Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• Reduces the file size / uses less storage space (1)
• Takes less time to upload/download/send (1)
• Uses less bandwidth / reduces the amount of data transferred (1)
• The file is more likely to fit within an email attachment size limit (1)
• Reduces the amount of storage needed for backups / more files can be stored on backup media (1)

Do not award both 'reduces the file size' and 'uses less storage space' as two separate benefits.

Do not award both 'takes less time to send' and 'uses less bandwidth' as two separate benefits.

Do not accept 'it is compressed' on its own.

Do not accept 'it makes the file easier to send' unless a benefit such as a smaller file or less time is given.

Do not accept 'better quality'.

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

• The file's entry is removed from the folder/directory (1) so the file no longer appears in the list of files/is no longer listed (1)
• The (disk) space used by the file is marked as free/available/unused (1) so another file can be saved/stored in that space (1)
• The file's data/contents are not erased/removed (1) so the file may still be recovered until the space is overwritten (1)

A point stated without development, e.g. 'the file is removed from the folder', earns one mark only.

For the first mark, accept that the file's entry is removed from the folder/directory; the second mark must state that the file no longer appears/is listed.

Do not accept 'stays on disk' alone for the third point; accept 'data is not erased' or 'contents remain'.

Do not accept 'the file is wiped from the disk straight away' or 'the data is destroyed and can never be recovered'.

Do not accept 'the file is moved to the recycle bin/bin' or 'the file is deleted from the hard drive' on its own, as this does not describe what happens to the file or the disk space.

Do not accept responses about moving the file to another folder.

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

• The start and end address/size of the block allocated to each program is recorded (1) so the operating system knows which areas of main memory are in use and which are free (1)
• The record is checked before memory is allocated (1) so memory already in use is not given to another program/is not overwritten (1)
• The record is searched for a free block that is large enough (1) so a newly loaded program is placed in a suitable area of main memory (1)
• The record is updated when a program ends/closes (1) so the memory it was using is marked as free for other programs (1)

Allow the record to be called a memory map/memory table/allocation table.

A response that only says the operating system keeps a record/list of the memory each program is using, without saying what the record contains, earns 0 marks.

A response that states what the record contains, e.g. the addresses/the start and end address of each block, earns 1 mark even if it does not say how the record is used.

Do not accept responses about saving programs/files to secondary storage or about moving programs to virtual memory, as these are not uses of this record.

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

• It allows the operating system/OS to communicate with the device/printer (1) because it translates the commands into signals the device understands (1)
• It contains/sends the instructions/commands needed by a particular device (1) so the device carries out the correct actions (1)
• It controls the device/printer (1) by sending commands/signals to it (1)
• Different devices need different commands (1) so each one needs its own driver to work with the operating system (1)

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

Do not accept 'it drives/controls the device' on its own without saying how, e.g. by sending commands/signals.

Do not accept hardware/a physical device (a device driver is software).

Do not accept 'it connects the printer to the computer' or 'it installs the printer' without saying that it provides the instructions/commands for the device.

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.