Dynamical models for psychological assessment: Phase space functions.

Abstract

This article examines the implications of phase space functions for psychological assessment. Behavior problems, causal variables, and causal relationships are dynamic and demonstrate complex nonlinear and discontinuous relationships. Measuring the temporal, dynamic, and nonlinear dimensions of variables can enhance the accuracy of predictions of the future time course of variables and of the strength of causal relationships for behavior problems. Cross-sectional, longitudinal, and time series research designs are prone to inferential errors because they often fail to consider the dynamic time course functions of variables. The value of a variable (its stale) coupled with the current direction and rate of change of the variable (its phase), at a single measurement point, is its phase state. Equal state values across persons on a variable dimension does not mean that those persons are in equal phases on that variable dimension.

Modeling Unipolar Depression as a Chaotic Process.

“…In a special section of Psychological Assessment on chaos theory, a number of researchers (Haynes, 1995;Haynes, Blaine, & Meyer, 1995;Heiby, 1995aHeiby, , 1995b presented as a tenet of behavioral assessment that nonlinear dynamical analysis tools are needed when studying human behavior that is potentially complex and unstable. Specifically, frequent-interval time series data that have been inspected for linear, nonlinear, chaotic, and random components are necessary to adequately capture the behavior of interest.…”

The action formulation: A proposed heuristic for clinical case formulation

“…Intimately related to FACCM is work conducted by Heiby, as well as by Haynes and his colleagues, on the application of chaos theory to clinical assessment (Heiby, 1995a(Heiby, , 1995bHaynes, 1995;Haynes, Blaine, & Meyer, 1995). As argued by these authors, many models of clinical assessment are predicated upon an untenable assumption that the putative clinical outcomes are stable, or at least cyclical, and that they are linearly related to causal factors.…”

At the Edge of Chaos

“…attractor portraits (see Figure 1) to characterize and explore such systems (Hilborn, 1995). But the central methodology involves the analysis of time series (Haynes, Blaine, & Meyer, 1995).…”