Correlations in the new TOEFL era: an investigation of the statistical relationships between iBT scores, placement test performance, and academic success of international students at Iowa State University
Using data on international students at Iowa State University, this correlation study investigates the statistical relationship between scores on the new iBT version of the TOEFL and academic performance in other capacities. While many correlation studies were carried out in the 20th century to test the strength of the relationship between scores on the PBT version of the TOEFL and academic performance, there has been a curious dearth of similar inquiry concerning the iBT. By correlating the iBT scores of international students admitted to ISU with performance on the English Placement Test and grades in English classes, this study sought to evaluate the usefulness of iBT scores to the university as indicators of proficiency levels and potential for success. Correlations of iBT scores with EPT scores and class placement revealed positive but not strong relationships between performance on the two tests. During correlations of iBT composite scores and grades in English classes, highly unpredictable relationships were noted that were sometimes strongly positive, sometimes negative, and often very weak. Finally, in correlations of scores on individual sections of the iBT with grades in the same English classes, relationships were also highly variable, but sections of the iBT involving the production of language (writing and speaking) were demonstrated to usually correlate the most positively with academic performance. Overall, the results of this study suggest that, despite that iBT scores now reflect performance on integrated tasks and both speaking and writing ability, TOEFL scores remain unreliable indicators of how well students will perform on other tests and in their coursework.