Generally, EFA programs do not allow you to specify or fix loadings to pre-determined values. That’s a problem that needs to be fixed in EFA software. (I want us to have our cake and eat it too.) In contrast to the exploration implicit in EFA, a factor analysis in which some loadings are fixed at specific values is called a Confirmatory Factor Analysis. The analysis is confirming one or more hypotheses about loadings, hypotheses representing by our fixing them at specific (usually 0) values. Below is shown the path diagram of a confirmatory analysis model one in which the primary – loadings are represented but the secondary, aka, cross loadings are set to 0. In the diagram, a loading or correlation that has been set to 0 is simply left out of the diagram. Hmm. The path diagram is certainly simpler than that of an EFA. It turns out that the mathematics of CFA is simpler also, resulting in CFAs being used for most relations studies structural equation models. – EFA vs. CFA of Big Five testlets Start 11/6 The data are from Wrensen & Biderman (2005). The 50 Big Five items were used to compute 3 testlets (parcels) per dimension. More on why testlets were used later. A testlet is a mini-scale the mean of 2-5 items. Here, each was the mean of 3 items. – More on testlets in a few pages. Data were collected in two conditions honest response and fake good. The honest – response data will be analyzed here.
Generally, EFA programs do not allow you to specify or fix loadings to pre-determined values. That’s a problem that needs to be fixed in EFA software. (I want us to have our cake and eat it too.) In contrast to the exploration implicit in EFA, a factor analysis in which some loadings are fixed at specific values is called a Confirmatory Factor Analysis. The analysis is confirming one or more hypotheses about loadings, hypotheses representing by our fixing them at specific (usually 0) values. Below is shown the path diagram of a confirmatory analysis model – one in which the primary loadings are represented but the secondary, aka, cross loadings are set to 0. In the diagram, a loading or correlation that has been set to 0 is simply left out of the diagram. Hmm. The path diagram is certainly simpler than that of an EFA. It turns out that the mathematics of CFA is simpler also, resulting in CFAs being used for most relations studies – structural equation models. EFA vs. CFA of Big Five testlets Start 11/6 The data are from Wrensen & Biderman (2005). The 50 Big Five items were used to compute 3 testlets (parcels) per dimension. More on why testlets were used later. A testlet is a mini-scale – the mean of 2-5 items. Here, each was the mean of 3 items. More on testlets in a few pages. Data were collected in two conditions – honest response and fake good. The honest response data will be analyzed here.
p5510_lec09_efa2_cfa1_lavaan.docx