title: A Rejoinder.
abstract: Three commentaries on the Nesselroade and Molenaar target article in this issue are responded to in the interest of elaborating and defending the points of view expressed in our article. The commentaries feature philosophy of science, general structural modeling, and broad behavioral research perspectives. Responding to the commentaries afforded us the opportunity to clarify further matters that we deem critical to the fundamental matter of measurement in behavioral science, especially as it emphasizes (properly, we believe) the individual as the primary unit of analysis.
authors.affiliation: a The University of Virginia.
authors.forename: John R
authors.initials: JR
authors.lastname: Nesselroade
authors.affiliation: b The Pennsylvania State University.
authors.forename: Peter C M
authors.initials: PC
authors.lastname: Molenaar
mesh_terms: D035841:Behavioral Research; D001525:Behavioral Sciences; D001690:Biological Science Disciplines; D049673:History, 20th Century; D006801:Humans; D010684:Philosophy; D010685:Philosophy, Dental; D010686:Philosophy, Medical; D012106:Research; D012586:Science
keywords: Data box; idiographic filter; individual-level analysis; measurement