2025 CCEA AS-Level Digital Technology 2650 模拟试题及答案详解

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.

Any two valid fact-finding techniques [1.5 marks each, max 3; award whole marks for two clearly correct techniques].

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.

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].

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.

Any two valid changeover methods [1.5 marks each, max 3].

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

Waterfall model [1]; RAD [1]; Agile [1].

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.

Any two valid elements [1.5 marks each, max 3].

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.

Full backup [1]; differential backup [1]; incremental backup [1].

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).

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].

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.

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].

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).

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].

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.

Correct description of parallel changeover [1]; correct description of direct changeover [1]; valid advantage of parallel changeover, clearly explained [2]; clear overall distinction [1].

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).

Correct description of corrective maintenance with valid example [2]; correct description of adaptive maintenance with valid example [2]; clear distinction drawn [1].

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.

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].

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).

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].

(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.

(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).

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.

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.

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.

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.

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.

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.

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.

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].

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.

Correct working shown (correct place values applied to each bit) [1]; correct partial sum shown [1]; correct final denary answer, 214 [1].

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.

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).

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).

JPEG identified with lossy correctly stated [2]; GIF identified with lossless correctly stated [2].

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).

Correct explanation of generic software with valid example [2]; correct explanation of special purpose software with valid example [2].

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.

Any two valid features of batch processing [1.5 marks each, max 3]; valid example application [1].

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.

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].

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.

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].

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.

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].

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).

Correct explanation of data with valid example [2]; correct explanation of information with valid example [2]; correct explanation of knowledge with valid example [2].

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.

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].

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.

Correct explanation of data validation [1.5]; correct explanation of data verification [1.5]; valid, clearly explained limitation of validation alone [3].

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.

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].

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).

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].

(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.

(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].

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.

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.

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.

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.

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.

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.

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.

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.