| __MMU - Bio. Sci., MSc Multivariate Statistics: Principal components analysis__ *(Site not responding. Last check: )* |

| | **PCA** is one of a family of related ordination or projection techniques that includes Factor **Analysis** and **Principal** Co-ordinates **Analysis**. |

| | Note: it is **Principal** ('first in rank or importance' Concise Oxford Dictionary) not Principle ('a fundamental truth or law as the basis of reasoning or action', Concise Oxford Dictionary). |

| | **PCA** and FA are two similar methods, indeed under certain circumstances (no rotation and number of factors = number of variables) they produce identical results (albeit with some rescaling of the eigen vectors). |

| obelia.jde.aca.mmu.ac.uk /multivar/pca.htm (223 words) |