The Discovery of Trajectory Equifinality ModelD

Tatsuya Sato (Faculty of letters, Ritsumeikan University), Yuko Yasuda(Faculty of Education, Kyoto University), Ayae Kido (Faculty of letters, Ritsumeikan University), Saori Takada (School of Law, Ritsumeikan University) and Jaan Valsiner (Clark University)

Qualitative Research in Psychology, 5, 255-275,2006D

@Qualitative psychology and cultural psychology are new beginnings for the discipline of psychology. These new beginnings also require a new methodology to fit the open systemic nature of phenomena. The trajectory equifinality model (TEM) is a new methodology for depicting the diversity of the course of human life. The concept of equifinality originated in the general system model of von Bertalanffy, and it means that the same final state may be reached from different initial conditions and in different ways. It is a general property of open systems. In the minimal case, the dynamics of the open systems entail the notion of individual trajectories that may diverge (at bifurcation points) or converge (at equifinality points). Therefore, the TEM maps the individual histories of particular systems onto the wider general system of possible trajectories that arrive at the equifinality point. After reviewing the historical and philosophical background of the TEM, important concepts such as the equifinality point (EFP), trajectory, bifurcation point, irreversible time, polarized EFP, and obligatory passage point (OPP) are explained. Then, three studies applying this methodology are presented so that new researchers can understand and practice this new methodology. Finally, the implications and limitations of the TEM are discussed. It is noted that all psychological research necessarily needs to analyze processes of psychological kind (rather than time-free essences that psychologists posit to "exist", like "intelligence", "personality" etc.), and TEM is a first step towards providing a workable alternative to existing statistical orthodoxy.

Trajectory equifinality model (TEM), qualitative psychology, equifinality point (EFP), trajectory, system theory

The prototype of the TEM is here.