Omitted variable bias occurs in most statistical models. Whenever a confounding variable that is correlated with both dependent and independent variables is omitted from a statistical model, estimated effects of included variables are likely to be biased due to omitted variables. This issue is particularly problematic in physics education research…

Deterministic chaos which involves orderly motion is discussed. Presented is the history of chaos and two tests for chaos. Practical applications and predictions of the long-term significance of chaos research are discussed. (KR)

Proposes the triangulation of two qualitative research methods, hermeneutics and grounded theory, to illuminate clinical realities that elude alternative approaches. Discusses how hermeneutics reveals perceptual information about the uniqueness of shared meanings and common practices, and how grounded theory provides a conceptual framework useful…