In many situations we will want to compare two populations
parameters. To compare these two populations we can compare the
differences between the two sample means.
Example
Lets say we collected the abundance of grass species 1
and 2 one year after a wildfire. We have determined that the two
populations had burned under the same exact conditions at the same
time etc… Now lets propose that species number 1 will be in higher
abundance then species number 2 one year after the fire. This is our
research hypothesis. Therefore our null hypothesis will be that
there will be no difference in abundance of species 1 and 2
Once we have established our research and null hypothesis we run
a test statistic for a given level (assigned as the alpha level).
From this point, we can either reject our null hypothesis or not, and
then draw any conclusions from the test.
Often times a t-test is used to compare the difference between
two means.
Additional Information
t-tests and other statistical analysis |