

Reference about the inapropiate use o... 

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marina saiz posted on Saturday, January 21, 2006  11:04 am



I am trying to test if four variables ( different reading test) can be grouped into two constructs or just one. My hypothesis is that is should be two and not one. For my dissertation proposal I plan to use Principal Component Analysis and Confirmatory Factor Analysis. Once I have collected the data, if I run Exploratory Factor Analysis either by principal component analysis or by maximum likelihood, I obtain only one factor. If I run CFA, the two factor model fits better than the one factor model. The problem is that the four variables correlate more than .7 each other. I think that the correlation can be explained because one resulting construct could be dependent on the other, and that is theoretically possible ( One factor is decoding words aloud, the other is decoding and identifying the meaning). I have been told that if there is a dependence relationship between the resulting constructs, EFA is useless and I should use Confirmatory Factor Analysis, but I can’t find any reference to document that. Do you know of any reference that talks about the inappropriate use of EFA when there is a relationship of dependence among the resulting constructs? 

bmuthen posted on Saturday, January 21, 2006  1:40 pm



If a 2factor CFA model fits better than a 1factor model, it seems like EFA would be able to show those same 2 factors. If one factor influences the other, the factors are correlated. I don't see how that would invalidate the EFA. Even in an EFA with uncorrelated factors (orthogonal solution such as with Varimax rotation), we know that an equivalent representation of the observedvariable correlation matrix can use correlated factors (oblique solution, such as with Promax rotation). 

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