4.3 Factor Analysis
The five speeded cloze-elide passages, the four C-Tests, the two multiple-choice cloze passages, and the reading comprehension passage were subjected to principal component analysis (PCA) using SPSS version 21. Prior to performing PCA, the suitability of the data for factor analysis was assessed. The Kaiser-Meyer-Olkin value was .95, exceeding the recommended value of 0.60 (Kaiser, 1970, 1974) and Bartlett’s test of Sphericity (Bartlett, 1954) reached statistical significance, supporting the factorability of the correlation matrix. Principal component analysis showed the presence of one component with eigenvalue exceeding 1, explaining 72% of the variance. An inspection of the scree plot revealed on clear break after component one which supports extraction of one factor.