AQA A Level Computer Science (7517) Past Papers 2026

On-screen examination (Skeleton Program)

Duration: 2h 30m

Written examination (Theory)

Duration: 2h 30m

NEA (Non-Exam Assessment) Project

Duration: Coursework (no time limit in exam)

Circular queues — precise pointer-based operations and empty/full checks

7517 examiners reported that question part 2.1 was not well answered, with many students describing a linear queue instead of a circular queue or failing to include the check for an empty queue before attempting deletion. Common errors included removing from the rear and describing all items moving 'up one'.

Paper 1

Regular expressions — syntax and alternation operator

7517 examiners noted that not many students were able to write an accurate regular expression, with most not using the correct symbol for alternation (|). This question is asked in the context of the skeleton program and requires confident use of regex metacharacters.

Paper 1

Floating-point representation — normalisation purpose and conversion errors

7517 examiners reported that question part 5.2 (2022) was not answered well, with many students giving vague responses such as 'increased accuracy'. In both 2022 and 2023, a common error was representing -23.25 by concatenating the representation of -23 and +0.25, which gives -22.75.

Paper 2

Start and stop bits — role in clock synchronisation

7517 examiners found that the standard response that the start bit 'identified the start of a data transmission' was not markworthy and that question parts 2.4 and 2.5 on start and stop bits 'are not well understood'. The synchronisation role of the start bit and the line-idle role of the stop bit were the expected answers.

Paper 2

Boolean algebra — operator precedence and correct application of De Morgan's law

7517 examiners reported in both 2022 and 2023 that only approximately a quarter of students achieved full marks for Boolean simplification. Recurring errors include simplifying B̄ + B to 1 prematurely when AND has higher precedence, and applying De Morgan's law across mixed AND/OR operators.

Paper 2

Transport layer and networking protocols — precise role of each OSI/TCP-IP layer

7517 examiners noted in 2023 that most students achieved only one of three marks for the transport layer, with the most common mistake being to describe the role of the network layer instead of the transport layer. Port numbers and end-to-end connection establishment were the discriminating mark points.

Paper 2

OOP concepts — protected specifier and method overriding linked to inheritance

7517 examiners reported that a significant number of students described the private specifier instead of the protected specifier. Answers for the overriding question often lacked precision — to gain the mark, answers needed to make clear the link to inheritance.

Paper 1

Functional programming — higher-order functions, recursion traces, and distributed computing properties

7517 examiners found in 2022 that fewer students could correctly apply recursive functions fw and fx in the trace table, with approximately only a quarter achieving all four marks. In 2023, features of functional programming suited to distributed code were not well known — single-word answers such as 'immutable' without explanation were not credited.

Paper 2