As discussed in the previous chapter, when you undertake statistical analysis, you generally wish to generate one or more representative numbers (statistics, statistical coefficients and parameters) that tell you something about the world and specifically about your research question. The chapter case above gives an example, namely the findings of what changes a drug like Crestor can bring about in patients.
Other examples of statistical effects include:
You may wish to know the average return on one type of financial instrument versus another.
You may generate a correlation – as per Chapter 8 – between two variables.
You might assess change in a variable from month to month.
There are two crucial elements ...