I'm pretty new to Latent class analysis, and I obviously still have a lot to learn.
I have a data set with 10 000 observations and 20 variables. I'm trying plot the probabilities of each of my identified classes in the latent class analysis I did using the poLCA package in R (http://cran.r-project.org/web/packages/poLCA/poLCA.pdf).
What I'm trying to do is something like Figure 1 in Quek et all. 2013 (http://www.researchgate.net/publication/258441959_Concurrent_and_simultaneous_polydrug_use_latent_class_analysis_of_an_Australian_nationally_representative_sample_of_young_adults)
The problem is that every time I run the poLCA() function, my plot changes, so do the the probabilities of each class and of course this is because the results of the poLCA() changed.
Is this normal that doing two or more times the same thing with the same data I get different results ? I'm feeling very uncomfortable here, so if someone could explain me what's happening here, I could maybe live with myself again :)