Validation of the Common Metric Scale (CMS)

Validation of the Common Metric Scale (CMS)

  On the basis of the Parallel Developmental Sequence (PDS) Model (Kim & Kwon, 2005, 2007), Kim (2006) proposed the Common Metric Scale (CMS) Model for measuring language ability. The CMS was developed in terms of the Interlanguage (IL) approach, the Testability, and the Bounded-domain hypothesis. The IL approach enables us to map the PDS onto the CMS. Thus, the absolute scales, the scale calibration, and the scale descriptions of the CMS can be automatically defined. In addition, the Testability hypothesis enables us to gear test tasks to the Parallel Stages of the PDS, and the Bounded-domain hypothesis enables us to synchronize test domains with IL discourse domains. Thus, the resulting CMS satisfies what we call the triple implicational scales in which the scales, the scale descriptors, and the task hierarchies are all in an implicational relationship. To validate the theoretical CMS, the Spearman Correlation and the Kruskal-Wallis Test were conducted. The results demonstrated that the CMS has its own validity. In sum, the CMS based on the PDS can function as an IL-sensitive scale for identifying IL learners" current developmental stages, diagnosing the deficiencies in their IL grammar, and predicting what rules or structures will be learnable or teachable next, thereby giving them a "timely remedy and tailored teaching".