Very long article posted by Sebastian Raschka in 2014. Here we only provide the table of content, and a chart showing the results of PCA applied to a wine dataset. A link to the full version is provided below. The article is rather technical and uses Python, including the scikit-learn, numpy. pandas and matplotlib libraries. Interesting for anyone working with scores and looking for normalization, though personally, I don't like PCA (produces meaningless reduced variables and sensitive to outliers / correlation among variables). Here's a simpler way to normalize scores, I actually patented it.
Table of content: