For centuries
prior to the advent of computerization, if you wanted to take raw
data and get statistics you needed to use mathematics and hard work.
Underlying most statistics is some form of mathematics. I discuss
this further in Chapter 11.
These days, luckily,
we usually use computer programs to do the hard number crunching for
us. Examples of such programs are SAS, SPSS, STATA, Statistica, NCSS,
Microsoft Excel, and a great many more. These programs look at your
raw data and – based on your telling them what you want –
they tell you what the estimated statistics are, from averages to
complex relational statistics.
As discussed in the
preface to the book, this book uses SAS, which is one of the world’s
most used statistics suites and is the leading player in business
analytics particularly.
It is crucial to note
that many statistics mistakes occur because people either give the
computer program bad data or the wrong instructions, or because people
do not adequately scrutinize the computer results. Please understand
that the fact that the computer has given you a statistical result
does not mean that it is the right output or in fact that the result
should be taken seriously! The computer is just a tool, and cannot
do the real work for you, like making sure your data is right, understanding
which statistical tests are appropriate, and understanding the results
and what to do about them. One of my favorite acronyms is “PICNIC,”
which stands for “Problem In Chair Not In Computer.”
So, try to be people who do not rely on the computer for more than
it can do.