ERIC Number: EJ834393
Record Type: Journal
Publication Date: 2005-Jan
Reference Count: 7
Rejoinder to Rogosa's Commentary on "A Manifesto on Psychology as Idiographic Science"
Molenaar, Peter C. M.
Measurement: Interdisciplinary Research and Perspectives, v3 n2 p116-119 Jan 2005
This article presents a rejoinder to Rogosa's (2004) commentary on the author's (Molenaar, 2004) focus article titled, "A Manifesto on Psychology as Idiographic Science." The expert commentary of Rogosa brings up some central issues that require careful evaluation. The basic message of the author's focus article was straightforward: In general, there exists no relation between the results obtained in analyses of interindividual variation (IEV) and the results of analogous analyses of intraindividual variation (IAV). This far-reaching conclusion follows directly from general mathematical-statistical theorems, the so-called classical ergodic theorems. It concerns the fundamental difference between the phenomenon of IEV (individual differences) and the phenomenon of IAV. The author stresses that this fundamental difference pertains to the kind of variation itself: variation between participants (IEV) on one hand and variation within a participant (IAV) on the other hand. Rogosa (2004) discussed a number of statistical model types such as individual growth-curve models and other so-called individual-unit models. The models referred to have been applied only in analyses of IEV but never in analyses of IAV. However, that is not mandatory; the renewal models mentioned by Rogosa, for instance, have important applications in intraindividual signal analysis of, for example, cardiac interbeat intervals. The important question is whether applications are to IEV or to IAV, knowing that in general the results may differ in arbitrary ways if the empirical processes under scrutiny are nonergodic. In this rejoinder, the author elaborates these qualifications further with respect to the simplest version of the individual growth-curve model referred to by Rogosa. He explains that the individual growth-curve model is an instance of T-technique as defined by Cattell (1963) and hence, pertains only to analysis of IEV.
Descriptors: Intervals, Psychology, Individual Differences, Models, Statistics, Data Analysis, Measurement
Psychology Press. Available from: Taylor & Francis, Ltd. 325 Chestnut Street Suite 800, Philadelphia, PA 19106. Tel: 800-354-1420; Fax: 215-625-2940; Web site: http://www.tandf.co.uk/journals
Publication Type: Journal Articles; Opinion Papers
Education Level: N/A
Authoring Institution: N/A