Scree plots and parallel analysis were used to determine the appropriate number of factors to extract.
Most colonies are located well inland on nunataks - small outcrops of barren rock and scree surrounded by glaciers - with very little other avian and mammalian life.
Scree plots of eigenvalues indicated the emergence of two clear parental factors, consistently across settings.
A scree test was used to identify the number of factors.
Three components were produced based on eigenvalues greater than 1 and the scree plot confirmed the meaningfulness of the three components.
The scree test was used to determine the number of factors to be extracted.
Scree allowed retention of two factors, only one of which was reliable.
Using dual criteria of the scree plot and eigenvalues greater than one, analyses of the 10 attributes in question indicated a two-factor solution.