A Short-Cut Method of Fitting a Logistic Curve
William A. Spurr, David R. Arnold · Journal of the American Statistical Association · 1948
“Growth” curves have been used in many fields despite the extensive calculations required. These curves may be applied even more widely if their construction can be simplified. This article shows how to fit a logistic (Pearl-Reed) curve quite simply by means of a nomograph (which determines the upper limit from three selected points) and a logistic grid (which reduces the curve itself to a straight line). 1 1 The writers are indebted to Professors Albert Bowker and Alfred Niles of Stanford University for suggestions on this paper. Other “growth” curves may be fitted by constructing appropriate graphs.