These Advanced Higher Computing Science topics consistently produce the lowest scores. Prioritise these in your revision.
!
OOP — polymorphism and superclass array method access
The 2024 and 2025 course reports both flag that candidates consistently confuse inheritance with polymorphism and fail to explain why a method cannot be accessed via a superclass array element. The 2025 report explicitly advises that 'many candidates are incorrectly using the two terms interchangeably' and dedicates significant space to clarifying the distinction.
Affects: Question Paper — Section 1
!
Standard algorithms — insertion sort applied to 2D arrays and arrays of objects
The 2025 report notes that 'some candidates produced code to implement a bubble sort algorithm rather than an insertion sort', others 'incorrectly sorted the array in ascending rather than descending order', and 'a few candidates failed to use appropriate 2-D array indexing'. The 2024 report also flags that many candidates could not complete the insertion sort pseudocode.
Affects: Question Paper — Section 1, Project — Implementation stage
!
Testing types — distinguishing final testing, end-user testing, integrative testing and usability testing
All three course reports flag this as one of the most consistently poor areas. Candidates regularly describe end-user or acceptance testing when final testing is required, and very few can accurately justify final testing as distinct from usability testing. The 2023 report states only a few candidates could accurately name and justify final testing.
Affects: Question Paper — all sections, Project — Testing stage
!
SQL — subqueries with EXISTS and Advanced Higher operators (BETWEEN, HAVING, IN)
The 2024 report notes that 'many candidates did not complete the SQL query using the EXISTS operator with the subquery', and that most did not provide the HTML form action/method attributes in an integrated question. The 2025 report also notes some candidates still use National 5-level operators (>= instead of BETWEEN, LIKE instead of IN).
Affects: Question Paper — Section 2
!
Project design — omitting top-level data-flow design and Advanced Higher data structure design
The 2023 report states 'Most candidates did not provide a top-level design showing the intended data flow between sections of their solution, together with refinements of Advanced Higher algorithms.' The 2025 report repeats this: 'most candidates fail to include this evidence' for procedural projects, and notes OOP candidates often omit a hand-crafted UML class diagram in favour of a framework-generated one.
Affects: Project — Design stage
!
Project testing — test plan not comprehensive; missing normal/extreme/exceptional values for input validation
The 2023 report notes 'most candidates did not provide any details of the test data values that were needed to test the mandatory input validation' and only 'fewer still made any reference to the expected output in the form of error messages.' The 2025 report adds that some test plans covered fewer than ten tests despite having many requirements.
Affects: Project — Testing stage
!
Maintenance types — perfective maintenance identification and detailed evaluation of maintainability
The 2023 report states 'Descriptions of maintainability submitted by many candidates lacked sufficient detail at Advanced Higher level and bore more resemblance to responses at National 5 level.' The 2024 report flags that many candidates could not identify perfective maintenance with appropriate justification in the question paper.
Affects: Question Paper — all sections, Project — Evaluation stage
!
Project ongoing testing log — evidence added retrospectively and missing Advanced Higher concept coverage
The 2023 report notes 'it was clear that much of this evidence had been added retrospectively and omitted many of the important Advanced Higher concepts, integrative components and functional requirements.' The 2025 report repeats this finding, with some submissions containing no ongoing testing evidence at all.
Affects: Project — Implementation stage