Here are three common mistakes I find ITGS students make in exams. These may seem like minor points but they cost students marks.
Memory or storage?
The term ‘memory’ refers to primary storage (RAM or ROM), not secondary storage devices such as hard disks or CD-ROMs. Therefore it is correct to say “Video editing software requires a lot of memory“, but it is incorrect to say “My saved video files take up a lot of memory” or “There is not enough memory on my hard disk to install this software“.
USB stands for Universal Serial Bus. It is a type of connector (also called a port or an interface) for connecting many different devices: printers, keyboards, mice, digital cameras, flash drives, and so on. But a flash drive, the item you use to store your files is NOT a “USB”. It doesn’t matter who says this, or how many times they say it – it is wrong. You wouldn’t call your printer a “USB”, so why call your flash drive a “USB”?
Megabytes per second?
Computer storage is measured in bytes, kilobytes, megabytes, and gigabytes. But, confusingly, network speeds are measured in bits, kilobits, megabits, and gigabits. Remember that 1 byte equals 8 bits. This is an important distinction.
Unfortunately even tech support staff at some ISPs make this mistake (I was happy to be offered a “10 megabyte per second” connection – that’s 80 mbps! Unfortunately, the ISP wasn’t offering super fast Internet, just failing to train its staff properly. They should read this blog).
Imagine you have a 2 mbps (2048 kbps) Internet connection at home. To find out the speed in bytes, you need to divide that number by 8. 2048 divided by 8 is 256, so your maximum download speed will be 256 kilobytes per second. Watch out for these mismatched units if you are asked to do a network speed calculation, and try the questions below:
- Calculate the time taken to download a 3MB JPEG image on a 56kbps dial up connection.
- Calculate the time taken to download a 100MB file over a 5mbps connection.