, and live practical coding.

Where the Marks Are Won

Across the four papers, substantial mark blocks are clustered in practical programming, abstract data structures, and database systems:

  • Further Programming & Practical (Paper 43): Accounting for 75 marks, this component requires exact syntax and program execution across 1D/2D arrays, OOP encapsulation, exception-handled file I/O, and recursive binary search tree traversals.
  • Databases (Paper 13): Normalisation to 3NF, referential integrity rationale, and SQL queries involving JOIN, GROUP BY, and aggregation yield high-yield marks.
  • Data Structures & Algorithms (Paper 23 & Paper 33): Linked list mechanics, RPN stack evaluation, A* search tracing, and two's complement floating-point operations test deep algorithmic comprehension.

Key Examiner Pitfalls

Examiners routinely penalize common structural oversights:

  • SQL Syntax: Omitting grouping attributes when using aggregate functions like COUNT(), or failing to qualify foreign key constraints in ALTER/CREATE TABLE.
  • Pseudocode Conventions: Using native language syntax (e.g., Python brackets or slicing) instead of standard Cambridge pseudocode keywords (MID, LEFT, NUM_TO_STR, DIV, MOD).
  • Assembly & Bit Manipulation: Confusing immediate addressing (#n) with direct addressing (<address>), and failing to properly differentiate logical shifts from arithmetic sign-preserving shifts.
  • Practical Screenshots (Paper 43): Failing to include required evidence screenshots with exact user inputs matching test cases.

Revision Strategy

Mastering standard ADT templates (linked lists, binary trees, stacks) in both pseudocode and your chosen high-level language (Python, Java, or VB.NET) is critical. Practice dry-run trace tables under timed conditions and review floating-point normalisation steps thoroughly.