In a 2-Term Phrase, Which Term is more Important?

Dr. Garcia (Orion) let me know of an updated paper on his site (Targeting Documents and Terms Through Co-Occurrence Data) regarding a method for finding which of 2 terms in a 2-word phrase has a higher probablity of being targeted/found by the search engines in FINDALL mode (which is the default at all of the major SEs). It's unusually concise for a paper of his and should be worthwhile 5-10 minute reading for any SEO who wants to know how to perform an analysis of a phrase.

The example Dr. Garcia uses is "car insurance" and he shows, clearly, how to arrive at the fact that a page targeting the phrase would do better to optimize leaning towards "insurance" than "car".