11.7 Making the Data Survey

11.7 Making the Data Survey

The components so far discussed form the basic backbone of the data survey. The survey?s purpose is a quick look at the data. While modeling is a time-consuming process and focuses on detail, the survey deliberately focuses on the broad picture. The idea is not to resolve problems discovered, but to discover in broad terms the use and limits to use of the data and to be forewarned of any possible problem areas before modeling. The survey will not, and is not intended to, discover all of the problems that may lurk in data, and does little, if anything, toward fixing them. That is for the miner. But the miner can only fix known problems, and knowing comes from looking at the survey results. Survey software automatically makes these measurements so the miner can focus on problem areas by producing a unified numerical and graphical output. Even without such a tool, many statistical and data analysis tools have functions that allow the data to be surveyed manually. In spite of the brevity of the look at surveying in this chapter, time spent?manually if necessary?surveying data will repay the miner dividends.

Briefly, the steps for surveying data are


	1.	Sampling confidence?estimate level of multivariable distribution capture. (This confidence puts all of the other measures into perspective, whatever they are. If you?re only 50% confident that the variability has been captured, it hardly matters what the other survey measurements are!)


	2.	Entropic analysis (normalized ranges)

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11.7 Making the Data Survey

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