Rasch testlet model and bifactor analysis: how do they assess the dimensionality of large-scale Iranian EFL reading comprehension tests?

Language Testing in Asia

Table 1 Testing unidimensionality of the EFL reading comprehension tests using the unified parallel analysis method

Statistic	Examination year
Statistic	2016	2017	2018
Second Eigenvalue in the observed data	0.89	0.64	0.47
Average of second Eigenvalues in Monte Carlo samples	0.23	0.21	0.17
Monte Carlo samples	100	100	100
p value	0.001	0.001	0.001
Result of testing unidimensionality	Rejected	Rejected	Rejected