Inferential statistics are used to draw inferences about a
population from a sample.
Example
For instance consider an experiment where
tree growth rates were increased by 25 percent following a forest
thinning operation on 10 sites compared to tree growth rates on 10
sites which were not thinned. Inferential statistics allows us to
decide if the increased growth rates are due to chance or are real.
There are primarily two ways to use inferential statistics:
- The
first is to estimate a parameter about a population.
- The second
is to test a hypothesis.
For the example above, the hypothesis would
be forest thinning has no effect on tree growth rates. This type of
hypothesis is often called the null hypothesis, and is the first
step in conducting a hypothesis test. Another way we could use
inferential statistics is to simply predict or estimate what the
average effect of the thinning was on tree growth. |