Sentence:  Exploratory <WSD>factor analysis</WSD> (EFA) and principal components analysis (PCA) both are methods that are used to help investigators represent a large number of relationships among interval-level variables in a simpler (more parsimonious) way. 
Meaning of the word marked with <WSD> tags:  A statistical method used to describe variability among observed correlated variables in terms of one or more unobserved variables (called factors).