Edexcel GCSE Computer Science (1CP2) Exam Questions

Award one mark for any of the following:

• To make/keep a copy of files/data (1)
• To store the copy separately from the original, e.g. on a different device/in a different location (1)
• So that data can be restored if the original is lost/damaged/corrupted (1)

Do not accept "to save files" on its own, as saving is normal file management and does not make a separate copy.

Do not accept answers that describe a different utility, such as scanning for malware/viruses (anti-malware software).

Award up to two marks for a linked description such as:

• A storage limit/quota is set for each user account (1) so the drive is shared fairly between users (1)
• The operating system records how much space each user's files are using (1) and refuses to save more files when the limit is reached (1)
• Each user is given a fixed share/quota of the drive (1) so one user cannot use the space set aside for another (1)

Allow a limit set by an administrator or through the operating system's user management settings; an administrator is not required for credit.

Allow a warning that stops the save; do not award the development for a warning alone where the save is not stopped.

Do not accept responses about passwords/authentication, keeping files separate/folders with no storage limit, deleting old files, compressing files, or buying a larger drive.

Do not accept 'the operating system gives the user a bigger hard drive'.

Do not accept a single global limit for all users; the limit must apply to each user/user account.

Award up to two marks for a linked explanation such as:

• The operating system switches rapidly between processes (1) so each process runs for a short time slice before the next one starts (1)
• Each process is given a small amount of CPU time (1) so the CPU moves on to another process when that time is up (1)
• The operating system chooses which process to run next (1) so the CPU is shared between the programs (1)
• Processes take turns to use the CPU (1) because the CPU is so fast the user does not notice the switching (1)
• Only one process can run on the CPU at a time (1) so the operating system must swap processes in and out quickly (1)

For both marks, the expansion must follow/associate with the statement.

Allow 'time slice' / 'time quantum'.

Do not accept 'the computer has more than one CPU' / 'each program runs on its own CPU'.

Do not accept 'the CPU does two things at once' without saying processes take turns/are switched.

Indicative content

Types of backup that could be used

• A full backup copies all of the company's project files every time it is run, so the whole set of files is held together in one backup.
• A full backup takes longer to make and needs more storage space than an incremental backup.
• An incremental backup copies only the files that have changed since the previous backup, so it is quicker to run each evening.
• Restoring from incremental backups needs the last full backup plus every incremental backup made since, which takes longer and is more complex.
• A weekly full backup with nightly incremental backups can be suitable for the company when the reason is explained using the properties of the two types.

Where and how often backups should be made

• Backups should be kept on a separate device and, ideally, at a different location, so that a fire or theft in the office cannot destroy the computer and the backups together.
• Backups should be made regularly, for example every evening, so that at most one day's design work would be lost.
• Cloud storage can hold copies off-site automatically, without the owner taking a disk home.
• An external hard disk or USB flash drive can be used as the backup medium, with a copy kept away from the office.

How the backups would be used if the hard disk failed again

• If the hard disk fails again, the backup software is used to restore the latest full backup and any later incremental backups onto a replacement disk.
• The restored project files allow the company to carry on working and meet its clients' deadlines.
• The backups should be tested by restoring a file so that the company knows the backup is usable before it is needed.
• Backup software does not repair the failed hard disk itself, so a replacement disk is still needed.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 requires all three bullets to be developed and applied, including both types of backup (or a justified combination) and a restoration sequence; a response that describes only a full backup cannot reach Level 3.

An answer that explains only one type of backup with at most a brief location or frequency point and no developed restoration is Level 1 (1–2 marks). Credit one off-site point only: cloud storage, an external disk kept elsewhere and 'a different location' are the same point. Do not accept that backup software repairs a failed hard disk or recovers files that were never backed up; an answer that only makes this claim is Level 0. An unsupported weekly-full/nightly-incremental recommendation is not credited.