Reading on a paper on factor analysis and measurement invariance I find the description of some functions as 'ogival' functions.
In Google I find it referenced mostly in papers from the '70s and '80s. Seems a term that fell out of fashion as I see only one mention of 'ogives' in this whole site. The Wikipedia page says it describes an empirical CDF, but from some of these plots and articles (e.g. this article from 1975, p.317) it seems that ogival curves are used to refer to any sigmoidal function? Where is it defined?