ACCESS is the English language examination of the Department of Immigration and Multicultural affairs (DIMA) of the Australian Federal Government to assess migration applicants’ English language skills for migration purposes. An alternative examination for the same purpose is the IELTS (General Training) module. The objective of the present study is to establish the equivalence between the measurement scales of ACCESS and IELTS (General raining). The findings would be necessary for the migration process and informative for IELTS as an international English language testing system.
The equivalence between ACCESS and IELTS can be established by administering the two tests to the same group of individuals. In such a case, only a small sample of individuals can be tested. The results from such an analysis, however, would be difficult to generalise both because the size of the sample can rarely claim representativeness and because the situation of the test administration is not typical of the actual examinations. Alternatively, actual test results from the two examination systems can be used for the establishment of the equivalence. In such a case, there is a need for links between the two sets of test results through candidates who have taken a third common test. This latter method was used in the study. The linking test chosen was the ASLPR. The IELTS (Academic) module was also included in the study to enable a complete analysis of IELTS. The analysis in the study thus included four testing systems: the IIELTS (Academic and General Training) modules, ACCESS and the ASLPR.
The statistical technique used to establish the equivalence was many-facet Rasch modelling. This is an approach for equating test scales by reference to an external measurement scale independent of the tests involved. Using Rasch modelling, equivalence among the test scales can be established from actual test results of separate ACCESS and IELTS candidate groups. The results of the equating are also highly generalisable due to the statistical modelling techniques employed.
The findings from the equating exercise have enabled the identification of the scale structures of the four testing systems. The results are most interesting both in terms of the understanding gained regarding the test scales and in terms of the methodology used.
As regards the equivalence between ACCESS and IELTS (General Training), there is a large segment of match between the ACCESS and the IIELTS scales. This provides sufficient basis for estimating the equivalence of the two scales.
The application of Rasch modelling in establishing equivalence among testing systems has also made a contribution to applied linguistic research.