Previous research has been limited regarding the measurement of computational thinking, particularly as a learning progression in K-12. This study proposes to apply a multidimensional item response theory (IRT) model to a newly developed measure of computational thinking utilizing both selected response and open-ended polytomous items to establish the factorial structure of the construct, apply the recently introduced composite and structured constructs models, and to investigate the measurement invariance of the assessment between males and females using the means and covariance structures (MACS) approach.