When the situation is normal

A researcher is motivated to do experiments because of a desire to solve certain practical problems (or so we think). We wrote this book to show how, by appl3dng statistical techniques, the efficiency of finding solutions to experimental problems can be improved. We would hke to teach the reader to take full advantage of statistical techniques, not only for analyzing experimental results, but also — and principally — for systematically planning the experiments prior to making any measurements. 

Deservedly or not, statistics is a disciphne that enjoys little popularity in the chemical community and among scientists and engineers in general. Mention of the term immediately brings to mind overwhelming amounts of data inserted into huge tables. Therein lies, buried somewhere, the useful information we seek, and which we hope statistical methods will help us discover. 

The reverse is also true. Researchers who ignore statistical design methods do so at the peril of arriving at doubtful conclusions. Worse still, their poorly designed experiments may not lead to any conclusions at all, their only practical result being a waste of time and money. 

In this book, we present various techniques of experimental design and analysis. With a little study, any researcher can learn to apply them in his daily work. To discuss these techniques correctly, however, we will need a working knowledge of some statistical concepts, almost all ultimately based on the normal distribution. This is the rationale for the title chosen for this chapter. 

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