CCEA AS-Level · thinka-original Practice Paper

2025 CCEA AS-Level Digital Technology 2650 Practice Paper with Answers

Thinka Jun 2025 CCEA AS Level-Style Mock — Digital Technology 2650

200 marks180 mins2025
An original Thinka practice paper modelled on the structure and difficulty of the Jun 2025 CCEA AS Level Digital Technology 2650 paper. Not affiliated with or reproduced from CCEA.

Section Assessment Unit AS 1: Approaches to System Development

Answer all six questions. Write in blue or black ink. Quality of written communication will be assessed in Questions 1(c), 4(c) and 6(c).
17 Question · 92 marks
Question 1 · Short definition / component identification
3 marks
State two fact-finding techniques a systems analyst could use to gather information about a current system during the analysis stage. [3]
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Worked solution

A systems analyst can use fact-finding techniques such as interviews (talking directly to system users), questionnaires (distributing written questions to a wide range of users), observation (watching how the current system is used in practice), or document sampling (examining existing forms, reports and records used by the current system).
Final answer: any two of interviews, questionnaires, observation, document sampling.

Marking scheme

Any two valid fact-finding techniques [1.5 marks each, max 3; award whole marks for two clearly correct techniques].
Question 2 · Short definition / component identification
3 marks
State the purpose of a test plan during the testing stage of systems development. [3]
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Worked solution

The purpose of a test plan is to set out, in advance, what aspects of the system are to be tested, the specific test data that will be used for each test, and the expected result for each test; this allows testing to be carried out systematically and lets the actual results be compared against the expected results to check whether the system is working correctly.
Final answer: a test plan specifies what is tested, the test data used, and the expected results, enabling systematic testing.

Marking scheme

Reference to specifying what is to be tested/test data [1]; reference to expected results [1]; reference to enabling systematic/organised testing or comparison against expectations [1].
Question 3 · Short definition / component identification
3 marks
State two of the four changeover methods that can be used when implementing a new system. [3]
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Worked solution

The four changeover methods used when implementing a new system are: parallel changeover, direct changeover, pilot changeover, and phased changeover.
Final answer: any two of parallel, direct, pilot, phased.

Marking scheme

Any two valid changeover methods [1.5 marks each, max 3].
Question 4 · Short definition / component identification
3 marks
Name the three main approaches to systems development covered in this specification. [3]
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Worked solution

The three main approaches to systems development are: the waterfall model, Rapid Application Development (RAD), and Agile.
Final answer: waterfall model, RAD, Agile.

Marking scheme

Waterfall model [1]; RAD [1]; Agile [1].
Question 5 · Short definition / component identification
3 marks
State two of the three main elements involved in organising a software project. [3]
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Worked solution

The main elements involved in organising a software project are: resources (e.g. staff, hardware, software, time), constraints (e.g. budget, deadlines, available skills), and risks (potential problems that could affect the project's success).
Final answer: any two of resources, constraints, risks.

Marking scheme

Any two valid elements [1.5 marks each, max 3].
Question 6 · Short definition / component identification
3 marks
State three types of backup method used to protect data. [3]
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Worked solution

The three types of backup method are: full backup (a complete copy of all data), differential backup (a copy of all changes made since the last full backup), and incremental backup (a copy of all changes made since the last backup of any type).
Final answer: full backup, differential backup, incremental backup.

Marking scheme

Full backup [1]; differential backup [1]; incremental backup [1].
Question 7 · Structured description & distinction
5 marks
Distinguish between a functional requirement and a non-functional requirement for a new stock control system, giving one example of each. [5]
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Worked solution

A functional requirement describes a specific task or function that the system must be able to perform — for example, a stock control system must allow staff to record when a delivery of stock is received into the warehouse. A non-functional requirement, by contrast, describes a quality, standard or constraint on how the system carries out its functions, rather than what it does — for example, the system must be able to process a stock update within 2 seconds, or the system must only be accessible to authorised staff members.
Final answer: functional requirements describe what the system must do (e.g. record stock received); non-functional requirements describe qualities/constraints on how it does this (e.g. response time, access restrictions).

Marking scheme

Correct explanation of functional requirement [1] with valid example [1]; correct explanation of non-functional requirement [1] with valid example [1]; clear overall distinction drawn between the two [1].
Question 8 · Structured description & distinction
5 marks
Distinguish between alpha testing and beta testing, explaining who typically carries out each and at what stage of development it takes place. [5]
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Worked solution

Alpha testing is carried out first, in-house, by the software company's own developers or dedicated testers, within a controlled testing environment, before the software is made available to anyone outside the company. Beta testing takes place after alpha testing and is carried out by a limited group of real end users, using the software in a real-world environment; this allows the developers to identify any further bugs or usability issues that were not found during alpha testing, based on genuine user feedback, before the software's full public release.
Final answer: alpha testing is in-house, controlled, and happens first; beta testing follows, using real end users in a real environment, before public release.

Marking scheme

Correct description of alpha testing (in-house/developers, controlled environment) [2]; correct description of beta testing (real end users, real environment) [2]; correct sequencing (alpha before beta) [1].
Question 9 · Structured description & distinction
5 marks
Distinguish between normal test data and erroneous test data, giving an example of each for a data entry field that should only accept a whole-number age between 0 and 120. [5]
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Worked solution

Normal test data is data that is valid and falls within the range or format the system is designed to accept; for the age field, an example would be 45, which the system should accept without any error message. Erroneous test data is data that is invalid — of the wrong type, format, or clearly outside any sensible range — which the system should detect and reject; for the age field, an example would be entering the text 'abc' (the wrong data type) or a negative number such as −5, both of which the system should refuse and prompt the user to re-enter.
Final answer: normal test data is valid, in-range data that should be accepted (e.g. 45); erroneous test data is invalid data that should be rejected (e.g. 'abc' or −5).

Marking scheme

Correct description of normal test data [1] with valid example [1]; correct description of erroneous test data [1] with valid example [1]; clear distinction drawn [1].
Question 10 · Structured description & distinction
5 marks
Distinguish between parallel changeover and direct changeover, and state one advantage of parallel changeover over direct changeover. [5]
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Worked solution

In a parallel changeover, the old and new systems are run alongside each other for a set period of time, with both processing the same data, before the old system is finally switched off. In a direct changeover, the old system is stopped completely and the new system is started immediately in its place, with no period of overlap between the two. One advantage of parallel changeover over direct changeover is that, if the new system develops faults or errors during this overlap period, the organisation can continue to rely on the old, proven system to keep operating, significantly reducing the risk of major disruption to the organisation's operations — a risk that is much higher with direct changeover, since there is no fallback system available.
Final answer: parallel runs old and new systems together before switching fully; direct switches immediately with no overlap; parallel's advantage is a safer fallback if the new system fails.

Marking scheme

Correct description of parallel changeover [1]; correct description of direct changeover [1]; valid advantage of parallel changeover, clearly explained [2]; clear overall distinction [1].
Question 11 · Structured description & distinction
5 marks
Distinguish between corrective maintenance and adaptive maintenance, giving an example of when each might be needed. [5]
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Worked solution

Corrective maintenance involves fixing errors or bugs that are discovered in a system after it has gone live and is in use — for example, fixing a bug that is causing a stock control system to calculate incorrect stock totals. Adaptive maintenance involves modifying a system so that it continues to work correctly following a change in its environment — for example, updating the system so it continues to function correctly after the operating system it runs on is upgraded to a new version.
Final answer: corrective maintenance fixes discovered errors (e.g. a stock-total bug); adaptive maintenance adjusts the system to a changed environment (e.g. an OS upgrade).

Marking scheme

Correct description of corrective maintenance with valid example [2]; correct description of adaptive maintenance with valid example [2]; clear distinction drawn [1].
Question 12 · Structured description & distinction
5 marks
Distinguish between the waterfall model and the Agile approach to systems development, referring to how each handles changes to requirements during development. [5]
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Worked solution

The waterfall model is a linear, sequential approach to systems development, in which each stage (such as analysis, design, implementation and testing) must be completed in full before the next stage begins; this makes it difficult and costly to accommodate changes to requirements once development is already underway, since earlier stages would need to be revisited. The Agile approach, by contrast, is an iterative approach in which the system is developed in a series of short cycles (often called sprints), with frequent review of progress and feedback from the client; this makes it much easier to change, add or refine requirements throughout the development process, as each cycle can incorporate new or updated requirements.
Final answer: waterfall is linear/sequential and struggles to accommodate later requirement changes; Agile is iterative, incorporating feedback and requirement changes throughout via short development cycles.

Marking scheme

Correct description of the waterfall model and its handling of changing requirements [2]; correct description of Agile and its handling of changing requirements [2]; clear distinction drawn [1].
Question 13 · Structured description & distinction
5 marks
Distinguish between selection and iteration as fundamental programming concepts, giving an example of each. [5]
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Worked solution

Selection is a fundamental programming concept that allows the program to choose between two or more different paths of execution, depending on whether a specified condition is true or false — a common example is an IF statement (e.g. IF stock < reorderLevel THEN print 'Reorder needed'). Iteration is a fundamental programming concept that allows a set of instructions to be repeated multiple times, either a fixed number of times using a count-controlled loop (e.g. a FOR loop that repeats 10 times), or repeatedly until, or while, a condition is met using a condition-controlled loop (e.g. a WHILE loop).
Final answer: selection chooses between paths based on a condition (e.g. IF); iteration repeats instructions, either a fixed number of times or until/while a condition holds (e.g. FOR/WHILE loops).

Marking scheme

Correct explanation of selection with valid example [2]; correct explanation of iteration (covering both count-controlled and condition-controlled) with valid example [2]; clear distinction drawn [1].
Question 14 · Diagrammatic modelling (Level 1 DFD)
14 marks
A small library wants to computerise its book-lending system. The system works as follows: a Member requests to borrow a Book; the system checks the Book's availability against the Book Catalogue data store; if the book is available, the system records the loan in the Loans data store and updates the Book Catalogue to show the book is no longer available; the system then sends a Loan Confirmation back to the Member.
(a) Identify the external entity in this scenario. [2]
(b) Identify the two data stores in this scenario. [2]
(c) Describe, in words, a level 1 data flow diagram (DFD) for this system. Your description should clearly identify: the processes involved (with suitable process names), the data flows between the external entity, the processes and the data stores, and the direction of each data flow. [10]
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Worked solution

(a) The external entity in this scenario is the Member, as they are the source/recipient of data from outside the system boundary.
(b) The two data stores are the Book Catalogue and the Loans data store.
(c) The system can be modelled with two processes. Process 1, 'Check Book Availability', receives a Loan Request data flow from the external entity Member; it reads from the Book Catalogue data store to check whether the requested book is available. If the book is available, Process 1 sends an Availability Confirmed data flow to Process 2, 'Record Loan and Update Catalogue'. Process 2 then writes a Loan Details data flow to the Loans data store, recording the new loan, and writes an Updated Availability data flow to the Book Catalogue data store, marking the book as no longer available. Finally, Process 2 sends a Loan Confirmation data flow back to the external entity Member, completing the transaction. Each data flow is shown as a labelled, directional arrow, correctly linking the external entity, the two processes, and the two data stores according to standard DFD conventions.
Final answer: (a) Member; (b) Book Catalogue and Loans; (c) two processes (Check Book Availability; Record Loan and Update Catalogue) linked by directional, labelled data flows to the Member entity and the two data stores as described above.

Marking scheme

(a) Member (or equivalent) [2]. (b) Book Catalogue [1]; Loans [1]. (c) Two clearly named, appropriate processes identified [2]; correct data flow from Member to Process 1 (loan request) [1]; correct data flow between Process 1 and Book Catalogue (availability check) [1]; correct data flow from Process 1 to Process 2 (availability confirmed) [1]; correct data flow from Process 2 to Loans data store (recording the loan) [1]; correct data flow from Process 2 to Book Catalogue (updating availability) [1]; correct data flow from Process 2 back to Member (confirmation) [1]; correct, consistent use of DFD conventions (labelled, directional flows) throughout the description [2] (max 10).
Question 15 · Extended comparative evaluation (QWC Banded)
8 marks
Evaluate the waterfall model and the Agile approach to systems development for a project to build a small mobile app for a start-up business, where the client's exact requirements are still being refined. Quality of written communication will be assessed in this question. [8]
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Worked solution

Indicative content: Agile is generally better suited to this project, since its iterative, sprint-based structure allows the client's evolving requirements to be incorporated throughout development, with frequent review and feedback ensuring the final app matches what the client actually needs by the end of the project. The waterfall model, by contrast, requires requirements to be fixed and fully agreed early in the process; given that the client's requirements are still being refined, using waterfall here risks the finished app not matching the client's real needs, and any late changes would be costly and disruptive to accommodate. However, a balanced answer should also note waterfall's strengths — such as producing clear documentation and being easier to plan, budget and schedule precisely — which can be valuable where requirements ARE fixed, even if they are less useful here. On balance, Agile is the more appropriate approach for this specific project, given the uncertainty in requirements.
Final answer: Agile is better suited to this project because its iterative structure accommodates the client's still-evolving requirements, whereas waterfall's need for fixed, early requirements poses a significant risk given the requirements are not yet settled.

Marking scheme

Band 2 (5–6 marks) / extended to Level 3 (7–8 marks) for detailed, accurate, well-justified evaluation of both approaches, specifically applied to the evolving-requirements scenario, with a clear, justified conclusion; accurate specialist terminology; high standard of SPaG.
Band 1 (3–4 marks): Description of both approaches with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Band 0 (1–2 marks): Basic description of one approach, lacking detail or application to the scenario; limited terminology; meaning not entirely clear.
(0 marks): No creditworthy content.
Question 16 · Extended comparative evaluation (QWC Banded)
8 marks
Evaluate the use of an object-oriented approach to programming compared with a traditional procedural approach, for developing a large, complex software system such as a hospital patient records system. Quality of written communication will be assessed in this question. [8]
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Worked solution

Indicative content: an object-oriented approach organises a large, complex system around objects, which bundle related data and the methods that act on that data together (encapsulation); this can improve data security/integrity by controlling how data is accessed and changed, and inheritance allows new classes to reuse and extend the functionality of existing classes, reducing code duplication and development time, and making the system easier to maintain and extend over time (for example, adding a new type of patient record class). A procedural approach, which separates data from the functions/procedures that act on it, can be simpler and more direct for small, straightforward programs, but for a large, complex system such as this, the lack of encapsulation makes it harder to control how shared data is modified from many different parts of the program, increasing the risk of errors and making the system progressively harder to maintain, test and extend as it grows in size and complexity. On balance, the object-oriented approach is generally more suitable for a large, complex system such as a hospital patient records system.
Final answer: the object-oriented approach's encapsulation and inheritance make it better suited to a large, complex system such as this, improving data security, code reuse and long-term maintainability compared with a procedural approach.

Marking scheme

Level 3 (7–8 marks): Detailed, accurate evaluation of both approaches, specifically applied to a large, complex system, with a justified conclusion; accurate specialist terminology (encapsulation, inheritance, classes/objects); high standard of SPaG.
Level 2 (4–6 marks): Description of both approaches with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one approach, lacking detail or application; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.
Question 17 · Extended comparative evaluation (QWC Banded)
9 marks
Evaluate the use of differential backup compared with incremental backup as a nightly backup policy for a company's data, considering both the process of creating the backups and the process of restoring data after a system failure. Quality of written communication will be assessed in this question. [9]
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Worked solution

Indicative content: with differential backup, each night's backup contains all changes made since the last FULL backup, so nightly backups grow progressively larger throughout the week; however, restoring data after a failure is simpler and faster, as it only requires the last full backup plus the single most recent differential backup. With incremental backup, each night's backup contains only the changes made since the last backup of ANY type, so nightly backups are smaller and quicker to create; however, restoring data is more complex and slower, as it requires the last full backup plus every incremental backup made since, applied in the correct sequence — and if any one of these incremental backups is missing or corrupted, the whole restore process may fail. Overall, differential backup offers a simpler, more reliable and faster restore process at the cost of larger, slower nightly backups, whereas incremental backup minimises nightly backup time and storage but at the cost of a slower, more complex and more fragile restore process; the better choice depends on whether the company prioritises fast, simple recovery or fast, space-efficient nightly backups.
Final answer: differential backup gives simpler, faster, more reliable restores at the cost of larger nightly backups; incremental backup gives smaller, faster nightly backups at the cost of a slower, more complex and riskier restore process — the right choice depends on the company's priorities.

Marking scheme

Level 3 (7–9 marks): Detailed, accurate evaluation of both backup methods covering both the backup process and the restore process, with a clear, justified conclusion; accurate specialist terminology; high standard of SPaG.
Level 2 (4–6 marks): Description of both methods with some evaluation of backup and/or restore process; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one method, lacking detail or balanced comparison; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.

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Section Assessment Unit AS 2: Fundamentals of Digital Technology

Answer all five questions. You are not permitted to use any calculating aid in this paper. Complete in black ink only. Quality of written communication will be assessed in Questions 1(d), 3(d), 4(d) and 5(e).
19 Question · 108 marks
Question 1 · Binary conversion & capacity calculation
3 marks
Convert the denary number 173 to its 8-bit binary equivalent. Show your working. [3]
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Worked solution

173 = 128 + 32 + 8 + 4 + 1 = 173. Placing 1s in the 128, 32, 8, 4 and 1 columns (and 0s elsewhere) of an 8-bit binary number (128, 64, 32, 16, 8, 4, 2, 1): 1 0 1 0 1 1 0 1.
Checking: 128+0+32+0+8+4+0+1 = 173. Correct.
Final answer: 10101101.

Marking scheme

Correct working shown (e.g. correct place-value breakdown) [1]; correct binary digits in the correct positions [1]; correct final 8-bit answer, 10101101 [1].
Question 2 · Binary conversion & capacity calculation
3 marks
Convert the 8-bit binary number 11010110 to denary. Show your working. [3]
Show answer & marking scheme

Worked solution

Using place values 128, 64, 32, 16, 8, 4, 2, 1 for the bits 1 1 0 1 0 1 1 0: 128 + 64 + 0 + 16 + 0 + 4 + 2 + 0 = 214.
Final answer: 214.

Marking scheme

Correct working shown (correct place values applied to each bit) [1]; correct partial sum shown [1]; correct final denary answer, 214 [1].
Question 3 · Binary conversion & capacity calculation
3 marks
A photograph is stored using 24 bits per pixel and has a resolution of 800 × 600 pixels. Calculate the file size of the uncompressed image in bytes. Show your working. [3]
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Worked solution

Number of pixels = 800 × 600 = 480,000 pixels.
Number of bits = 480,000 × 24 = 11,520,000 bits.
Number of bytes = 11,520,000 ÷ 8 = 1,440,000 bytes.
Final answer: 1,440,000 bytes.

Marking scheme

Correct number of pixels calculated (480,000) [1]; correct number of bits calculated (11,520,000) [1]; correct final answer in bytes, 1,440,000 [1] (own-figure rule applied for consistent arithmetic).
Question 4 · Short recall / feature listing
4 marks
State two common file formats used for storing image data, and state whether each format typically uses lossy or lossless compression. [4]
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Worked solution

JPEG (Joint Photographic Experts Group) is a common image file format that typically uses lossy compression, meaning some image data/quality is permanently discarded to achieve a smaller file size. GIF (Graphics Interchange Format) is a common image file format that uses lossless compression, meaning the file can be compressed and then restored to be identical to the original, with no loss of image data.
Final answer: JPEG (lossy); GIF (lossless).

Marking scheme

JPEG identified with lossy correctly stated [2]; GIF identified with lossless correctly stated [2].
Question 5 · Short recall / feature listing
4 marks
Explain the difference between generic software and special purpose software, and give one example of each. [4]
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Worked solution

Generic software is general-purpose software that can be used to carry out a wide range of different tasks and is suitable for many different types of user — for example, a word processor, which can be used for letters, reports, essays and many other documents. Special purpose software is designed to carry out one specific task or a narrow set of related tasks — for example, payroll software, which is designed specifically to calculate and manage employee wages.
Final answer: generic software is general-purpose, usable for many tasks (e.g. a word processor); special purpose software is designed for one specific task (e.g. payroll software).

Marking scheme

Correct explanation of generic software with valid example [2]; correct explanation of special purpose software with valid example [2].
Question 6 · Short recall / feature listing
4 marks
State two features of a batch processing system, and give one example of an application that commonly uses batch processing. [4]
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Worked solution

Two features of a batch processing system are: data is collected over a period of time and then processed together as a single group (a 'batch') at a set, scheduled time, rather than being processed immediately as each item arrives; and little or no user interaction is required once processing has begun, as the whole batch is processed automatically. A common application that uses batch processing is the processing of utility bills, or the calculation of employee payroll.
Final answer: data is grouped and processed together at a scheduled time, with little user interaction during processing; example — utility billing or payroll processing.

Marking scheme

Any two valid features of batch processing [1.5 marks each, max 3]; valid example application [1].
Question 7 · Short recall / feature listing
4 marks
State two features of a WIMP (windows, icons, menu, pointer) user interface, and state one advantage of a WIMP interface over a command line interface for an inexperienced user. [4]
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Worked solution

Two features of a WIMP interface are: icons, which are small graphical images representing programs, files or actions that the user can select; and a menu, which provides a list of options or commands from which the user can choose. One advantage of a WIMP interface over a command line interface for an inexperienced user is that it is easier and more intuitive to learn and use, since the user can point and click on visible options rather than needing to remember and correctly type specific text commands.
Final answer: e.g. icons and menus as features; advantage — more intuitive/easier for beginners since it avoids the need to memorise typed commands.

Marking scheme

Any two valid features of a WIMP interface (from windows, icons, menu, pointer) [1 mark each, max 2]; valid advantage over command line for an inexperienced user, clearly explained [2].
Question 8 · Technical explanation & distinction
6 marks
Describe the fetch-execute cycle, explaining the role of the processor, main memory and buses in this process. [6]
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Worked solution

The fetch-execute cycle is the basic process by which a computer's processor runs a program. First, in the fetch stage, the address of the next instruction to be run (held in a register) is sent from the processor to main memory via the address bus; the instruction stored at that address in main memory is then fetched and transferred back to the processor along the data bus. Next, in the decode stage, the processor decodes the instruction to determine what operation it represents. Finally, in the execute stage, the processor carries out (executes) the instruction, which may involve further data being transferred to or from main memory. Throughout this process, the control bus carries control signals that coordinate and synchronise the transfer of data and instructions between the processor and main memory.
Final answer: the address bus carries the address of the instruction to memory, the data bus transfers the instruction/data back to the processor, and the control bus carries the signals that coordinate fetching, decoding and executing each instruction.

Marking scheme

Correct description of the fetch stage, referencing the address bus [2]; correct description of the transfer of the instruction via the data bus [2]; correct reference to the role of the control bus in coordinating the cycle, and/or correct mention of decode/execute [2].
Question 9 · Technical explanation & distinction
6 marks
Explain the difference between cache memory and main memory, referring to their relative speed and their role in the fetch-execute cycle. [6]
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Worked solution

Cache memory is a small amount of very high-speed memory located very close to, or within, the processor itself. Because it is much faster to access than main memory, it is used to store instructions and data that have been recently or frequently used, so that if the processor needs them again, they can be retrieved much more quickly than if they had to be fetched from main memory each time — this reduces the average time taken for the fetch stage of the fetch-execute cycle. Main memory is significantly larger in capacity than cache memory but is considerably slower to access; it holds the program currently being run, along with its associated data, and is where the processor fetches instructions from when they are not already available in the (faster) cache.
Final answer: cache memory is small, very fast memory close to the processor used to speed up repeated access to instructions/data; main memory is much larger but slower, holding the running program more generally — using cache reduces the average time needed for the fetch stage.

Marking scheme

Correct description of cache memory (small, very fast, close to processor) [2]; correct description of main memory (larger, slower) [2]; correct explanation of how cache speeds up the fetch stage of the fetch-execute cycle [2].
Question 10 · Technical explanation & distinction
6 marks
Distinguish between data, information and knowledge, using an example of each drawn from a school attendance system. [6]
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Worked solution

Data consists of raw, unprocessed facts or figures that have no context or meaning on their own — for example, in a school attendance system, a bare code such as '1025' or the figure '09/07' stored in the system has no meaning by itself. Information is produced when data is processed and given context or meaning — for example, 'Student 1025 was recorded as absent on 09 July' is information, since the raw codes have been processed and combined to convey a meaningful fact. Knowledge is the understanding that a person builds up from information, combined with their experience and judgement, which they can use to make a decision — for example, a member of staff recognising, from several pieces of attendance information over time, that a student has a recurring pattern of absence every Monday, and using this understanding to decide that a welfare check should be arranged.
Final answer: data is raw, meaningless facts (e.g. a bare code); information is processed, meaningful data (e.g. a specific absence record); knowledge is understanding built from information and experience, used to make a decision (e.g. spotting a pattern and acting on it).

Marking scheme

Correct explanation of data with valid example [2]; correct explanation of information with valid example [2]; correct explanation of knowledge with valid example [2].
Question 11 · Technical explanation & distinction
6 marks
Explain how EACH of the following factors can affect the quality of information produced by a system: accuracy, and up-to-date/currency. [6]
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Worked solution

Accuracy affects the quality of information because information is only useful if it correctly reflects the true facts it is meant to represent; if the underlying data contains errors (for example, due to a mistyped figure or a faulty sensor), the resulting information will be incorrect, which can mislead the people using it and lead to poor decisions being made. Currency (being up to date) affects the quality of information because even accurate information can become misleading over time if it is not kept current; for example, a report based on stock levels from several weeks ago may no longer reflect the current situation, and decisions based on it could be inappropriate or costly.
Final answer: accuracy matters because inaccurate information misrepresents the facts and can lead to poor decisions; currency matters because even accurate information becomes misleading once it is out of date.

Marking scheme

Correct explanation of how accuracy affects information quality, with justification [3]; correct explanation of how currency/being up to date affects information quality, with justification [3].
Question 12 · Technical explanation & distinction
6 marks
Distinguish between data validation and data verification, and explain one limitation of using data validation alone to ensure data quality. [6]
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Worked solution

Data validation is an automated check carried out by the computer system as data is entered, to ensure the data is reasonable and sensible — for example, checking that a value falls within an expected range, or is of the correct data type or format. Data verification is a separate process, often carried out manually (for example through double entry, where data is entered twice and compared, or proofreading, where entered data is checked against the original source), used to ensure that the data entered into the system exactly matches its original source. One limitation of using data validation alone is that data can successfully pass a validation check and yet still be factually incorrect — for example, an age of '25' would pass a range check for a plausible human age, even if the person's real age is actually 52 and was simply mistyped; validation checks whether data is plausible, not whether it is actually true, so it cannot guarantee genuine accuracy on its own.
Final answer: validation is an automated plausibility check by the system (e.g. range/type checks); verification confirms entered data matches its original source (e.g. double entry); validation's limitation is that plausible-but-wrong data can still pass, so it does not guarantee true accuracy.

Marking scheme

Correct explanation of data validation [1.5]; correct explanation of data verification [1.5]; valid, clearly explained limitation of validation alone [3].
Question 13 · Technical explanation & distinction
7 marks
Explain the relationship between the terms bit, byte, kilobyte and megabyte, and state how many different values can be represented using 8 bits, showing how you arrived at your answer. [7]
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Worked solution

A bit (binary digit) is the smallest unit of data used in a computer system, and can hold one of two values, 0 or 1. A byte is a group of 8 bits, and is the standard unit used to represent, for example, a single character. A kilobyte is a unit made up of 1024 bytes, and a megabyte is a unit made up of 1024 kilobytes. The number of different values that can be represented using n bits is given by 2 to the power of n (2^n); with n = 8 bits, this is 2^8 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 256 different values.
Final answer: bit (1 binary digit) < byte (8 bits) < kilobyte (1024 bytes) < megabyte (1024 kilobytes); with 8 bits, 2^8 = 256 different values can be represented.

Marking scheme

Correct definition of a bit [1]; correct definition of a byte (8 bits) [1]; correct relationship for kilobyte (1024 bytes) [1]; correct relationship for megabyte (1024 kilobytes) [1]; correct formula (2^n) stated/applied [1]; correct final answer of 256 with working shown [2].
Question 14 · Technical explanation & distinction
7 marks
Distinguish between client-side processing and server-side processing when a web form is submitted, giving one example of a task suited to each. [7]
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Worked solution

Client-side processing is processing (such as running a script) that is carried out on the user's own device, within their web browser, rather than on the web server; it can provide immediate feedback without needing to contact the server, and a suitable example is checking that a required field has not been left blank as the user fills in the form, before it is submitted. Server-side processing is processing that is carried out on the web server itself, after the form has been submitted to it; it can access resources, such as databases, that are not available to the user's browser, and a suitable example is checking an entered username and password against records stored in a database on the server.
Final answer: client-side processing runs in the user's browser and gives immediate feedback (e.g. checking a field is not blank); server-side processing runs on the web server after submission and can access server resources such as a database (e.g. checking a username/password).

Marking scheme

Correct explanation of client-side processing [1.5] with valid, relevant example [2]; correct explanation of server-side processing [1.5] with valid, relevant example [2].
Question 15 · HTML coding snippet
6 marks
Write the HTML code needed to create a section of a web page containing:
(i) a paragraph containing the text 'Welcome to our school sports day.' [1]
(ii) an unordered list of three sports events: 'Sprint', 'Long Jump' and 'Relay' [2]
(iii) an image with the file name 'sports-day.jpg' and the alternative text 'Students at sports day' [2]
(iv) a hyperlink with the text 'View full results' that links to the page 'results.html' [1]
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Worked solution

(i) A paragraph is created using the opening and closing paragraph tags:

Welcome to our school sports day.


(ii) An unordered (bulleted) list is created using the opening and closing unordered-list tags, with each item wrapped in list-item tags:

  • Sprint

  • Long Jump

  • Relay


(iii) An image is inserted using the image tag, with the src attribute giving the file name and the alt attribute giving alternative text:
(iv) A hyperlink is created using an anchor tag, with the href attribute set to the target page and the visible link text placed between the opening and closing tags: View full results
Final answer: the four snippets above, combined in order, form the required section of the web page.

Marking scheme

(i) Correct opening and closing

tags with the specified text [1]. (ii) Correct opening and closing

    tags [1]; all three items correctly wrapped in
  • tags [1]. (iii) Correct tag with src="sports-day.jpg" [1] and alt="Students at sports day" [1]. (iv) Correct tag with href="results.html" and the specified link text [1].
Question 16 · Extended comparative evaluation (QWC Banded)
8 marks
Evaluate the use of magnetic, optical and flash secondary storage media for a school's need to store and back up a large amount of student coursework data. Quality of written communication will be assessed in this question. [8]
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Worked solution

Indicative content: magnetic storage (e.g. a hard disk drive) offers very large storage capacity at relatively low cost, making it well suited to storing large volumes of coursework data, but it is comparatively slower and, having moving parts, can be more vulnerable to physical damage if dropped or knocked. Optical storage (e.g. a DVD) is cheap and portable and can be useful for distributing or archiving fixed, unchanging copies of finished coursework, but individual discs have a relatively small capacity and are easily scratched or damaged, making them less suitable as a school's main working storage or backup medium for large amounts of data. Flash storage (e.g. an SSD or USB drive) is fast, durable (no moving parts) and portable, making it very suitable for actively working with coursework files and for taking backups off-site, though larger-capacity flash storage remains more expensive per gigabyte than magnetic storage. On balance, a combination is likely best: magnetic storage (or a school server built on it) for the bulk, day-to-day storage of coursework, with flash storage used for portable backups, given its durability and speed.
Final answer: magnetic storage suits bulk, low-cost storage; flash storage suits fast, durable, portable backups; optical storage is a cheap option mainly for archiving fixed copies — a combination of magnetic (main storage) and flash (backup) best meets the school's needs.

Marking scheme

Level 3 (7–8 marks): Detailed, accurate evaluation of all three storage media, each applied to the school coursework scenario, with a justified conclusion/recommendation; accurate specialist terminology; high standard of SPaG.
Level 2 (4–6 marks): Description of at least two media with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one storage medium, lacking detail or application; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.
Question 17 · Extended comparative evaluation (QWC Banded)
8 marks
Evaluate the effectiveness of using zipping (lossless compression) compared with a lossy compression format such as JPEG, for archiving a school's photographic records of sports day. Quality of written communication will be assessed in this question. [8]
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Worked solution

Indicative content: zipping is a lossless compression method, meaning that when a zipped file is decompressed, it is restored exactly to its original state with no loss of image quality or detail; however, because no data is discarded, lossless compression typically achieves a smaller reduction in file size than lossy compression, especially for complex, detailed photographic images. JPEG uses lossy compression, permanently discarding some image data (particularly detail that is less noticeable to the human eye) to achieve a much greater reduction in file size, which saves considerably more storage space when archiving a large number of photographs; however, this loss of quality is permanent, and if the images may need to be reproduced at high quality in the future (for example for printing or official records), some of the original detail will have been irretrievably lost. On balance, if storage space is the main priority and some quality loss is acceptable for casual viewing, JPEG (lossy) is more effective; but if preserving the sports day photographs in their full original quality is important, lossless (zipped) storage would be the more appropriate choice, despite requiring more storage space.
Final answer: JPEG (lossy) achieves much greater file-size savings but permanently loses some image detail; zipping (lossless) preserves full image quality but saves less space — the more effective choice depends on whether storage space or preserving original quality is the school's priority.

Marking scheme

Level 3 (7–8 marks): Detailed, accurate evaluation of both lossless (zipping) and lossy (JPEG) compression, applied to the archiving scenario, with a justified conclusion; accurate specialist terminology; high standard of SPaG.
Level 2 (4–6 marks): Description of both compression types with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one compression type, lacking detail or application; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.
Question 18 · Extended comparative evaluation (QWC Banded)
8 marks
Evaluate the use of client-side processing compared with server-side processing for validating a web form's date-of-birth field before the form is submitted. Quality of written communication will be assessed in this question. [8]
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Worked solution

Indicative content: client-side validation (for example using a script that runs in the user's browser) can check the date-of-birth field immediately, as soon as the user enters or leaves the field, without needing to contact the server; this gives the user instant feedback and reduces unnecessary load on the server, but it relies on the user's own device and browser, and can potentially be bypassed or disabled by a technically able user (for example by disabling scripting), meaning it cannot be fully trusted as the only line of defence. Server-side validation, carried out on the web server once the form has been submitted, is more secure and reliable, since it is carried out in an environment the user cannot directly control or bypass; however, it requires a round trip to the server before the user receives feedback, making it slower and adding to server load, especially if used for every small error. On balance, best practice is to use both together: client-side validation for immediate, user-friendly feedback and reduced server load, backed up by server-side validation as the authoritative, secure final check that cannot be bypassed.
Final answer: client-side validation gives fast feedback and reduces server load but can potentially be bypassed; server-side validation is more secure and reliable but slower — best practice combines both, using client-side for usability and server-side as the trusted final check.

Marking scheme

Level 3 (7–8 marks): Detailed, accurate evaluation of both client-side and server-side validation, applied to the date-of-birth scenario, with a justified conclusion (e.g. recommending both together); accurate specialist terminology; high standard of SPaG.
Level 2 (4–6 marks): Description of both types with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one type, lacking detail or application; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.
Question 19 · Extended comparative evaluation (QWC Banded)
9 marks
Evaluate the effectiveness of using double-entry verification compared with a range of data validation checks (type check, range check and presence check) when a school registration system captures a new student's date of birth and year group. Quality of written communication will be assessed in this question. [9]
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Worked solution

Indicative content: double-entry verification requires the date of birth to be entered twice, with the system comparing the two entries and flagging any mismatch; this is effective at catching transcription/typing errors (the data entered not matching the intended source), but is more time-consuming for the person entering the data, and cannot detect an error that is made identically both times (for example, if the same wrong date is mistakenly typed twice, the mismatch would not be caught). Validation checks are automated and quick: a type check would ensure the date of birth is entered in the correct date format; a range check would ensure the resulting age falls within a sensible range for a student (rejecting, for example, an implausible date suggesting an age of 200); and a presence check would ensure the field has not been left blank. However, validation checks can only catch data that is implausible or of the wrong type/format — they cannot detect data that is plausible but still factually wrong (for example, a real but incorrect date of birth that still falls within a sensible range would pass every validation check). Overall, the two approaches address different kinds of error and are most effective when used together: validation checks quickly catch clearly implausible, badly formatted or missing data, while double-entry verification helps catch genuine transcription errors that validation alone would miss, though neither approach can guarantee the data is completely correct.
Final answer: validation checks (type, range, presence) quickly catch implausible, wrongly formatted or missing data but cannot detect plausible-but-wrong entries; double-entry verification catches transcription errors but is slower and cannot catch an error repeated identically twice — using both together is the most effective approach, though neither guarantees complete accuracy.

Marking scheme

Level 3 (7–9 marks): Detailed, accurate evaluation of both double-entry verification and the named validation checks, applied to the date-of-birth/year-group scenario, with a clear, justified conclusion; accurate specialist terminology; high standard of SPaG.
Level 2 (4–6 marks): Description of verification and/or validation checks with some evaluation/application to the scenario; some specialist terminology; clear meaning.
Level 1 (1–3 marks): Basic description of one method, lacking detail or balanced comparison; limited terminology; meaning not entirely clear.
Level 0 (0 marks): No creditworthy content.

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