87

ECOM II

Note the Variance Inflation Factor (VIF) values. A VIF above 10 indicates appreciable

multicollinearity. In the above table it is clear that the Manure variable is highly

correlated with a combination of other variables. Manure should probably be removed

from the analysis. But first we can see if Manure is highly correlated with  any other

single environmental variable.

Click on the Scatter Plot tab. Select Manure in Plot (x Axis) and each of the other

environmental variables in turn in the y axis menu box. If you activate the box you

can use the up and down arrows to swiftly move through the variables. Make sure you

have selected Env. in the Plot radio button or you will only be offered the species!

The scatter plot of Manure against SF indicates a Pearson correlation between these

variables of 0.72. Evidently the standard farming variable and Manure are related.

This increases our suspicion that Manure or possibly SF should be removed from the

final analysis.

We will not remove any variables from the present analysis but for future reference

this is done using the Deselect Row in the Working Environmental data tab.

It is often useful to identify the top 1, 2 or 3 environmental variables for inclusion in

the final analysis. This can be done using the 

Variable Selection 

drop down menu.

The next stage is to 

interpret the results

.

Copyright 2004  PISCES Conservation Ltd