A-level
COMPUTER SCIENCE
7517/2
Paper 2
Mark scheme
June 2025
Version: 1.0 Final
for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
256A7517/2/MS
Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant
questions, by a panel of subject teachers. This mark scheme includes any amendments made at the
standardisation events which all associates participate in and is the scheme which was used by them in
this examination. The standardisation process ensures that the mark scheme covers the students’
responses to questions and that every associate understands and applies it in the same correct way.
As preparation for standardisation each associate analyses a number of students’ scripts. Alternative
answers not already covered by the mark scheme are discussed and legislated for. If, after the
standardisation process, associates encounter unusual answers which have not been raised they are
required to refer these to the Lead Examiner.
It must be stressed that a mark scheme is a working document, in many cases further developed and
expanded on the basis of students’ reactions to a particular paper. Assumptions about future mark
schemes on the basis of one year’s document should be avoided; whilst the guiding principles of
assessment remain constant, details will change, depending on the content of a particular examination
paper.
No student should be disadvantaged on the basis of their gender identity and/or how they refer to the
gender identity of others in their exam responses.
A consistent use of ‘they/them’ as a singular and pronouns beyond ‘she/her’ or ‘he/him’ will be credited in
exam responses in line with existing mark scheme criteria.
Further copies of this mark scheme are available from aqa.org.uk
Copyright information
2 for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own
internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party
even for internal use within the centre.
Copyright © 2025 AQA and its licensors. All rights reserved.
Level of response marking instructions
Level of response mark schemes are broken down into levels, each of which has a descriptor. The
descriptor for the level shows the average performance for the level. There are marks in each level.
Before you apply the mark scheme to a student’s answer read through the answer and annotate it (as
instructed) to show the qualities that are being looked for. You can then apply the mark scheme.
Step 1 Determine a level
Start at the lowest level of the mark scheme and use it as a ladder to see whether the answer meets the
descriptor for that level. The descriptor for the level indicates the different qualities that might be seen in
the student’s answer for that level. If it meets the lowest level then go to the next one and decide if it
meets this level, and so on, until you have a match between the level descriptor and the answer. With
practice and familiarity you will find that for better answers you will be able to quickly skip through the
lower levels of the mark scheme.
When assigning a level you should look at the overall quality of the answer and not look to pick holes in
small and specific parts of the answer where the student has not performed quite as well as the rest. If
the answer covers different aspects of different levels of the mark scheme you should use a best fit
approach for defining the level and then use the variability of the response to help decide the mark within
the level, ie if the response is predominantly level 3 with a small amount of level 4 material it would be
placed in level 3 but be awarded a mark near the top of the level because of the level 4 content.
Step 2 Determine a mark
Once you have assigned a level you need to decide on the mark. The descriptors on how to allocate
marks can help with this. The exemplar materials used during standardisation will help. There will be an
answer in the standardising materials which will correspond with each level of the mark scheme. This
answer will have been awarded a mark by the Lead Examiner. You can compare the student’s answer
with the example to determine if it is the same standard, better or worse than the example. You can then
use this to allocate a mark for the answer based on the Lead Examiner’s mark on the example.
You may well need to read back through the answer as you apply the mark scheme to clarify points and
assure yourself that the level and the mark are appropriate.
Indicative content in the mark scheme is provided as a guide for examiners. It is not intended to be
exhaustive and you must credit other valid points. Students do not have to cover all of the points
mentioned in the Indicative content to reach the highest level of the mark scheme.
An answer which contains nothing of relevance to the question must be awarded no marks.
A-level Computer Science
Paper 2
3
for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
June 2025
To Examiners:
• When to award ‘0’ (zero) when inputting marks on CMI+
A mark of 0 should be awarded where a candidate has attempted a question but failed to
write anything creditworthy.
Insert a hyphen when a candidate has not attempted a question, so that eventually the
Lead Examiner will be able to distinguish between the two (not attempted / nothing
creditworthy) in any statistics.
• This mark scheme contains the correct responses which we believe that candidates are
most likely to give. Other valid responses are possible to some questions and should be
credited. Examiners should refer responses that are not covered by the mark scheme, but
which they deem creditworthy, to a Team Leader.
The following annotation is used in the mark scheme:
; - means a single mark
// - means alternative response
/ - means an alternative word or sub-phrase
A. - means acceptable creditworthy answer
R. - means reject answer as not creditworthy
NE. - means not enough
I. - means ignore
DPT. - in some questions a specific error made by a candidate, if repeated, could result in the
loss of more than one mark. The DPT label indicates that this mistake should only
result in a candidate losing one mark on the first occasion that the error is made.
Provided that the answer remains understandable, subsequent marks should be awarded
as if the error was not being repeated.
Examiners are required to assign each of the candidates’ responses to the most appropriate level
according to its overall quality, then allocate a single mark within the level. When deciding upon a
mark in a level, examiners should bear in mind the relative weightings of the assessment objectives.
eg
In the following question, the marks available are as follows:
Question 06.4 (max 6 marks)
AO2 (analyse) – 4 marks
AO3 (programming) – 2 marks
4 for more: tyrionpapers.com
COMPUTER SCIENCE
7517/2
Paper 2
Mark scheme
June 2025
Version: 1.0 Final
for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
256A7517/2/MS
Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant
questions, by a panel of subject teachers. This mark scheme includes any amendments made at the
standardisation events which all associates participate in and is the scheme which was used by them in
this examination. The standardisation process ensures that the mark scheme covers the students’
responses to questions and that every associate understands and applies it in the same correct way.
As preparation for standardisation each associate analyses a number of students’ scripts. Alternative
answers not already covered by the mark scheme are discussed and legislated for. If, after the
standardisation process, associates encounter unusual answers which have not been raised they are
required to refer these to the Lead Examiner.
It must be stressed that a mark scheme is a working document, in many cases further developed and
expanded on the basis of students’ reactions to a particular paper. Assumptions about future mark
schemes on the basis of one year’s document should be avoided; whilst the guiding principles of
assessment remain constant, details will change, depending on the content of a particular examination
paper.
No student should be disadvantaged on the basis of their gender identity and/or how they refer to the
gender identity of others in their exam responses.
A consistent use of ‘they/them’ as a singular and pronouns beyond ‘she/her’ or ‘he/him’ will be credited in
exam responses in line with existing mark scheme criteria.
Further copies of this mark scheme are available from aqa.org.uk
Copyright information
2 for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own
internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party
even for internal use within the centre.
Copyright © 2025 AQA and its licensors. All rights reserved.
Level of response marking instructions
Level of response mark schemes are broken down into levels, each of which has a descriptor. The
descriptor for the level shows the average performance for the level. There are marks in each level.
Before you apply the mark scheme to a student’s answer read through the answer and annotate it (as
instructed) to show the qualities that are being looked for. You can then apply the mark scheme.
Step 1 Determine a level
Start at the lowest level of the mark scheme and use it as a ladder to see whether the answer meets the
descriptor for that level. The descriptor for the level indicates the different qualities that might be seen in
the student’s answer for that level. If it meets the lowest level then go to the next one and decide if it
meets this level, and so on, until you have a match between the level descriptor and the answer. With
practice and familiarity you will find that for better answers you will be able to quickly skip through the
lower levels of the mark scheme.
When assigning a level you should look at the overall quality of the answer and not look to pick holes in
small and specific parts of the answer where the student has not performed quite as well as the rest. If
the answer covers different aspects of different levels of the mark scheme you should use a best fit
approach for defining the level and then use the variability of the response to help decide the mark within
the level, ie if the response is predominantly level 3 with a small amount of level 4 material it would be
placed in level 3 but be awarded a mark near the top of the level because of the level 4 content.
Step 2 Determine a mark
Once you have assigned a level you need to decide on the mark. The descriptors on how to allocate
marks can help with this. The exemplar materials used during standardisation will help. There will be an
answer in the standardising materials which will correspond with each level of the mark scheme. This
answer will have been awarded a mark by the Lead Examiner. You can compare the student’s answer
with the example to determine if it is the same standard, better or worse than the example. You can then
use this to allocate a mark for the answer based on the Lead Examiner’s mark on the example.
You may well need to read back through the answer as you apply the mark scheme to clarify points and
assure yourself that the level and the mark are appropriate.
Indicative content in the mark scheme is provided as a guide for examiners. It is not intended to be
exhaustive and you must credit other valid points. Students do not have to cover all of the points
mentioned in the Indicative content to reach the highest level of the mark scheme.
An answer which contains nothing of relevance to the question must be awarded no marks.
A-level Computer Science
Paper 2
3
for more: tyrionpapers.com
, MARK SCHEME – A-LEVEL COMPUTER SCIENCE – 7517/2 – JUNE 2025
June 2025
To Examiners:
• When to award ‘0’ (zero) when inputting marks on CMI+
A mark of 0 should be awarded where a candidate has attempted a question but failed to
write anything creditworthy.
Insert a hyphen when a candidate has not attempted a question, so that eventually the
Lead Examiner will be able to distinguish between the two (not attempted / nothing
creditworthy) in any statistics.
• This mark scheme contains the correct responses which we believe that candidates are
most likely to give. Other valid responses are possible to some questions and should be
credited. Examiners should refer responses that are not covered by the mark scheme, but
which they deem creditworthy, to a Team Leader.
The following annotation is used in the mark scheme:
; - means a single mark
// - means alternative response
/ - means an alternative word or sub-phrase
A. - means acceptable creditworthy answer
R. - means reject answer as not creditworthy
NE. - means not enough
I. - means ignore
DPT. - in some questions a specific error made by a candidate, if repeated, could result in the
loss of more than one mark. The DPT label indicates that this mistake should only
result in a candidate losing one mark on the first occasion that the error is made.
Provided that the answer remains understandable, subsequent marks should be awarded
as if the error was not being repeated.
Examiners are required to assign each of the candidates’ responses to the most appropriate level
according to its overall quality, then allocate a single mark within the level. When deciding upon a
mark in a level, examiners should bear in mind the relative weightings of the assessment objectives.
eg
In the following question, the marks available are as follows:
Question 06.4 (max 6 marks)
AO2 (analyse) – 4 marks
AO3 (programming) – 2 marks
4 for more: tyrionpapers.com
