ApolloChoiceModelling forum

I'm planning a discrete choice experiment (DCE) and intend to analyze the data using latent class analysis (LCA). My design has 4 attributes, 10 choice sets, and 3 alternatives per choice set (2 substantive alternatives + a no-change/opt-out option).
I ran a pilot survey with 20 participants and estimated the required sample size following de Bekker-Grob et al. (2015), which is based on a mixed logit model.
My question: how do I adapt or extend this kind of power/sample size analysis for a latent class model, given that the number of latent classes is not known in advance? Specifically, rule-of-thumb approaches like de Bekker-Grob et al. assume a single (or mixed) population-level model; LCA instead estimates class-specific parameters for an a priori unknown number of classes with unknown relative sizes. Is there an established way to translate a mixed-logit-based sample size estimate into a minimum-N recommendation for LCA?
Any guidance, relevant references, or rules of thumb would be very helpful.


References
de Bekker-Grob EW, Donkers B, Jonker MF, Stolk EA. Sample Size Requirements for Discrete-Choice Experiments in Healthcare: a Practical Guide. Patient. 2015 Oct;8(5):373-84. doi: 10.1007/s40271-015-0118-z. PMID: 25726010; PMCID: PMC4575371.

Hi,

I am not aware of techniques for efficient experimental design for discrete choice latent class models. That said, Ngene is the leading software for generating discrete choice experimental designs, so you may want to look into it. A quick glance through their manual did not return a match for latent class designs, but I recommend you search further.

In principle, if you know the asymptotic covariance matrix of your model (be it latent class or any other), you could write a software routine to search for an experimental design with a low D-error. Not sure how easy it would be, though, and you would still need priors for the class allocation parameters, as well as a good guess at how many latent classes you would get. If you are interested in this path, Alcorta & Mariel (2026) already calculated the asymptotic covariance matrix of a latent class choice model with linear utility functions.

Best wishes,
David