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Exploratory data analysis

Exploratory data anaysis (EDA) is that part of statistical practice concerned with reviewing, communicating and using data where there is a low level of knowledge about its cause system. It was so named by John Tukey.

Tukey held that too much emphasis in statistics was placed on evaluating and testing given hypotheses (confirmatory data analysis) and that the balance was in need of redressing in favour of using data to suggest hypotheses to test. In particular, confusion of the two types of analysis and employing them on the same set of data can lead to bias owing to the effect of testing hypotheses suggested by the data.

The objectives of EDA are to:

The principle graphical tools used in EDA are:

The principle quantitative tools are: