Using item response modeling methods to test theory related to human performance.

Testing theories of human performance requires measurement of latent constructs like performer perception and motivation, intrinsic parts of performance, but nebulous to assess. Item response modeling (IRM) methods model latent constructs directly and thus can assist in the development and testing of theory. This article presents an application of IRM methods in initial testing of the Movement Continuum Theory. A construct was derived from the theory, and an instrument was generated to put the construct into operation. Over 300 people of varying movement abilities, aged 18 to 101, completed the 24-item Movement Ability Measure, a self-report questionnaire asking for participants' perceptions of their current and preferred ability to move. Wright Maps derived from estimated locations of participants and item thresholds showed the strong relationship between the theorized construct and the empirical data. Data gathered with the instrument and analyzed with IRM methods provided mixed support for principles of the theory.