1 Introduction
High-stake tests are a common practice in our society and their obtained scores are
claimed to represent the candidate’s proficiency in English and provide relevant
evidence in decision-making process for mainly three purposes: selecting people
for an occupation, issuing a certificate, and permitting one to enter a higher education
organization. Scholars and researchers agree that considering construct validity is the
most important aspect in test validation (Bachman and Palmer 1982; Cronbach 1984;
Bachman 1990, 2000; Brown 2000). IELTS (International English Language Testing
System) and TOEFL iBT (Test of English as a Foreign Language, Internet-based
Test) are two common examples of these high-stake standardized tests playing a
critical role in determining the future life of their candidates. Among the four
language skills included in these two exams, speaking, because of measurement
difficulties, has received less attention in the available literature. The aim of this
study is to investigate and compare the construct validity of the speaking module in
IELTS and TOEFL iBT exams