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Data and information; samples and populations

22 October, 2015 - 12:51

Though we tend to use data and information interchangeably in normal conversation, we need to think of them as different things when we are thinking about statistics. Data is the raw numbers before we do anything with them. Information is the product of arranging and summarizing those numbers. A listing of the score everyone earned on the first statistics test I gave last semester is data. If you summarize that data by computing the mean (the average score), or by producing a table that shows how many students earned A's, how many B's, etc. you have turned the data into information.

Imagine that one of Foothill Mill's high profile, but small sales, products is "Easy Bounce", a cushioned sock that helps keep basketball players from bruising their feet as they come down from jumping. John McGrath gave Ann and Kevin the task of finding new markets for Easy Bounce socks. Ann and Kevin have decided that a good extension of this market is college volleyball players. Before they start, they want to learn about what size socks college volleyball players wear. First they need to gather some data, maybe by calling some equipment managers from nearby colleges to ask how many of what size volleyball socks were used last season. Then they will want to turn that data into information by arranging and summarizing their data, possibly even comparing the sizes of volleyball socks used at nearby colleges to the sizes of socks sold to basketball players.