- Statistical Analysis
- First, endpoints have to be found, which show approximate
homogeneous measurements
- within each group of species. Afterwards, from these
endpoints the ones have to be selected,
- which allow a best classification between the species. To
select the correct statistical test for
- this kind of data, first of all it is necessary to find
out whether the data is approximately
- gaussian distributed or not. For this purpose a list was
calculated with summary statistics like
- minimum, maximum, mean, median and standard deviation with
help of a SAS (Statistical
- Analysis System) procedure. In addition, for each endpoint
data boxplots were raised,
- measurements split by species. These descriptive
statistical methods showed in the pre-
- examination that some of the data is approximately
gaussian distributed, others is not. This
- result allows the usage of Kruskal-Wallis-Test and other
suitable multiple tests for these
- independent sample surveys. To look for significant
differences between the investigated
- groups (sites split by species), for each of the 244
endpoints (measurements) the Kruskal-
- Wallis-Test was used for each of the data-sets. All these
tests in the pre-examination showed
- that within the group of Ursus
spelaeus proportions stay more or less equal, despite their
high
- variability in size. These calculations were the
preparation for the main examination, where
- the aim is to show that the data-sets within one group
(e.g.
Ursus spelaeus or Ursus
- deningeri) are
homogeneous and in some of the measurements or proportions significantly
- different between the investigated groups. Concluding, it
appeared to be necessary to choose
- statistical procedures in the main examination, which are
able to handle small sample sizes.
- The next step, based on the above described, was taken in
the main examination by Pivottables
- and diagrams, which give a first impression of the data.
One example for statistical
- approach is presented in the following (fig. 1 - fig. 4),
where two correlated measurements are
- applied to each other.