The [IPIP website provides a copy of the IPIP representation of the NEO 30 facet form](http://ipip.ori.org/newNEOFacetsKey.htm).

It also provides some information [comparing IPIP NEO with official NEO](http://ipip.ori.org/newNEO_FacetsTable.htm).
However, the information provided is incomplete for making an assessment of the psychometric properties of the test. For example, I'd like to know about: (a) how items were chosen; (b) what was the sample size and characteristics used to correlation generate the comparative information provided; and (c) what is the factor structure of the IPIP NEO.

Thus, my questions:

* Where can I find information on how the IPIP NEO (30 facet version) was developed?
* What studies have examined the psychometric properties of the IPIP NEO (30 facet version) both in absolute terms and relative to the official NEO?