Single Indicator Reflective/Formative LV

[vidhula]

Hai

I have a question about LVs with single indicators. How do I establish validity of the same? Would it be based just on theory or is there any computational method of assessing its validity?

Also, is there any difference between a single-indicator formative and single-indicator reflective LV when it comes to the PLS algorithm in SmartPLS?

Thanks.
Vidhula

[nayabeyes]

According to Hair et al., (2013). A primer on PLS-SEM - Book), in case of two stage approaches, they mentioned that LVs measured with only one indicator are set equal to this indicator, no matter which measurement model setup is chosen (single-item constructs; pp.264-265).
So I think, in case of single item, no matter formative or reflective is used.
For validity, it is very difficult to validate single item measure. I think it is based on theory rather than computational method.

[vidhula]

Thanks Murad. I believe my single indicator LVs do have a strong theoretical basis. Will argue along the same lines. :)

[nayabeyes]

Check Hair et al., 2013. A primer on PLS-SEM – Book for using single item.
If cannot find book then check the papers as follows:
Hair et al 2012 An assessment of the use of partial least squares structural equation modeling in marketing research
Hair et al 2012 The Use of Partial Least Squares Structural Equation Modeling in Strategic Management Research: A Review of Past Practices and Recommendations for Future Applications