  Individual scores on common factors are required in some applied settings
(e.g., business and marketing settings). Common factors are based on reflective
indicators, but their scores cannot unambiguously be determined. Therefore,
factor score estimates and unit-weighted scales are used in order to provide
individual scores. It is shown that these scores are based on treating the
reflective indicators as if they were causal-formative indicators. This
modification of the causal status of the indicators should be justified.
Therefore, the fit of the models implied by factor score estimates and
unit-weighted scales should be investigated in order to ascertain the validity
of the scores.
