The document discusses graphical techniques for visualizing and analyzing multivariate data with more than two variables. It describes methods such as surface plots, multiple curve xy plots, contour plots, false color plots, scatter plot matrices, co-plots, stacked plots, and parallel coordinate plots. These techniques allow researchers to visualize relationships between multiple variables, compare data partitions, and gain insights from data with more than two dimensions. The document emphasizes that combining different plot types can provide complementary perspectives for understanding complex multivariate data.