Science, Maths & Technology

# Introducing data

Updated Monday 18th June 2007

Understanding the ebbs and flows of the coastline is not just about observation but also about analysing data. Data is one of those words we use everyday, but what does it actually mean?

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Chambers English Dictionary defines the word data as follows:

data, dātä, n.pl. facts given, from which others may be inferred:—sing. da'tum(q.v.) …. [L. data, things given, pa.p. neut. pl. of dare, to give.]

You might prefer the definition given in the Shorter Oxford English Dictionary:

data, things given or granted; something known or assumed as fact, and made the basis of reasoning or calculation.

Data are information. Data arise in many spheres of human activity and in all sorts of different contexts in the natural world about us.

Statistics may be described as:

• exploring, analysing and summarising data;
• designing or choosing appropriate ways to collect data and extract information from them; and
• communicating that information.

Statistics also involve constructing and testing models for describing chance phenomena. These models can be used as a basis for making inferences and drawing conclusions and finally, perhaps, for making decisions. The data themselves may arise in the natural course of things (for example, as meteorological records) or, commonly, they may be collected by survey or experiment.

Data are frequently expressed as nothing more than a list of numbers or a complicated table. As a result, very large data sets can be difficult to appreciate and interpret without some form of consolidation. This can, perhaps, be achieved through a series of simpler tables or an easily assimilated diagram. The same applies to smaller data sets, whose main message may become evident only after some procedure of sorting and summarising.

Before computers were widely available, it was often necessary to make quite detailed theoretical assumptions before beginning to investigate the data. But nowadays it is relatively easy to use a statistical computer package to explore data and acquire some intuitive ‘feel” for them, without making such assumptions. This is helpful in that the most important and informative place to start is the logical one, namely with the data themselves. The computer will make your task both possible and relatively quick.

However, you must take care not to be misled into thinking that computers have made statistical theory redundant: this is far from the truth. You will find the computer can only lead you to see where theory is needed to underpin a commonsense approach or, perhaps, to reach an informed decision. It cannot replace such theory and it is, of course, incapable of informed reasoning: as always, that is up to you. Even so, if you are to gain real understanding and expertise, your first steps are best directed towards learning to use your computer to explore data, and to obtain some tentative inferences from such exploration.

The technology explosion of recent years has made relatively cheap and powerful computers available to all of us. Furthermore, it has brought about an information explosion which has revolutionised our whole environment. Information pours in from the media, advertisements, government agencies and a host of other sources and, in order to survive, we must learn to make rational choices based on some kind of summary and analysis of it. We need to learn to select the relevant and discard the irrelevant, to sift out what is interesting, to have some kind of appreciation of the accuracy and reliability of both our information and our conclusions, and to produce succinct summaries which can be interpreted clearly and quickly.

## Taking it further

This extract is part of free course materials available through OpenLearn. To try the whole extract, visit how is data represented and what does it mean?