Identify one reason for using data compression.
Mark scheme
- B To reduce the time taken to transmit a file (1)
- The only correct answer is B. The correct answer is to reduce the time taken to transmit a file.
- A is not correct because compression reduces file size, which can reduce the number of packets sent
- C is not correct because lossy compression can reduce the quality of a file
- D is not correct because encryption, not compression, can make a file harder to open
Example answers and how they were marked
Full marks1/1
B To reduce the time taken to transmit a file
Why: Correct option (1).
No marks0/1
A To increase the number of packets sent
Why: Near miss: compression reduces the number of packets sent, so no mark.
No marks0/1
C To improve the quality of the file
Why: Misconception that compression improves quality; no mark.