Edexcel GCSE Computer Science (1CP2) Exam Questions

Award one mark for any of the following up to a maximum of two marks:

• Manages user accounts/profiles/logins (1)
• Authenticates users when they log in (through passwords/biometrics) (1)
• Controls what each user is allowed to access (access rights/permissions) (1)
• Sets which files/folders/resources a user can use (1)
• Gives different levels of access to different users (e.g. administrator/standard user) (1)

Allow 'decides which users can use the computer' for the manage user accounts/logins mark.

Allow references to access to files/folders/resources for the access rights mark, as this is part of user management, not file management.

Do not accept 'manages users' on its own.

Do not accept 'controls user access' on its own, as it is unclear whether this means logging in or access rights.

Do not accept 'manages files' or 'manages peripherals' (these are other operating system functions).

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

How files become fragmented

• A file is saved into free blocks on the disk, so as files are deleted and new ones saved, one file can end up split across blocks in different places.
• Large files are more likely to become fragmented because they may not fit into one free space.
• The more the disks are used, the more fragmented they become, so the read/write head has to move to more locations to read all the parts of a file.
• Fragmentation is the reason that files on the college's computers take a long time to open.

What defragmentation software does

• It reorganises the blocks of each file so that they are stored together (contiguously) on the disk.
• It collects the free space into one block so that new files are written in one piece and are less likely to be fragmented.
• It is a housekeeping utility that is often supplied with the operating system, and it reorganises data that is already on the disk.
• It does not change the contents of any file, it only changes where the blocks of the file are stored.

Benefits of running it

• Files and programs open faster because the read/write head makes fewer movements, so the older computers feel quicker without the college buying new hardware.
• Free space in one block means new files are written in one piece, so the improvement lasts for a while.
• Running it may mean the college can keep using the older computers for longer instead of replacing them.

Drawbacks of running it

• It can take a long time to run, so it should be scheduled for when the room is not in use, such as overnight or at weekends.
• It causes a lot of disk activity, so running it too often puts unnecessary strain on the disks.
• It does not free up any space, as no files are deleted, so the disks will still be almost full.
• It only reorganises files that are intact, so it cannot recover a corrupted file, and a backup 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 responses must cover both how files become fragmented and what defragmentation software does, with at least one benefit or drawback applied to the college's computers. An answer that only states what the software does and one benefit, with no explanation of how files became fragmented and no drawback, is Level 1 (2 marks).

Do not accept: defragmentation software compresses files, frees up storage space, deletes unused files, repairs corrupted files, or speeds up the processor or internet connection.