Journal of Teaching Language Skills (JTLS) 36(4), Winter 2018, pp. 1-31- ISSN: 2008-8191 DOI: 10.22099/jtls.2018.24468.2201 Short- And Long-Term Word Clustering Effect on Vocabulary Learning of EFL Learners: A Case of Semantic Versus Phonological Clustering Seyyed Mohammad Reza Amirian  Assistant Professor Hakim Sabzevari University smr.amirian@gmail.com Mortaza Bonjakhi M.A. Hakim Sabzevari University mbonjakhi@gmail.com Golnaz Sabbaghzadeh M.A. Islamic Azad University, Neyshabour Branch g.sabbaghzade@gmail.com Abstract The aim of the current study was twofold: (1) to validate the internal structure of the general English (GE) section of the university entrance examination for Ph.D applicants into the English programs at state universities in Iran (Ph.D. UEE), and (2) to examine the factor structure invariance of the Ph.D. UEE across two proficiency levels. Structural equation modeling (SEM) was used to analyze the responses of a random sample of participants (N=1009) who took the test in 2014 to seek admission to English programs at Iranian state universities. First, four models (unitary, uncorrelated, correlated and higher-ordered) were estimated and compared to find the model that best represented the data. Then, the factor structure invariance of the test across two proficiency levels was explored using multigroup confirmatory factor analysis. The higher-order and correlated three- factor model showed the best fit to the data. The result also showed that the structure of the test remained invariant across both proficiency levels. These results supported the multi-componential view of language proficiency. It was found that there was no relationship between levels of language proficiency and the structure of the test. However, the results called into question the score- reporting policy for the PhD UEE and led to the conclusion that a single total score does not reflect the structure of the test. Keywords: factor structure invariance, language proficiency, multigroup confirmatory factor analysis, university entrance examination Received: 09/02/2017 Accepted: 06/02/2018  Corresponding author