In many circumstances, the null hypothesis is that the data are the product of being randomly drawn from a normal distribution, what is often called a bell curve, or sometimes, a Gaussian distribution (after the great mathematician Carl Friedrich Gauss):
The null hypothesis states what we would expect purely from chance alone, in the absence of anything interesting (such as a trend) in the data. This leads us to consider the concept of the null hypothesis. For example, if we want to know whether or not a data series, such as global average temperatures, display a trend, we need to think carefully about what it means to say that a data series has a trend! To ask questions of a data set, one has to first formalize the question in a meaningful way. They require us, first of all, to introduce the concept of hypothesis testing. These sorts of questions may seem simple, but they are not.
#Basic data analysis methods how to#
Now that we have looked at the basic data, we need to talk about how to analyze the data to make inferences about what they may tell us.