Since the instigation of the national customer satisfaction indices (CSI), partial
least squares (PLS) has been used to estimate the CSI models in preference to structural
equation models (SEM) because they do not rely on strict assumptions about the data.
However, this choice was based upon some misconceptions about the use of SEM’s and
does not take into consideration more recent advances in SEM, including estimation
methods that are robust to non-normality and missing data.