Continuous variable only indicator of latent variable

[gemmafu]

In previous messages I clarify my doubt about the composition of a latent variable, which can be formed by a single indicator. But if the latent variable is endogenous, can I use a continuous variable to form this latent variable?
Can an author tell me to justify it?
Thank .

[cringle]

You can use a single-indicator construct; but you need to find a theoretical or conceptual justification.

Kind regards
Christian

[ploylyjung]

Dear Prof. Christian,
I still don't understand that continuous variables can be used to form latent variables? In one of my latent variable, there are three manifest variables I want to use to form a latent variable. These are continuous, binary, and ordinary variables. Can I use three type of variables to form a latent variable at the same time?

Looking forward to hearing from you.
Regards,

[cringle]

No, that's not possible. You need metric or quasi-metric indicator data.

Best
Christian