Summarizing_Statistical_Data

back to [[Statistics]]

:[[Statistical Regularity]] -- [[Planning Research]] -- [[Interpreting Statistical Data]] -- [[Summary Statistics]]

In general, statistical data can be described as a list of ''subjects'' or ''Units'' and the data associated with each of them. Although most research uses many data types for each Unit, we will limit ourselves to just one data item each for this simple introduction. 

We have two objectives for our summary:

#We want to choose a [[Statistic]] that shows how different ''Units'' seem similar. Statistical textbooks call the solution to this objective, a ''measure of [[Central Tendency]]''.
#We want to choose another [[Statistic]] that shows how they differ. This kind of statistic is often called a ''measure of [[Statistical Variability]]''.

When we are summarizing a quantity like length or weight or age, it is common to answer the first question with the [[Arithmetic Mean]], the '''MediaN''', or the '''MoDe'''. Sometimes, we choose specific values from the [[Cumulative Distribution Function]] called [[Quantiles]].

The most common measures of variability for [[Quantitative Data]] are the [[Variance]], its square root, the [[Standard Deviation]], the [[Statistical Range]], [[Interquartile Range]], and the [[Absolute Deviation]].

----
[[Dick Beldin]]