A data set is a grouping of data on a particular topic. Many academics gather their own, especially in the sciences. On occasion, however, it is more useful to analyze the data already gathered and provide new insights into a topic.
Data sets which have been gathered and curated by someone else have a couple of advantages: they've been gone over several times and the errors are likely to be reduced, they're likely to have been gathered in a consistent and competent manner, and they're likely to be available electronically.
From Data Sets by Laura Trude, University of North Dakota Libraries
Pikes Peak Community College Libraries
Information ∞ Inquiry ∞ Learning